Tuesday, September 13, 2016

Intersymbol Interference in Binary Communication Systems

#WA8UNS @WA8UNS #ridgefieldct #Ridgefield @ridgefield in #FairfieldCounty #CT #Connecticut Thomas Q Kimball of Ridgefield, Connecticut wanted to share my fathers work for educational purposes.

In my father's phd publication Intersymbol Interference In Binary Communications by C.V. Kimball in which he mentions to things here in this blog posting: Iterated Switched-Mode Receiver in which the below shows his Patent US3611149 also mentioned in his Forward in his Intersymbol Interference In Binary Communications phd publication "This report considers a practical problem in underwater communications - intersymbol interference. And the above contributions should be of considerable importance to a designer of a underwater communications system." In which I am proud to show and share his Acoustic Communication Studies (U) An experimental study of techniques for Submarine to Submarine Communication System as seen below. 


Please click below to see in a Pdf format

Technical Report No. 195
3 674- 18-T
INTERSYMBOL INTERFERENCE IN BINARY
COMMUNICATION SYSTEMS
by Christopher V. Kimball
Approved by T. G. Birdsall
COOLEY ELECTRONICS LABORATORY
Department of Electrical Engineering
The University of Michigan
Ann Arbor, Michigan
for
Contract No. Nonr-1224(36)
Office of Naval Research
Department of the Navy
Washington, D.C. 20360
August 1968
Reproduction in whole or in part is
permitted for any purpose of the U. S. Government.

Christopher Vernon Kimball   1968
All Rights Reserved

When a binary communication system transmits symbols through a bandlimited channel, the received symbols will generally overlap in time, giving rise to intersymbol interference. In the presence of noise, intersymbol interference produces a significant increase in the system probability of error. The problem of intersymbol interference and noise is considered here for known,linear, time invariant channels and with added white Gaussian noise. Although a particular underwater acoustic channel is used as a source of motivation, the results presented are equally applicable to other communication channels. Traditional approaches to the intersymbol interference problem spectrum and transversal (time) equalization are examined. A basis for the comparison of intersymbol interference problems using the concept of phase equalization, is given. A major assumption which limits the interference to that caused by adjacent symbols is made. This assumption is shown to be equivalent to restricting the transmitter to reasonable signalling rates relative to the bandwidth of the channel power spectrum. All subsequent analysis and evaluation are done under this assumption. Several linear filter receivers prevalent in the literature the matched filter receiver, the transversal filter receiver, and the optimized linear filter receiver are reviewed and evaluated. Two easily implemented nonlinear receivers, the switched-mode receiver and the iterated switched-mode receiver, are considered as alternatives to the more complex optimized linear filter receivers. The iterated switched mode receiver, which is described for the first time here, is shown to perform better than any optimized linear receiver when intersymbol interference is moderate. Finally, the optimum (likelihood ratio) receiver is described and evaluated to provide an absolute lower bound on error probability for a given intersymbol interference problem. A comparison of the error performance of the receivers shows that if intersymbol interference is reduced to moderate amounts by proper choice of signalling rate, then the easily implemented iterated switched-mode receiver gives near intersymbol interference free performance. For higher signalling rates and consequently larger amounts of intersymbol interference more complicated receivers are required to achieve near optimum performance and even the performance of the optimum receiver is significantly worse than intersymbol interference free performance.

This report considers a practical problem in underwater communications intersymbol interference. Four major contributions are presented. First, the extent of intersymbol interference in a given situation is shown to be dependent on the autocorrelation function of the received symbol instead of the received symbol itself. Examination of the received symbol usually indicates more intersymbol interference than is actually present. Second, several traditional and proposed receivers are compared on a consistent basis, indicating the trade-offs between system error performance and system complexity. The optimum (likelihood ratio) receiver is included in the comparison to provide a lower bound on error performance.Third, an easily implemented nonlinear receiver whose performance is close to that of the optimum receiver in many practical cases is described. Finally, a rule-of-thumb is given which relates transmission rate, error performance, and system complexity. The above contributions should be of considerable importance to a designer of an underwater communication system.

CHAPTER I
INTRODUCTION
This paper is the result of a study of the general underwater acoustic communications problem, using experimental results from a comparatively well-known channel. Because of the complexity of the general problem, a specific, but important aspect of the problem, is considered: intersymbol interference in binary signalling systems. Restriction to binary signalling systems provides considerable simplification in both analysis and implementation. Intersymbol interference occurs in such systems when the received symbols overlap one another in time, increasing the probability of error. Channel phenomena which produce irregularities in the received power spectrum, such as multipath and selective fading, are sources of intersymbol interference. Although underwater acoustic channels are the frame of reference for this study, application to other channels is easily accomplished. For binary communication systems in the absence of intersymbol interference, the classical theory of signal detectability provides the basis for the design of the optimum (likelihood ratio) receiver (Ref. 1). Only a limited number of studies have been made which consider the intersymbol interference problem, however. These studies deal with the determination of the optimum linear filter receiver for a given situation (Refs. 2, 3, 4). Aein and Hancock have demonstrated an easily implemented nonlinear receiver which is superior in performance to their optimum linear receiver (Ref. 2). A major objective of this paper is to extend the theory of signal detectability to intersymbol interference problems by analysing and evaluating the optimum (likelihood ratio) receiver. A comparison of the above receivers with those used in practice is also made. In subsequent discussion, we often refer to experimental results from the Miami to Bimini test facility of the Michigan-Miami ("Mimi") project as a source of motivation (Ref. 5). Some significant aspects of the Mimi channel are sketched in the next section. We then discuss the working assumptions of the paper and ways in which these assumptions may be relaxed. Finally, the major conclusions and contributions of the thesis are summarized. 1. 1. The Mimi Channel The Mimi project is a joint effort by the Institute of Marine Science of the University of Miami and Cooley Electronics Laboratory of the University of Michigan. The Mimi test facility has two features which distinguish it from other facilities. First, both the transmitter and receiver hydrophones are in permanently fixed positions. This allows repetitive study of exactly the same physical channel. Second, very stable (1-2 parts in 10 ) oscillators are available at both the transmitting and receiving sites, which allow coherent averaging and analysis of the receptions. In this section we will sketch the physical structure of the channel and several of its features which are relevant to the communications problem. The basic Mimi channel consists of a transmitting transducer and reflector at Fowey Rocks near Miami, Florida, and receiving hydrophones at North Bimini Islands, Bahamas, 43 miles to the east as shown in Fig. 1. 1. For the first 13 miles from Fowey Rocks the depth is sloping to 400 meters. Near the end of this shelf is the mean center line for the Gulf Stream, which is a source of turbulence. Beyond the first 13 miles the depth drops off abruptly to 800 meters until Bimini is reached. Ray path computations indicate bottom reflection combined with surface reflected and/or refracted modes of propagation in the channel. Two fundamental limitations are placed on the channel by the transmitting transducer and reflector. The first is that the nominal bandwidth of the transducer is 100 Hz centered at a 420 Hz carrier frequency. This limitation is due to the construction of the transducer and the beam forming reflector. One can view the bandwidth restriction by considering the "Q" (center frequency/bandwidth) of the system, which indicates the system is wide band, i.e., 1.0 MHz at 4. 2 MHz would be a wide band in HF radio. Alternatively, when typical information rates are considered, the system appears narrowband, i. e., a 100-wpm teletype requires a bandwidth of at least 80 Hz. We see that, relative to common information rates, bandwidth is a significant limitation.




The second limitation due to the transmitting transducer is a peak power limitation. Ceramic elements in the transducer are subject to fracture and/or fatigue at high power levels. Because of the great difficulty and expense involved in obtaining a replacement transducer, the system is normally operated well below its specified rating. Even if more durable transducers were available, cavitation in the water surrounding the transducer would provide a peak power limitation. The effect of the peak power limitation on the communications problem is to severely limit the waveforms which may be transmitted~Noise is a major problem in the Mimi channel. In traveling the 43 mile distance a signal is attenuated by 105 to 135 db, yielding S/N ratios in the range -10 db to + 20 db in a 100 Hz band. The precise form of the noise is largely unknown at the present time. Nonthermal noise such as ship or biological noise is known to be present, and hence an accurate description of the noise would be difficult. Two types of signals have been used to measure the channel spectral characteristics: continuous wave (CW) signals and periodic pseudo-random (PR) signals. CW signals allow high S/N analysis of a single spectral line, usually at the 420 Hz center frequency. Results of these CW transmissions indicate very slow (less than 10 cycles per day) phase changes of the received signal relative to the coherent reference. During these same tests the amplitude of the reception was noted to fluctuate considerably, occasionally becoming undetectable. Two tone (two simultaneous CW) tests indicate similar phase characteristics on both spectral lines, but with independent amplitude characteristics. Both forms of the CW experiment suggest the Mimi channel is amazingly phase stable and subject to a time variant frequency selective fading. The wide band PR signals can be employed to measure the spectrum of the Mimi channel. This spectral analysis is done by crosscorrelating the received signal with the original pseudo-random signal and then performing deconvolution techniques to obtain the complex channel spectra. Figure 1.2 shows a typical complex impulse response and corresponding spectrum based on a 5-minute coherent time average of data taken in February 1965.  Figure 1.3 shows the autocorrelation of the impulse response and the corresponding spectrum, which is the channel power spectrum.  The plotted data (which has been subjected to discretionary filtering) is believed representative of the form of the spectra to be expected in the Mimi channel. From the spectra of Figs. 1. 2 and 1. 3, the selective fading effects of multipath are apparent. Two distinct null frequencies in the effective 50 Hz bandwidth are indicative of selective fading. The linear In this and subsequent discussions of the channel, we represent the real bandpass waveform as a complex low pass waveform as is usually done. The complex low pass waveform is given by M(t) ej 0t) where M(t) is the magnitude waveform and 0(t) is the phase waveform. The physical bandpass waveform is given by M(t) cos [ 2r(420)t - 0(t)] 
**
The autocorrelation function is a conjugate symmetric complex waveform because of the complex low pass representation of the impulse.
The autocorrelation of the physical bandpass waveform is given by one-half the real part of the complex autocorrelation.



Figure 4.3 An Implementation of the ISMR 

Iterated Switched-Mode Receiver  Patent US3611149
Iterated Switched-Mode Receiver Figure 4. 5 depicts the probability of error for the ISMR and the MFR, TFR and OLFR. The outstanding feature of this figure is that for Ir(T)l <.25, the ISMR performs better than any linear receiver. For Ir(T)I >.25, the ISMR performance is nearly that of the OLFR3  By comparing Figs. 4. 4 and 4. 5, we see that the ISMR performance is superior to that of the SMR for Ir(T) <. 4. Thus the ISMR is an excellent performer in moderate intersymbol interference and an acceptable performer under more severe conditions. The ISMR shares with the SMR a significant ease of implementation. The ISMR can be implemented using one digital delay (i. e., flip-flop) and one analog delay of T seconds, which is easier to obtain than the long analog delays required by the TFR and OLFR. As with the SMR, only a single variable r(dk_, dk+l) must be changed as p(t) changes and this variable is easily computed from  p(t) The ISMR represents an increase in complexity over the SMR. If a communication system is designed so that on the average, the intersymbol interference is only moderate, i. e., Ir(T) <. 25, the ISMR is an excellent choice of receiver. Since larger amounts of intersymbol interference lead to considerable increases in the probability of error for any receiver, one might use Ir(T)l <.25 as a reasonable restriction. Thus the ISMR is an important receiver in communications systems with intersymbol interference and noise. As a final comparison, consider a system for the Mimi channel shown in Figs. 1. 2 and 1. 3 which uses the 60-ms perfect word symbol shown in Figs. 2. 10 and 2. 11. When this symbol is transmitted through the Mimi channel, approximately 94% of the signal energy is within 2T = 120 ms for the phase-equalized received symbol, and hence the M =1 assumption is valid. The value of r(T) found from the autocorrelation function of the received symbol is found to be -. 2. Assuming a d of 10, which corresponds to a received S/N of approximately 3 in a 50 Hz band (+ 4.0db), the probability of error for an interference-free receiver is. 00078. For a simple MFR the probability of error is. 0076, approximately 10 times that of the interference-free receiver; for a traditional TFR, the probability of error is.0019 or about two and a half times that of the interference-free receiver. In the same conditions the ISMR has a probability of error of only.00099. Table 4. 1 gives these results.

CHAPTER V
THE OPTIMUM (LIKELIHOOD RATIO) RECEIVER
Up to this point we have considered receivers which either represented reasonable approaches to the problem, such as the TFR or ISMR, or gave optimum system performance over a specified class, such as the OLFR. In so doing, we have neglected a well-known result from decision theory that states that optimum binary decisions (under any reasonable criteria) should be based on likelihood ratio. None of the receivers discussed so far base their decisions on likelihood ratio and, consequently, they are suboptimum in the absolute sense. The reason for the neglect of likelihood ratio in earlier receivers for the intersymbol interference in noise problem stems from the inherent difficulties of the general problem. By imposing the requirement of phase equalization and a unit degree of intersymbol interference (M = 1) analysis and evaluation are possible. Operating equations for the optimum receiver with M & 1 have been derived; however, the equations are quite complicated and offer no hope of evaluation. As mentioned in Chapter II, for reasonable signaling rates, the M = 1 assumption is acceptable and hence the results presented here have practical
*
If there is no intersymbol interference ( Ir(t)l = 0), any of the linear filter receivers bases its decisions on likelihood ratio, as can be seen from classical detection theory. importance. Because of the difficulties inherent in implementing the optimum receiver, even for M =1, the subsequent analysis is, in a sense, a mathematical exercise. Only in the most critical applications could the complexity of the optimum receiver be justified. The major benefit obtained from the analysis is the absolute bound on system performance which it gives and the method of operation it suggests. The lower bound on probability of error derived shows to what extent intersymbol interference is a fundamental problem and the optimum receiver's method of operation provides guidelines for the development of practical suboptimum receivers. The following section reviews the concept of likelihood ratio and derives the operating equations for the optimum receiver. In the second section, the time symmetry produced by phase equalization is used to evaluate the receiver performance in a relatively simple manner. Finally the performance and operation of the optimum receiver is compared to the performance and operation of the receivers studied earlier. 5.1. Operation of the Receiver This section reviews the basic concept of likelihood ratio which provides the basis for the optimum receiver's design. A convenient transformation of the likelihood ratio is introduced which allows sequential operation and analysis of the receiver. Using this transformation, the operating equations for the receiver are derived. Likelihood Ratio Let x be the total reception, a waveform of duration (m + 2)T and let b  be the value of the kth symbol in x. In the reception x k there are components of other symbols whose values are independent of bk, and added white, Gaussian noise. The likelihood ratio of the reception x for the kth symbol lk(x) is defined by p(x bk = + 1) k(x)   p(xbk      1)                 (5.1) where p(x I bk= ~ 1) is the conditional probability (or probability density) of the waveform x given that the kth symbol has the specified value. A major result from binary decision theory states that the likelihood ratio lk(x) (or any monotone function of it) is the best possible indication of the value of the kt symbol. For the case in which the symbol values bk = 1 are equiprobable and in which both types of error are equally costly, as they are here, the classical theory requires that lk(x) be compared to a threshold of one. If lk(x) is greater than or equal to one, a dk=+ 1 decision is made, if lk(x) is less than one, a dk=-1 decision is made.**
*More elegant definitions of likelihood ratio are available but unnecessary for our analysis.
**The decision when lk(x) is equal to one is arbitrary, the decision indicated here is simply a convention.
Chapter VI
CONCLUSIONS AND FUTURE STUDIES
In this chapter we state the major conclusions of this paper and the future studies which they suggest.
6.1 Conclusions Chapter II showed that the amount of intersymbol interference can be related to the power spectrum or, equivalently, on the autocorrelation function of the received symbol. This relationship was shown from the existence of a waveform of minimum RMS time duration which could be obtained through the use of a phased equalizing filter. Ripples or notches in the power spectrum increased the RMS time duration of the received symbol and consequently increased intersymbol interference. Thus intersymbol interference could be viewed intuitively as a result of signaling too fast for the bandwidth of the channel. The dependence of intersymbol interference on power spectrum is important because the usual (unequalized) channel symbol response often appears to indicate much more intersymbol interference than is actually present. The dependence on power spectrum also indicates that the linear variations of different slopes in the channel phase spectrum believed to be caused by multipath effects do not produce intersymbol interference. Instead, the notches in the power spectrum caused by multipath effects (selective fading) are the source of intersymbol interference. By examining the actual channel power spectrum, an intuitive idea of a reasonable signaling rate can be obtained. The optimum (likelihood ratio) receiver was derived and evaluated under the assumption of phase equalization and limited intersymbol interference. The results of this analysis are important not because we would ever implement the optimum receiver, but because of the insight into the design of suboptimum receivers which it provides. Since the optimum receiver is a nonlinear receiver, the receiver designer should look for good nonlinear suboptimum receivers instead of the best linear filter receiver. The performance of the optimum receiver also provides an important lower bound on the probability of error in a given situation. Several common or proposed suboptimum receivers have been compared with the optimum receiver on the same frame of reference: phase equalization and limited intersymbol interference (M = 1). From this comparison the system designer can determine the relative merits of the various receivers for his particular problem. The results of this comparison provide another important guideline to the system designer. If the received signal has I r(T)I <.25 then an easily implemented receiver (ISMR) can provide near ideal performance. On the other hand, if I r(T)I >.25 more complicated receivers must be used and even with these receivers the probability of error is significantly increased. From a practical point of view, then it is very desirable to reduce the signalling rate so that I r(T)I <.25. An easily implemented nonlinear receiver, the Iterated Switched-Mode Receiver(ISMR), which performs very well under the condition I r(T)I <. 25, has been described for the first time. This receiver does not require the long tapped delay line of proposed linear filter receivers and does not require carefully computed tap coefficients in its operation. The ISMR represents an economical and flexible solution of the receiver design problem when intersymbol interference is not too severe.

6. 2 Future Studies
At the conclusion of any theoretical study, the question arises as to whether to pursue the theory further, or to jump into the perilous experimental world for confirmation of the results. The most productive approach seems to be the latter. A carefully controlled implementation of a communication system through the Mimi channel would point out the truly significant problems of underwater communications and perhaps eliminate others from consideration. Although actual implementation of a communication system through the Mimi channel is the next logical step, several theoretical problems are of particular interest. The problem of simultaneous channel measurement to provide a receiver with an up-to-date replica of the noise-free symbol response is important. While transmitted reference techniques suggested in Section 1. 2 can be used, a portion of the transmitted signal energy must be devoted to the reference. One could hope that if the probability of error is sufficiently low, a reference component could be reconstructed from a transmission consisting of only an information component. The development and analysis of such a technique would simplify both transmitter and receiver design.  Another subject for future study would be to consider nonbinary communication systems such as M-ary signalling. By using a larger number of transmitted symbols, the transmitted symbol duration could be lengthened while maintaining the same data rate. Hopefully, the reduced symbol duration in such a system would reduce the effects of intersymbol interference. From a purely theoretical point of view, it would be interesting to consider receiver designs when intersymbol interference is more severe; that is, when M 1. The operating equations for the optimum receiver are known for such problems but offer no hope of evaluation. Development and analysis of a good suboptimum receiver, analogous to the ISMR would provide a reasonable approach to the problem.

REFERENCES
1. William Wesley Peterson, Theodore G. Birdsall and W. C. Fox, "The Theory of Signal Detectability, " IRE Trans. on Information Theory, IT-4, 1954.
2. J. M. Aein and J. C. Hancock, "Reducing the Effects of Intersymbol Interference with Correlation Receivers," IEEE Trans. on Information Theory, July 1963.
3. M. R. Aaron and D.W. Tufts, "Intersymbol Interference and Error Probability,' IEEE Trans. on Information Theory, January 1966.
4. D. C. Coll, A System for the Optimum Utilization of Pulse Communication Channels, Defense Research Telecommunications Establishment Report No. 168, Ottawa, Canada, December 1966.
5. John C. Steinberg and Theodore G. Birdsall, "Underwater Sound Propagation in the Straits of Florida, " Journal of the Acoustic Society of America, 39, pp. 301-315, 1966.
6. M. P. Ristenbatt, et al., Digital Communication Studies, Part I: Comparative Probability of Error and Channel Capacity, Cooley Electronics Laboratory Report No. 133, University of Michigan, Ann Arbor, Michigan, March 1962.
7. R. Price and P. E. Green, "A Communication Technique for Multipath Channels, " Proceedings of the IRE, March 1958.
8. A. Papoulis, The Fourier Integral and Its Applications,
McGraw-Hill Book Co., New York, 1962.
9. C. W. Helstrom, Statistical Theory of Signal Detection, Pergamon Press, New York, 1960.
10. H. Rudin Jr., "Automatic Equalization Using Transversal Filters, " IEEE Spectrum, Vol. 4, No. 1, January 1967, pp. 53-59.
11. S. W. Golomb, et al., Digital Communications with Space Applications, Prentice Hall, Inc., Englewood Cliffs, N. J., 1964.
REFERENCES Cont.
12. U. Grenander, "Stochastic Processes and Statistical
Inference, " Arkiv det Mat., 1, 1950, pp. 195-277.

Descriptors : *UNDERWATER COMMUNICATIONS, INTERFERENCE, DIGITAL SYSTEMS, MULTIPATH TRANSMISSION, BANDWIDTH, ERRORS, PROBABILITY, INFORMATION THEORY.
Subject Categories : Cybernetics Non-radio Communications
Distribution Statement : APPROVED FOR PUBLIC RELEASE

#WA8UNS @WA8UNS #ridgefieldct #Ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut Thomas Q Kimball of Ridgefield, Connecticut wanted to share my father’s first United States Patent 3,611,149 Patent US3611149 ITERATED SWITCHED MODE RECEIVER October 5, 1971

Notice the application date is 1969-06-06 which is about on month before I was born July 4th 1969


United States Patent
3,611,149
Kimball
October 5, 1971

ITERATED SWITCHED MODE RECEIVER 

Abstract
There is disclosed an iterated switched mode receiver which operates on a received distorted serial binary sequence to diminish or eliminate intersymbol interference. The operation of the receiver is predicated upon making two decisions on each symbol. The preliminary or "first guess" decisions on adjacent symbols are used to eliminate the effects of these symbols on the final decision for each symbol. Signal delays are employed so that it is possible to work with the successor digit as well as the predecessor digit. The preliminary decisions on the succeeding and preceding digits are made by threshold circuit having thresholds at zero. The final decision is made by a variable threshold circuit which receives as its inputs outputs representative of the digit immediately preceding, the digit immediately succeeding and the digit to be processed.

Inventors:
Kimball; Christopher V. (Ann Arbor, MI)
Assignee:
The Bottelle Development Corporation a correction would be Assignee is 
(The Battelle Development Corporation Columbus, OH) 
Family ID:
25258014
Appl. No.:
04/830,964
Filed:
June 6, 1969

Current U.S. Class:
375/348
Current CPC Class:
H04L 25/062 (20130101)
Current International Class:
H04L 25/06 (20060101); H04b 001/10 ()
Field of Search:
;324/77H ;325/42,321,322,323,324,473,474,475,47L,477,65 ;333/7T ;235/181

References Cited [Referenced By]

U.S. Patent Documents

August 1966
Linke
August 1966
Ares
December 1969
Schaeffer

Primary Examiner: Griffin; Robert L. 
Assistant Examiner: Mayer; Albert J. 

Claims
I claim: 

1. In a binary communication system, an iterated switched mode receiver for processing received binary digital information from a noisy, band-limited transmission medium to diminish or eliminate intersymbol interference from the kth digit in a serial binary sequence caused by overlapping of its immediate predecessor and its immediate successor digits, said receiver comprising: 
a. first decision means responsive to the binary digital information for providing an output which to a first approximation is representative of the digit immediately succeeding the kth digit in the serial binary sequence, 

b. second decision means for providing an output which to a first approximation is representative of the digit immediately preceding the kth digit in the serial binary sequence, and 

c. third decision means for receiving and comparing the output of said first decision means, a signal corresponding to the kth digit and the output of said second decision means for providing an output representative of the final decision of the kth digit. 

2. An iterated switched mode receiver as recited in claim 1 further comprising a matched filter for receiving the binary digital information and providing said signal corresponding to the kth digit, and means connecting the output of said filter to the inputs of said first and second decision means. 

3. An iterated switched mode receiver as recited in claim 2 first and second delay means connected in series between said filter and said second decision means, said signal corresponding to the kth digit being provided at the output of said first delay means. 

4. An iterated switched mode receiver as recited in claim 2 wherein the transfer function of said filter is related to the Fourier transform of a single symbol. 

5. An iterated switched mode receiver as recited in claim 3 wherein said first and second decision means are Schmitt triggers having thresholds set at zero. 

6. An iterated switched mode receiver as recited in claim 5 wherein said third decision means comprises: 

a. first, second and third Schmitt triggers having their inputs connected to the output of said first delay means, said first Schmitt trigger having a threshold at 2R(T), said second Schmitt trigger having a threshold at zero, and said third Schmitt trigger having a threshold at -2R(T) where R(T) is the autocorrelation function of the noise-free received waveform of a single symbol of value +1, at time T, where T is the duration of the transmitted symbol, 

b. an exclusive OR gate receiving as its inputs the outputs of said first and second decision means, 

c. first and second AND gates, said first AND gate receiving as its inputs the output of said second Schmitt trigger and said exclusive OR gate, and said second AND gate receiving as its input the output of said third Schmitt trigger and also receiving as inhibit inputs the outputs of said first and second decision means, and 

d. an OR gate receiving as its inputs the outputs of said first and second AND gates and of said first Schmitt trigger. 

7. An iterated switched mode receiver as recited in claim 3 wherein said first and second delay means have delays equal to T seconds where T is the duration of a transmitted symbol and further comprising sampling means for sampling the received signal each T seconds. 

8. An iterated switched mode receiver as recited in claim 3 wherein said first and second delay means are digital delay devices. 

9. An iterated switched mode receiver as recited in claim 3 wherein said first and second delay means are analog delay lines. 

10. In a binary communication system, an iterated switched mode receiver for processing received binary digital information from a noisy, band-limited transmission medium to diminish or eliminate intersymbol interference from the kth digit in a serial binary sequence caused by overlapping of its immediate predecessor and its immediate successor digits, said receiver comprising: 

a. filter means for receiving a signal responsive to said digital information and for providing an output that is a predetermined function of said signal; 

b. first decision means responsive to the output of said filter means for providing an output which to a first approximation is representative of the digit immediately succeeding the kth digit; 

c. delay and second decision means responsive to the output of said filter means for providing an output which to a first approximation is representative of the digit immediately preceding the kth digit; 

d. delay means responsive to the output of said filter means for providing an output that is representative of the kth digit, 

e. third decision means responsive to a comparison of the outputs of said first decision means, said delay and second decision means, and said delay means, for providing an output representative of the final decision of the kth digit; 

f. said filter means (a) comprises a matched filter; 

g. said first decision means (b) comprises a first Schmitt trigger having a threshold at zero; 

h. said delay and second decision means (c) comprises said first Schmitt trigger of (g) and first and second delay means connected in series; 

i. said delay means (d) comprises said first Schmitt trigger of (g) and said first delay means of (h) for providing a first output representative of the kth digit, a second Schmitt trigger having a threshold at -2R(T) and third delay means for providing a second output representative of the kth digit, a third Schmitt trigger having a threshold at 2R(T) and fourth delay means for providing a third output representative of the kth digit, where R is the autocorrelation function of the noise-free received waveform of a single symbol of value +1, at time t=T, where T is the duration of the transmitted symbol; and 

j. said third decision means (e) comprises (1) an exclusive OR gate receiving as its inputs the outputs of said first Schmitt trigger and of said second delay means, (2) a first AND gate receiving as its input the output of said third delay means and receiving as inhibit inputs the outputs of said first Schmitt trigger and of said second delay means, (3) a second AND gate receiving as its inputs the outputs of said first delay means and of said exclusive OR gate, and (4) an OR gate receiving as its inputs the outputs of said first and second AND gates and of said fourth delay means.

Description

BACKGROUND OF THE INVENTION 

1. Field of the Invention 
This invention relates generally to binary communication systems, and more particularly to a nonlinear receiver which has as its basic purpose the reconstitution or recovery of binary digital information from a distorted and noisy version of that information. More specifically, this subject invention acts to diminish or eliminate interference for a given digit caused by both its immediate predecessor and its immediate successor in a serial binary sequence. 

2. Description of the Prior Art 

It is well recognized from substantive work that efficient communication of information can take place when the information, Whatever its original form, is converted to a binary presentation. For example, instead of sending a voice signal in the continuous manner in which it was generated by a speaker, various electronic operations can be performed upon the voice signal, whereupon the signal is converted to a sequence of zeros and ones, so that it might appear in coded form as 

10011010110110000101011010110 

A sequence such as that above is called hereinafter a serial binary sequence. 

Let it be supposed that a single serial binary sequence is transmitted using, for example, electrical signals to represent the zeros and ones. This transmitted sequence will then pass through some intervening medium, such as air, wire, coaxial cable, waveguides or the like, before it reaches the receiving station. During the transmission, the physical characteristics of the signals change for two principle reasons. First, there will be unwanted information added to the signal because of other sources in the vicinity of the transmission path. Such additions are referred to as noise. Second, the signal is distorted by the medium. For the example, if the transmission medium or for that matter the transmitting and receiving circuits do not have sufficient bandwidth, the transmitted signal will be spread in time resulting in intersymbol interference in the binary sequence. As a consequence, the signal received at the receiving station does not lend itself to a ready reconstitution of the transmitted signal. More specifically, as received, the signal cannot be immediately decoded into a sequence of zeros and ones. 

The traditional methods of dealing with the intersymbol interference and noise problem are spectrum equalization or transversal equalization. It has been found that the spectrum equalization technique is not really effective in reducing the effects of intersymbol interference in a communication system. In a transversal filter receiver, one must trade noise performance and intersymbol interference performance against each other in order to obtain the best overall system error performance. In other words, the transversal filter receiver while effective in eliminating intersymbol interference in the absence of noise becomes less so as the signal to noise ratio becomes smaller. Often these earlier approaches to the problem require the use of an analog tapped delay line of length equal to several symbol durations and required critical adjustments. 

SUMMARY OF THE INVENTION 

It is therefore an object of the present invention to provide a nonlinear receiver which operates on a received serial binary sequence with intersymbol interference and noise with a low probability of error. 

It is another object of the invention to provide a nonlinear receiver which has as its basic purpose the reconstitution or recovery of binary digital information from a distorted and noisy version of that information. 

It is a further object of the instant invention to provide a receiver in a binary communication system which provides nearly ideal performance with ease of implementation and low system cost. 

According to the present invention, the foregoing and other objects are attained in one embodiment by providing two delay circuits connected in cascade. The delay circuits each provide a time delay equal to one digit interval. There are three outputs from the cascaded delay circuits, one at the input of the first delay circuit, e at the junction of the two delay circuits and one at the output of the second delay circuit. The first output is connected to a first decision circuit having a threshold at zero. The output of the first decision circuit provides a representation to a first approximation of the digit immediately succeeding the digit which is to be processed. The third output is connected to a similar second decision circuit having a threshold at zero. The output of the second decision circuit is representative to a first approximation of the digit immediately preceding the digit to be processed. The digit to be processed is available at the second output. The final decision is made by a variable threshold circuit which receives as its inputs the outputs representative of the digit immediately preceding, the digit immediately succeeding and the digit to be processed. In a second embodiment, the invention is implemented without using any analog delay devices. Instead, digital delay devices can be used in conjunction with conventional logic circuitry. 

BRIEF DESCRIPTION OF THE DRAWINGS 

The specific nature of the invention, as well other objects, aspects, uses and the advantages thereof, will clearly appear from the following description and from the accompanying drawings, in which: 

FIG. 1 is a block diagram illustrating one embodiment of the invention. 

FIG. 2 illustrates the functional properties of the threshold at zero devices shown in FIG. 1. 

FIG. 3 illustrates the functional properties of the variable threshold device shown in FIG. 1. 

FIG. 4 is a logical diagram illustrating one form of variable threshold device that could be used in the system shown in FIG. 1. 

FIG. 5 is a block and logical diagram of another embodiment of the invention which uses digital delay devices. 

DESCRIPTION OF THE PREFERRED EMBODIMENTS 

Referring now to the drawings and more particularly to FIG. 1 thereof, there is shown one embodiment of the iterated switched mode receiver which uses two analog delay lines each of duration equal to that of a transmitted symbol. Let the transmitted symbol have a duration T seconds and let .rho. (t) be the noise-free received waveform of a single symbol of value +1. Let .rho. (.omega.) be the Fourier transform of .rho. (t) and let .rho.* (.omega.) be the complex conjugate of .rho. (.omega.). Furthermore, let R (T) be the autocorrelation function of .rho. (t) evaluated at time t=T. 

Given these conditions, the iterated switched mode receiver shown in FIG. 1 comprises a matched filter 10 which receives the input signal to the receiver. As is well known in the art, a matched filter has a transfer function .rho.* (.omega.) which is the complex conjugate of the transform of a single symbol. The output of the matched filter 10 is connected to a first analog delay line 11 which is in turn connected to a second analog delay line 12. Each of the delay lines 11 and 12 provide a delay of T seconds. Three outputs are available from the circuitry thus far described: one at the input to the first delay line 11 denoted by 13; one at the junction of the delay lines 11 and 13 denoted by 14; and the third at the output of delay line 12 denoted by 15. The signal at output 14 may be represented by the symbol L.sub.k which is the decision variable for the kth symbol. L.sub.k.sub.+1 and L.sub.k.sub.-1 at outputs 13 and 15, respectively, represent the decision variables for the symbols immediately adjacent the kth symbol. Each of the outputs 13, 14, and 15 are connected to respective samplers, 9, 16 and 17. The samplers sample at times O, T, 2T...kT. In the alternative, a single sampler could be provided at the output of matched filter 10 immediately preceding output 13. The outputs of samplers 9 and 17 are connected to the inputs of respective threshold at zero devices 18 and 19. 

FIG. 2 illustrates the operation of the threshold at zero devices 18 and 19. If the input decision variable is greater than or equal to zero, then the preliminary or "first guess" decision output of the threshold at zero device will be a +1. On the other hand, if the input decision variable is less than zero, then the "first guess" decision output of the device will be -1. The threshold at zero decision devices are realized in terms of the conventional Schmitt trigger circuit. See, for example, Millman and Taub, Pulse, Digital and Switching Waveforms, McGraw-Hill, 1965, at pages 389 to 394. Thus, a "threshold at B" circuit is simply a Schmitt trigger with trigger levels set to B. That is, the Schmitt trigger has a logical one output if the input level is greater than or equal to B, and gives a logical zero output otherwise. The threshold at zero decision device is therefore simply a Schmitt trigger with a zero trigger level. 

Returning now to FIG. 1, the output of the sampler 16 is connected to one input of a variable threshold decision device 20. Variable threshold decision device 20 also receives as inputs the outputs of threshold at zero devices 18 and 19. Thus, the variable threshold device receives as inputs L.sub.k, d.sup.0.sub.k.sub.+1, and d.sup.0.sub.k.sub.-1. 

FIG. 3 shows the operation of the variable threshold device 20. For example, if the preliminary or "first guess" decisions for each of the adjacent symbols is +1 and the decision variable for the kth symbol is greater than or equal to 2R(T) then the final decision on the kth symbol is +1. The other possible combinations will be apparent from an examination of the table in FIG. 3. The variable threshold decision device can be easily implemented using Schmitt triggers and digital logic. 

One possible implementation of the variable threshold decision device is illustrated in FIG. 4. In this implementation there are three Schmitt triggers 21, 22 and 23 all having a common input denoted by L.sub.k. Schmitt trigger 21 has a threshold at 2R(T), while Schmitt triggers 22 and 23 have threshold levels at zero and -2R(T), respectively. The outputs of each of the Schmitt triggers 21, 22 and 23 are coupled to respective AND gates 24, 25 and 26. AND gate 24 also receives as inputs the outputs of the threshold at zero decision devices 18 and 19 shown in FIG. 1. The outputs of the decision devices 18 and 19 are also connected to the inhibit inputs of AND gate 26. Finally, these same outputs are combined in a modulo 2 adder or exclusive OR gate 27, the output of which is connected as a second input to AND gate 25. The outputs of AND gates 24, 25 and 26 are all combined in OR gate 28 to provide the final decision on the kth symbol. 

Referring again to FIG. 3, it will be seen that the implementation of the variable threshold decision device shown in FIG. 4 provides the proper functions. For example, considering the case where the output of threshold at zero device 18 is +1, the output of threshold at zero device 19 is -1, and L.sub.k is greater than or equal to 0, it will be seen that the output of AND gate 25 will be +1 since the exclusive OR gate 27 will produce a +1 output whenever it has only one +1 input. If the outputs of both of the thresholded zero devices 18 and 19 are -1 and L.sub.k is greater than or equal to -2R(T), then AND gate 26 will produce a +1 output. The remaining examples will be apparent on examination of the table in FIG. 3. 

In an alternative embodiment, the iterated switched mode receiver can be implemented without using any analog delay devices. Instead, digital delay devices such as, for example, flip-flops can be used in conjunction with conventional logic devices. In FIG. 5, the input signal is coupled to a matched filter 29 which is like the matched filter 10 of FIG. 1. The output of matched filter 29 is connected to the inputs of three Schmitt triggers 30, 31 and 32. Schmitt triggers 30 and 31 have thresholds set at +2R(T) and -2R(T), respectively, and Schmitt trigger 32 has its threshold set at zero. The output of Schmitt trigger 32 is connected to the input of a first digital delay device 33 which in turn has its output connected to the input of a second digital delay device 34. The digital delay devices 33 and 34 may be, for example, flip-flops which are connected as shift register stages. As such, device 33 would be set by an output from Schmitt trigger 32 and have its contents shifted out with the next clock pulse (not shown) synchronized with the sampling gate intervals (again not shown). The delay device 34 would be set by an output from device 33 and in a like manner would have its contents shifted out with the next clock pulse. Similar delay devices 35 and 36 are connected to the outputs of Schmitt triggers 30 and 31, respectively. 

The output of Schmitt trigger 32 and the output of digital delay device 34 are connected to the inputs of modulo 2 adder or exclusive OR gate 37. The outputs of digital delay devices 33 and 36 and the output of exclusive OR gate 37 are connected as inputs to AND gate 38. AND gate 39 also receives as its input the output of digital delay device 36. The output of Schmitt trigger 32 and the output of digital delay device 34 are connected to the INHIBIT inputs of AND gate 39. The output of digital delay device 35 and the outputs of AND gates 38 and 39 are combined in OR gate 40 to provide the final decision output on the kth symbol. 

It will be apparent that the embodiments shown are only exemplary and that various modifications can be made in construction and arrangement within the scope of the invention as defined in the appended claims. 


References Cited [Referenced By] 
PAT. NO.  Title
1
2
3
4
5
6
7
8
9
10
11

#WA8UNS @WA8UNS #ridgefieldct #Ridgefield @ridgefield  in #FairfieldCounty #CT  Thomas Q Kimball of Ridgefield, Connecticut wanted to share Some 42 years later I can now see and read some of my own father’s work. This took about 3 years from my first FOIA request 13-F-1279 On 20 August 2013 after spotting my father's work Kimball C.V. Acoustic Communication Studies on a online Journal of Defense Research Cumulative Index, 1969-1978. 


Then to ONR FOIA 16-061 received scanned pdf on July 20th 2016

Though I was a young boy at the time while we had lived in Miami, Florida from 1971-1979. Here is a piece of his work called 
Acoustic Communication Studies (U) An experimental study of techniques for Submarine to Submarine Communications Systems. 
Contract Number N00014-73-C-0593 Technical Report July 1971 June 1974  Report Date September 1975 ARPA Advanced Research Projects Agency Office Of Naval Research Code 222. Supplementary Notes: To be published in the Journal Of Defense Research Series B Tactical Warfare, September 1975 Performing Organization Ocean Engineering Division RSMAS Rosenstiel School of Marine and Atmospheric Science University Of Miami UM-RSMAS 75034 Palisades Geophysical Institute Miami Florida

By this above Table 1. Summary of fixed-site communications experiments. You can tell by Experiment M1 and appears year is 1968 my father had started working on this when still at Cooley Electronics Laboratory University of Michigan. The above in table finished with the Experiment M6C year 1973


The little guy in the crib is Thomas Q Kimball WA8UNS

My father was in Signal Officer Basic Course, Ft Gordon June through August 1969 but came back to Ann Arbor, Michigan to see my birth July 4th 1969. At the The University of Michigan Hospital  Ann Arbor, Michigan. From 1969 until 1971 my father had to do his Army two-year active duty US Army Signal Corps Officer with the US Army Security Agency Support Group out of Ft Meade, Md. We had a TDY at Ft Hood, TX  December 1969 through May 1970 for MASSTER US Army Project Mobile Army Sensor System Test Evaluation and Review Surveillance, Target Acquisition and Night Observation STANO. National Security Agency NSA R Group - Research and Engineering 1970-1971 after that in 1971 we would move to Miami, Florida. 



Thomas with his father somewhere in the Florida Everglades  Circa 1970’s after 1971.

My father who was WB4WZR in Miami then 1971-1979 And WA8UNS from 1966-1971
 Where it all started 69-71 Call sign WA8UNS at our home in Bowie, Md United States  Notice the HF Antenna in the back ground. 


Thomas Q Kimball WA8UNS from Ridgefield, Connecticut and my father Operating Special Station February 4th - 6th 2013

Father and son Operating Amateur Radio Ham Radio at AMC Appalachian Mountain Club Northwest Camp. northwest slope of Bear Mountain in Salisbury, CT.  My Mom did the role of professional Photographer. Thanks :)

I have taken time to re-write some of my father’s work below are samples and or parts of his work. Please note some of the mathematics might be off in my re-write as some of it hard to see. The complete work can be found here: http://www.dtic.mil/docs/citations/ADC003594 so it would be picked up by search engines such as google. I am sharing his work for educational purposes.




An experiment study of coherent, matched filter techniques for  submarine-to-submarine communication was conducted, matched filter techniques offer three advantages over existing systems. First, coherent integration allows useful system operation at signal-to-noise ratios significantly below 0 db. Incoherent systems experience a threshold at a 0 db signal-to-noise ratio, which causes system performance to deteriorate rapidly. Second, filtering of the received information symbol with a filter matched to the received symbol waveform reduces the effects of both noise and multipath. Finally, these techniques are compatible with a wideband, randomized transmission format, which reduces the detectability of the signal by unintended receivers. The research program was conducted in two stages. The first stage evaluated communication system performance over 7- and 42- nmi fixed-site ranges. Over 4,000 hours of experimental data were obtained and analyzed to ensure the statistical significance of the measurements. Results from these data showed that reliable communication could be obtained with signal-to-noise ratios below 0 db. A typical experimental system (M6B) transmitted 0.625 bit/sec in a 100-hz band centered on 420 hz. Over a 42-nmi patch this system yielded a bit error probability of 0.01 at an input signal-to-noise ratio of -9 db. Such performance is within 6 db of that obtainable with the optimum receiver operating though a linear time invariant channel with added white Gaussian noise. To determine the applicability of the fixed-site results to the submarine-to-submarine communication problem the second stage of the program investigated the space-time stability of the acoustic medium with a towed source. An experiment was conducted in the deep ocean off Eleuthera, B.I at ranges from 0 to 400 nmi. This experiment indicated only a 10 percent decorrelation  in the channel from one 30-sec interval to the next. Consequently the coherent, matched filter techniques evaluated over the fixed-site ranges are applicable to practical problems involving moving platforms. Based on the results of the experimental program development of a practical submarine-to-submarine communication system using coherent matched filter techniques is proposed. A particular implementation (M7) incorporating a randomized burst-type transmission for detection resistance is suggested as a basis for future work. 

1 Introduction:
Underwater acoustic communications systems based on coherent matched filter techniques have been studied coherent matched filter techniques have been studied experimentally. Although the specific goal of the research was tactical submarine to submarine communications systems, the results are applicable to other situations. This paper describes extensive fixed-site communication experiments and an important transmission measurements that encourage the immediate consideration of these techniques for submarine communication systems. 

Coherent, matched-filter techniques offer three distinct advantages for submarine communication systems. First coherent integration allows satisfactory operation at low signal-to-noise ratios without the threshold effect that is common to incoherent systems. Second, matched-filter operation reduces the effects of both noise and multipath under varying propagation conditions. And finally these techniques are compatible with a randomized transmission format that reduces the detectability of the communication signal. 

The processing techniques employed in the research are based on well established theory. The acoustic medium is measured to approximate a linear, time-invariant channel with added white Gaussian noise. For such a channel, the optimum receiver is composed of a filter matched to the received signal, following by the threshold device.The matched filter can also be shown to reduce intersymbol interference caused by multipath.

Because the physical channel is distinctly time-varying the received symbol waveform must be continually measured to maintain the required match between the filter and the symbol waveform. This measurement is made possibly including a known probe component in the transmission in addition to the unknown information component. Thurs the communication systems described here perform dual roles channel measurement and information transmission. 

The second stage of the experimental program was to determine the applicability if the fixed-site results to the submarine communication problem. For such an application to be possible, the acoustic medium must be stable in space as well as time. That is the probe measurement  of the channel must remain valid under spatial displacement of the submarine platform consequently a careful measurement of the spatial stability was made as described in Section V. 

The union of the results from the fixed-site communication experiments and the spatial-stability measurements solely indicates the feasibility of coherent matched-filter techniques for the submarine communication systems.This conclusions and others are presented in section VI. An application of these techniques in conjunction with a randomized transmission format is also given. 

II. Transmission  Format
Because of the dual nature of the transmission and the implementation of the receiver processing the signals transmitted by the communication systems have a complicated format. One part of the signal the probe component allows measurements of the channel the other the information component contains the information. Subsequent parts of this section describe these components in detail and explain there choose of transmission format. Section III on the receiver processing completes the explanation. The probe and information components are transmitted interleaved  in time (time multiplexed) as described in section IIb

A.  Basic Signal Element The Digit:
Both components of the transmission are composed of a succession of biphase modulated elements called digits The simplest example of a digit waveform is a rectangular carrier pulse.The probe and information components consist of modulated digits in a prescribed (or in the case of the information component almost prescribed) earlier. In the subsequent discussion no conflict will arise if the digit waveform is assumed to be a rectangular carrier pulse although in practice some amount of band spreading of the digit is desirable as suggested below. For a rectangular carrier pulse the pulse duration and bandwidth are inversely related: that is, once the duration is specified, the bandwidth is also fixed.


B. Probe Component
The probe component of the transmission allows the receiver to measure the channel digit response. Because the information symbols are composed of the combinations of the digits, a filter matched to the symbols can be formed from the digit response. The probe component must be constant and known to the receiver if this measurement is to be successful. 


C. Information Component
The information component can be formed in one of three ways: (1) biphase modulation of single transmitted digits: (2) biphase modulation of groups of digits, where the intragroup structure is constant: or (3) variable symbol modulation in which biphase modulation of groups of digits, where the intragroup structure varies from on symbol to the next is carried out. 

In the subsequent discussion, the difference between a digit-described previously-and a symbol is important. A symbol is a digit or groups of digits used to carry a single bit of information. The objective of the receiver is to determine symbol values, not digit values, thus the difference between the two methods of forming the information components lies in the structure of the symbol waveform. 

1. Single Digit Symbols 
The simplest construction of the information component assigns a single digit to each symbol. A digit transmitted at 0 phase represents a binary one; a digit transmitted at 180-deg phase represents a binary-minus one. This technique was used in the M1,M2, M3 and M4 systems. 

2. Multiple Digit Symbols
If each information symbol is composed of only one digit as described above then potential tradeoff opportunities for the system design are eliminated.


3. Variable Symbol Modulation
If more than one digit is contained in each symbol as described above, the opportunity to alter the symbol composition from one time interval to the next arises.

D. Multiplexing of Probe And Information Components
The transmission in each of the matched-filter communication systems consists of a multiplex of the probe and information components. In choosing the multiplexing technique the particular purpose of the probe component must be considered. For example frequency multiplexing would be inappropriate in the acoustic medium because the digit response measured in one frequency band would not be valid in another frequency band. 

III. Receiver Processing
The receiver in the M5 and M6 communication systems performs a dual role. The first part of this dual role is to measure the existing channel digit response from the probe component of the transmission. 




A. Preliminary Processing
Signals from the receiver hydrophone are transmitted though linear, fixed-gained amplifiers to the processor, the gains of these amplifiers being selected so that no clipping occurs during normal operations. 

B. Probe Processing
The primary objective of the probe processing is to determine the channel digit response. A secondary but important , objective of the probe processing is to measure the basic transmission characteristics of the medium to aid in evaluation and understanding of the system performance. 

1. Channel Digit Response Measurements
As mentioned above, the primary objective of the probe processing is to derive the approximate channel digit response p(t) Let p (k,i) be the sampled data representation of p(t) obtained in the kth measurement interval. 


2. Measurement of Signal and Noise Powers
The wideband signal and noise powers, SP and NP are measured to allow evaluation of the system performance.

C. Information Component Processing 
The objective of the information component processing is to make correct decisions on the transmitted symbol values. These decisions can be scored against known answers in the case of a periodic transmission. For demonstration purposes the received values can be printed as characters on a teletype. 

1. Matched-Filter Operation
The first step in the processing of the kth information component is to form a coherent average a,(k,i) of the information component:

2. Decision Process
To determine the symbol values a zero threshold is applied to the symbol matched-filter outputs L(k,i).

3. Scoring of Receiver Decisions
To evaluate the system error performance the receiver decisions d(i) are scored against know correct values. This can be done as long as the symbol values in the information component are known as they are in the case of periodic transmission.

D. Synchronization
In the preceding discussion synchronization  between the receiver and received signal has been assumed. When a periodic transmission is sent the probe and information components are identical and no synchronization is necessary. 

E. Implementation 
The receiver processing for both communications systems was performed by small general purpose digital computers frequently called minicomputers. The M5 systems were implemented on a Digital Equipment Corporation LINC-8 computer with a 4,096-word (12 bits/word) memory. The M6 systems were implemented on a DEC PDP-8E system with an 8,192 word (12 bits/word) memory. 


CEL   Technical Memorandum No. 104
03604-1-M
OPERATOR'S MANUAL
for the
M4 COMMUNICATIONS EXPERIMENT
by
David Jaarsma
COOLEY ELECTRONICS LABORATORY
Department of Electrical Engineering
The University of Michigan
Ann Arbor, Michigan
Contract No. N00014-67-A-0181-0032
Office of Naval Research (Code 468)
Department of the Navy
Washington, D. C. 20360
August 1970

I. INTRODUCTION
The M4 Communication System is a complete revision of the
M3 Communication System as constructed by C.V. Kimball in
June 1969.

Some photos diagrams from the above work as to computer and system set up which is interesting to me as you can see a Receiving and a Hydrophone Line


Photos of computers below:
Receiving Hydrophone Line 100 Hz Bandpass Filter etc.

PDP-8 - Wikipedia, the free encyclopedia

   DIGITAL EQUIPMENT CORPORATION PDP 8/E 
FIELD-8 computer Field-8/E System 1 with what looks like a General Radio 1161-A Coherent Decade Frequency Synthesizer ontop of the FIELD-8 computer Field-8/E System 1







LINC-8 - Wikipedia, the free encyclopedia


( Pictured ) The LINC-8 contained one PDP-8 CPU and one LINC  The LINC (Laboratory INstrument Computer)  CPU, partially emulated by the PDP-8 LINC-8 was the name of a minicomputer manufactured by Digital Equipment Corporation between 1966 and 1969. ( Pictured ) The Teletype Corporation ASR 33 Teletype 


The Digital Equipment Corporation DEC PDP-8e PDP-8m Small Computer Handbook with Digital Equipment Corporation, PDP-11 Processor Handbook
IV. Experimental Program
Five long-term experiments (M5A, M5B, M6A, M6B, and M6C) were performed between fixed sites in the Straits of Florida to evaluate the effectiveness of coherent integration/matched-filter techniques.

A. Differences Among Experiments
In each of the five experiments the transmission was generated by the source off Fowey Rocks Light. During the M5 experiment signals were received at a hydrophone located 7 nmi from the Fowey Rocks source while in the M6 experiment signals were received at the Bimini hydrophone 42 nmi from the source.

B. Experimental Results
The five experiments yielded data on both acoustic transmission conditions and system error performance. In this section only measurements that bear on the evaluation of system error performance or on future applications on the communication system are discussed. 


1. Signal-to-Noise Ratio Histograms
To interpret the communication performance data, an understanding of the signal and noise environment of each experiment is necessary.


2. Communication System Performance
Evaluation of communication system performance is a difficult problem when one is confronted with a varying conditions of the acoustic medium. 


3. Channel Stability Measurements
The utility of the match-filter technique studied here is highly dependent on the stability of the medium. If the acoustic channel changes significantly from the time of the probe measurement to the time of the information component processing then the filter will not be properly matched and an increase in errors can be expected. 

V. Spatial Stability Measurements
The preceding sections described the operation and performance of an underwater acoustic communication system operating between two fixed points. In a practical submarine communication system one or both ends of the acoustic channel is in motion so a spatial variations  as well as temporal variations are important. This sections describes two measurements of the spatial stability of the medium and provides the foundation for the extension of the fixed-site communication techniques previously discussed to the submarine communication problem. 


The fixed-site experiments have shown the temporal stability of the medium to be sufficient to allow integration times of the order of one minute. From a purely geometric point of view the medium should also be stable under spatial displacements that are common to submarine platforms. For example a submarine on a 10-knot zero Doppler track at a range of 100 nmi subtends less than 0.1 deg of arc in one minute. The wideband characteristics of the acoustic channel would not be expected to change significantly under such a displacement. Nevertheless careful measurements have been made to validate this intuitive understanding.


A. Coherent Cross Correlation without Coherent Integration
In this measurement technique the spatial stability of the medium was measured in terms of normalized correlation coefficients p1(i) analogous to the correlation coefficient p(k) studied in the M5 and M6 experiments. Because of the presence of the Doppler effect however the definition had to be modified slightly. The transmission was a 15-digit pseudorandom sequence similar to that of the M5A,M5B and M6A experiments. 




The preliminary spatial stability measurements were conducted with a towed HX90 source in the Straits of Florida during September 1973. Figure 14 depicts the vessel track during these experiments. The source was towed at approximately 200-ft depth with vessel speeds of 2.5, 5, and 10 knots. Signals from the source were received at a hydrophone approximately 7 mmi from the Fowey Rocks Light and were sent via cables to the laboratory on shore. 

B. Coherent Cross Correlation with Coherent Integration
After the preliminary spatial stability measurements in September 1973 development of a measurement technique including coherent ingrain was initiated. The requirement for coherent integration was based on two considerations. First the September 1973 experiments showed that noise and surface modulation precluded measurement of the spatial stability when no coherent integration was used and second an opportunity to study spatial stability at long ranges in the deep ocean was available. The input signal-to-noise ratio at these ranges required coherent integration to obtain adequate representation of the signal. The resulting measurement technique which employs coherent cross correlation with coherent integration is described below. Because of the need to perform coherent integration as well as to accommodate Doppler effects fast Fourier transform techniques (FFT) were employed.
1. Operation at Zero Doppler
To understand the operation of the operation of the measurement technique first consider its operation with zero Doppler. Because the transform interval contains nearly 22 sequence periods every 22nd transform spectral line from the carrier will contain signal energy. The intervening 21 transform lines will contain only noise energy. Consequently a processing gain of 22 (13.4 db) can be achieved by considering only every 22nd transform spectral line about the carrier. 

2. Operation with Nonzero Doppler
Measurement of the correlation coefficient p2(k) and the input and output signal-to-noise ratios is not significantly more difficult when the Doppler is nonzero. Let f be the Doppler-shifter carrier frequency

If the difference between f and the receiver center frequency f is small then the effect of Doppler on the received signal is approximately a frequency translation. Such a frequency translation acts as a fixed offset between the zero-Doppler location of the signal spectral lines and the actual received spectral lines.


3. Experimental Results
During January 1974 the HX90 acoustic source was towed in the deep ocean between Eleuthera and Bermuda. The approximate vessel track relative to the hydrophone is shown in Fig 18. Signals from the source were received at a fixed hydrophone and processed with the the coherent integration technique described above. The ranges of the experiment varied from 0 to 400 mmi with most of the experiment being conducted at ranges between 300 and 400 mmi. During the experiment the vessel speed was maintained at approximately 6 knots.

VI. Future Applications and Conclusions
The effectiveness of coherent matched-filter techniques was demonstrated in fixed-site experiments in the Straits of Florida. The application of coherent integration over time intervals of the order of one minute yield satisfactory operation at input signal-to-noise ratios below 0 db. By matched filtering of the received signal the effects of selective fading and intersymbol interference due to multipath were reduced. Massive amounts of data (over 4,000 hours) on system performance add significance to the results obtained. 

To apply coherent matched-filter techniques to the submarine communication problem an understanding of the medium’s spatial as well as temporal stability is required. A ten-day experiment in the Atlantic between Eleuthera and Bermuda with a towed source and a fixed hydrophone was conducted to measure spatial stability.The results from this experiment indicated the presence of sufficient spatial stability over intervals of at least 30 sec at six knots at ranges from 0 to 400 nmi.

The combination of fixed-site communication system results and the spatial stability measurements establishes the feasibility of coherent matched-filter techniques for submarine communications. Advantages to be gained from these techniques include reliable operation at low signal-to-noise ratios and under varying propagation conditions. Further randomized transmission formats can be employed to reduce the detectability of the communication signal. Because the technology required to implement coherent matched-filter techniques is readily available their application to submarine communications should be initiated. 


1. Subsidiary Conclusions
The experimental program yield several secondary results that should be considered in subsequent submarine communication system design.

First the acoustic medium exhibits significant variance in input signal-to-noise ratio SNR even under fixed-site conditions. Standard deviations of SNR of the order of 5 db can generally be expected. These variations require that any reliable communication system be able to operate successfully over a wide range of input signal-to-noise ratios. Coherent matched-filter systems satisfy this requirement more closely than the incoherent systems currently in use. 

Second impulsive noise must be accounted for in any system in which low PE 0.001 bit error probabilities are required. The presence of infrequent high-energy noise pulses can limit the error probability to a fixed level independent of the average input signal-to-noise ratio. Soft limiting of the receiver input in conjunction with error-correcting codes can be used to overcome this limitation. 


B. Suggested Application
The M5 and M6 communication systems were designed specifically for the evaluation of coherent matched-filter techniques. Consequently, their structures lack many features required of a practical submarine communication system. For example, the transmission in the M5 and M6 systems is continuous and synchronization is performed by the operator. Neither of these characteristics is acceptable in practice. The purpose of this section is to suggest one realization of a coherent, matched-filter  communications system that is suitable for operational use. Only the structure of the transmission and the expected performance characteristics are given here. The details of the receiver processing and implementation will be available in the future. 


The M7 system described below has been designed to provide an application of coherent matched-filter techniques that satisfy the requirements previously stated. Specifically the M7 system utilizes a burst type of transmission with a randomized format. The structure of the transmission is based entirely on an arbitrary random binary sequence that can be changed on a daily basis if desired. The only constraint on the sequence is that it must be know to both the transmitter and receiver and have the same statistical properties as other random sequences. 

In the M7 system the probe and information components are phase multiplexed instead of time multiplexed as in the M5 and M6 systems. Let a(t) be a low-pass digit of duration T and let f be the carrier frequency, then the M7 transmission is given by ____. 

The first term in the sum is the probe component and the second is the information component. The coefficients __ are derived from a random binary sequence q(i) and the information component as indicated below. 

Let __be a random binary sequence of length 2k The coefficients for the probe component qr(i) are simply the q(i)s of even index.


Assume that K information bits e(i) are to be transmitted. Further assume that Kb is a factor of Ki so that K=Kb Ks for some integer K Then the coefficients for the information component are given by

Since both coefficients q (i) and q (i)  are derived from a random sequence q(i) the transmission m(t) can be expected to be free from periodicities or strong spectral components. If the input signal-to-noise ratio of an intercept receiver is below 0 db the detectability of the M7 transmission will be very low. If the input signal-to-ratio of the intercept receiver is above 0 db conventional power measurements techniques are applicable. Consequently the M7 technique (and any other) can be considered detection resistant only if the intercept receiver in denied an adequate  signal-to-noise ratio that is beyond a certain range. 

To provide an illustration of the performance to be expected of the M7 system a specific practical example is given: Assume that the system bandwidth is 100 hz and that the transmission duration is limited to 40 sec. Let n(t) be 10-m sec rectangular pulse, so that the spectrum of the n(t) fills the system bandwidth. Then K, equals 4,000. Table 5 gives the system performance for several choices of K. The column marked “minimum operating SNR” gives the input signal-to-noise ratio expected to yield a bit probability of error of 0.001. This signal-to-noise ratio is obtained by taking the theoretical signal-to-noise ratio required to obtain such performance and then adding a +6 db differential to account for non-idealities. Note the low signal-to-noise ratios for which the 0.001 error probability is expected. 
-----------------------


Under Acknowledgements he mentions Navy CDR Don Koehler and company of the US Naval Facility Eleuthera during the January 1974 experiments.

Special appreciation is due to Dr. Chester A. Jacewitz, Mr. John J Shearer and Ms. Mary Forlenza for their contributions to the research program

And References 
1) C.V. Kimball Intersymbol interference in binary communication systems technical report 195 Cooley Electronics Laboratory University of Michigan August 1968
2) C.V. Kimball A MIMI Communication Experiment technical report 197 Cooley Electronics Laboratory University of Michigan 
3) David Jaarsma Experimental Research in Binary Communications using the Miami 42 mile Underwater Acoustic Channel technical report 207
4) John C. Steinberg and Ted G. Birdsall Underwater Sound Propagation in the Straits of Florida 1966.
* My father is mentioned in the piece of work under acknowledgments C.V. Kimball on the computer analysis techniques. 




Some of the Distribution List to my father’s  Acoustic Communication Studies (U) An experimental study of techniques for Submarine to Submarine Communications Systems. Contract Number N00014-73-C-0593. I would like to think that maybe his Interim Invention Statement US Navy N00014-75-C-0593 might have had the same Distribution List is in hopes that one of these other agencies within the The Department of The Navy might still have a copy. 

Advanced Research Projects Agency
1400 Wilson Blvd.
Arlington, Virginia 33309
Attn: Dr. John Richard Seesholtz
Dr. R Cook

Office of Naval Research (Code 222)
800 N. Quincy St.
Arlington, Virginia 22217
Att: Dr. Alan O. Sykes

Director
Naval Research Laboratory
Washington, D.C 20390
Att: Dr. William Hahn
Mr. Caldwell McCoy
Technical Information Division

Commander
Naval Ordnance Laboratory
Acoustics Division
White Oak, Silver Spring, Maryland 20907
Attn: Dr. Zaka Slawsky

Commander
Naval Undersea Center
San Diego, California 92132
Attn: Mr. Darrell Marsh
Dr. Harper Whitehouse

Commanding Officer & Director
Naval Underwater Systems Center
Fort Trumbull
New London, Connecticut 06321
Attn: Dr. Alan V. Ellinthorpe
Dr. Albert H Nuttall
Dr. Dan Viccione

Commander
Naval Air Development Center
Johnsville, Warminster, Pennsylvania 18974

Commanding Officer
Naval Ship Research & Development Center
Washington, D.C 20034

NISC Naval Intelligence Support Center
4301 Suitland Road
Washington, D.C. 20390
Attn : Johann Martinek
Mr. E. Bisset

Commander
Naval Ordnance Systems Command
Code ORD-03C
Navy Department
Washington, D.C. 20360

Commander
Naval Sea Systems Command
Washington, D.C 20360
Attn: Mr. Carey D. Smith
Mrs. Dolly Hoffman 

Commander
Naval Undersea Research & Development Center
3202 E Foothill Blvd.
Pasadena, California 91107

Naval Electronics Systems Command
Washington, D.C. 20360
Attn: Mr. M. Parker
Mr. I. Smitten

Naval Electronics Systems Command
Submarine Integration Divison 
PME 117-23
Washington, D.C. 20360
Attn: Mr. Weinberger

Chief of Naval Operations
801 N. Randolph Street
Arlington, Virginia 22203
Attn: Code OP-095C

Defense Documentation Center
Cameron Station
Alexandria, Virginia 22314

Dr. Harry Sonnemann
Office of the Assistant Secretary of the Navy
(Research & Development)
Room 4D745, Pentagon
Washington, DC 20350



UPDATE :
To me and my father's disappointment as we just learned from August 30th 2016 The Office of Naval Research FOIA office that ONR The Department of The Navy had destroyed my father's Interim Invention Statement US Navy N00014-75-C-0593. 

The next step being his (M7) Interim Invention Statement US Navy N00014-75-C-0593 Based on the results of the experimental program development of a practical submarine-to-submarine communication system using coherent matched filter techniques is proposed. A particular implementation (M7) incorporating a randomized burst-type transmission for detection resistance is suggested as a basis for future work. 

So why would ONR The Department of The Navy destroy an Invention as many years of work went into this ?  So in a letter from ONR FOIA dated August 30th 2016 According to our records the contract files destroyed on November 14, 1984 pursuant to the Department of the Navy Management Program Manual (SECNAV 5212.5B)

My father is in his 70’s now and it would be great if he is able to see his work again that he did for The Department of The Navy Office Of Naval Research in which was funded by ARPA (Advanced Research Projects Agency) Defense Advanced Research Projects Agency (DARPA)

Defense Technical Information Center
Accession Number : ADC003594
Title :   Acoustic Communication Studies
Descriptive Note : Technical rept. Jul 1971-Jun 1974
Corporate Author : ROSENSTIEL SCHOOL OF MARINE AND ATMOSPHERIC SCIENCE MIAMI FL


Report Date : Sep 1975
Pagination or Media Count : 47
Abstract : An experimental study of techniques for submarine to submarine communication was conducted. Based on the results of the experimental program, a practical submarine to submarine communication system is proposed. A particular implementation (M7) is suggested as a basis for future work.

Descriptors :   *ACOUSTIC COMMUNICATIONS, *UNDERWATER COMMUNICATIONS, SECURE COMMUNICATIONS, SIGNAL PROCESSING, SIGNAL TO NOISE RATIO, SUBMARINES, TOWED BODIES, UNDERWATER TO UNDERWATER

Subject Categories : Acoustic Detection and Detectors
      Acoustics
      Non-radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE



I had thought I had liked the above film about The 70 Years of Innovation: ONR (Office of Naval Research) Reaches a Milestone as Rear Adm. Mat Winter, Chief Of Naval Research and Dr. Lawrence Schuette director of the Office of Naval Research discusses in this youtube video But have changed my feelings about it after this. My own father had spent many years doing contract work for ONR. 65-79 minus his two years Active duty Army. But to me and my father's disappointment as we just leaned from today August 30th 2016 The Office of Naval Research FOIA office that ONR The Department of The Navy had destroyed my father's Interim Invention Statement US Navy N00014-75-C-0593. So why would ONR (Office of Naval Research) The Department of The Navy destroy an Invention as many years of work went into this ?  So in a letter from ONR FOIA dated August 30th 2016 According to our records the contract files destroyed on November 14, 1984 pursuant to the Department of the Navy Management Program Manual (SECNAV 5212.5B)

I personally in my opinion would not have enjoyed hearing this if I was one of those best and brightest scientist ever as mentioned in the ONR (Office of Naval Research) video The 70 Years of Innovation: ONR (Office of Naval Research) Reaches a Milestone after many years of time effort and hours put into contract work and or inventions just to have them sent you a letter reading According to our records the contract files destroyed on November 14, 1984 pursuant to the Department of the Navy Management Program Manual (SECNAV 5212.5B)

 So how could my first ONR FOIA request for N00014-73-C-0593 be found ? 
Is it because it was a Office of Naval Research Contract but it was funded by ARPA (Advanced Research Projects Agency) Defense Advanced Research Projects Agency (DARPA)
  This was to be the next step in his of his Acoustic Communication Studies (U) An experimental study of techniques for Submarine to Submarine Communications Systems. Contract Number N00014-73-C-0593 as seen here: http://www.dtic.mil/docs/citations/ADC003594

The next step being his (M7) Interim Invention Statement US Navy N00014-75-C-0593 Based on the results of the experimental program development of a practical submarine-to-submarine communication system using coherent matched filter techniques is proposed. A particular implementation (M7) incorporating a randomized burst-type transmission for detection resistance is suggested as a basis for future work. 

Thomas Q Kimball then at home in 1971-1979 at 8441 SW 142nd Street Miami, Florida 33158 

Thomas Q Kimball with the SWSC Sheeler Winton Swim Club 1970's

WA8UNS Thomas Q Kimball of Ridgefield, Connecticut  was a member of  The Sheeler Winton Swim Club in Miami, Florida 1971-1979 As it was truly a great place to swim.


Many thanks to Jim Donovan CAPT USN (Ret) Director IUSSCAA and the group for allowing me to become a member of the IUSS CAESAR Alumni Association, Integrated Undersea Surveillance System Caesar Alumni Association.

The Third Battle Innovation in the U.S. Navy's Silent Cold War Struggle with Soviet Submarines By Owen R. Cole Jr. 


Please click here to see:

The US Naval Facility Eleuthera Bahamas is mentioned in The Third Battle Innovation in the U.S. Navy's Silent Cold War Struggle with Soviet Submarines


#WA8UNS @WA8UNS #ridgefieldct #Ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut Thomas Q Kimball of Ridgefield, Connecticut is the monitor for my US Naval Facility Eleuthera Bahamas Facebook Group in which is a closed group. As I only approve people are former employees and their dependents family member I approve the request to join. I request if you would like to join please message me as when you where there and a photo if possible. 


The picture collection of US Naval Facility Eleuthera, Bahamas, NAVFAC Eleuthera 1970's Pictures taken by father while working for the Office Of Naval Research ONR.

Please see and read pages 90-97 of the Papers in Australian Maritime Affairs | Royal Australian Navy Papers in Australian Maritime Affairs No. 21. Australian Maritime Issues 2007 - SPC-A Annual






Nicely written as to my 8 1/2 years living in Miami, Florida between 1971-1979 before moving to Connecticut in 1979.

The below information is 


And
Please see pdf link on Using the Ocean to Hunt Soviet Submarines, 1950-1961 History – The American Sound Surveillance System: Using the Ocean to Hunt Soviet Submarines, 1950-1961 Volume 5 Number 2. The American Sound Surveillance System:  Gary E. Weir,. U.S. Naval Historical Center;
The below mentions two names of folks that my father had worked with from being a student of Theodore Birdsall, at Michigan’s Cooley Electronics Laboratory and with working with John Steinberg

Steinberg worked for seven years on Project Jezebel, the low frequency acoustic research that made the Sound Surveillance System [SOSUS] possible.

When he left Bell Labs for retirement and a research post at the University of Miami’s facility on Virginia Key between Miami and Key Biscayne, Steinberg’s interest in SOSUS continued.

University of Michigan mathematician then supported by ONR for his work in acoustic signal processing. Theodore Birdsall, at Michigan’s Cooley Electronics Laboratory

Contract Proposal PGI-MI-3 Period of Performance 1 July 1972- 30 June 1973

Transmission fluctuations John C. Steinberg, Office of Naval Research. Acoustics Programs, Institute for Acoustical Research

Institute for Acoustical Research, Miami Division of Palisades Geophysical Institute Blauvelt, New York 10913 , 1973

Institute for Acoustical Research, Miami Division of Palisades Geophysical Institute 615 S.W. 2nd Avenue Miami, Florida 33130 






A familiar name here is J. Lamar Worzel Vice President.

Worzel is a cofounder of the Palisades Geophysical Institute




Palisades Geophysical Institute, Inc Proposal PGI-MI-3 My father Dr. C.V. Kimball is listed with Dr. John C. Steinberg under Co-Principal Investigators 


Special Studies Group IAR/ PGI Suite 4 9719 South Dixie Highway Miami, Florida 33156 Special Studies Group IAR/PGI ( Institute for Acoustical Research. Miami Division of the Palisades Geophysical Institute. ) Suite 4 9719 South Dixie Highway Miami, Florida 33156

TI-MIX (Microcomputer Information Exchange) 

Tl-MIX (Texas Instruments Mini/MicrocomputerInformation Exchange)

TI-MIX (Texas Instruments Mini/Microcomputer Information Exchange) 


T-Building United States Naval Facility - Eleuthera, Bahamas

I am the site administrator for NAVFAC Eleuthera Bahamas Facebook Group, US Naval Facility Eleuthera Bahamas and the NAVFAC Bermuda Facebook Group, US Naval Facility Bermuda Facebook Group

US Naval Facility Eleuthera, Bahamas NAVFAC Eleuthera Patch. I found this among other items given to me in helping to clean out my parents house. My father use to do trips there alot when we lived in Miami, Fla 1971-1979 as he did work for the Office Of Naval Research ONR

United States Naval Facility - Eleuthera, Bahamas

A familiar name here is J. Lamar Worzel Vice President. and also mentioned  Dr. John C Steinberg I had begun doing my own naval historical research by connecting the names. And came up with William Maurice Ewing and his student John Lamar Worzel to John C. Steinberg and T.G. Birdsall


Meeting the Submarine Challenge: A Short History of the Naval Underwater Systems Center. U.S. Gov't. Print. Office, 1997. by John Merrill, Lionel D. Wyld. 


I had enjoyed wanting to help others out and I enjoyed watching Emergency Squad 51 as a kid so my father on a trip had picked up for me while he was doing some work with the Naval Underwater Systems Center New London Connecticut  for the Office of Naval Research some how was able to get for me the NUSC Naval Underwater Systems Center New London Connecticut Fire Department 



As a student of the Cooley Electronics Laboratory Department of Electrical Engineering The University of Michigan Ann Arbor, Michigan.

He was a student of Mr. T. G. Birdsall Professor Birdsall 
Please see Professor Emeritus Ted Birdsall Receives Silver Medal in Signal Processing in Acoustics Ted Birdsall - Silver Medal in Signal Processing in Acoustics

From the above website :
Professor Emeritus Theodore G. Birdsall was recently honored with the Silver Medal in Signal Processing in Acoustics by the Acoustical Society of America, "for contributions to signal detection theory and development of coded sequences in underwater acoustics." He is only the second recipient of this award

Theodore G. Birdsall  was a member of the Office of Naval Research's Underwater Sound Advisory group in 1966

During my father's time with the Cooley Electronics Laboratory Department of Electrical Engineering The University of Michigan Ann Arbor, Michigan. He was a contributor to many of the joint effort has been nicknamed MIMI (Miami-MIchigan )
hence the fact that I was born in 1969 at the The University of Michigan Hospital  Ann Arbor, Michigan. And moving to Miami in 1971. After my father's Army two-year active duty contract was over. 

Durring his time with the Cooley Electronics Laboratory Department of Electrical Engineering The University of Michigan Ann Arbor, Michigan. He was a contributor to many things like seen below.

Technical Report No. 161
03674-5-T
THEORY OF SIGNAL DETECTABILITY:
COMPOSITE DEFERRED DECISION THEORY
by
Richard A. Riberts
Approved by:B. F. Barton
for
COOLEY ELECTRONICS LABORATORY
Department of Electrical Engineering
The University of Michigan
Ann Arbor, Michigan
Contract No. Nonr-1224(36)
Office of Naval Research
Department of the Navy
Washington 25, D. C.
March 1965

the computer programs were written by Mr. Kimball. Mr. Kimball incorporated several special techniques in the computations due to the complicated functions that
arose in the analysis. The programs represent a great amount of very good work. Appendix C is due to Mr. Kimball.

Just by google searching Detection theory, or signal detection theory, and goto Detection theory - Wikipedia, the free encyclopedia you can see all the math involved.

As my interest in Amateur Radio Ham Radio and other  related things came from my father



Steinberg JC, Birdsall TG (1966) Underwater sound propagation in the Straits of Florida. J Acoust Soc Am 39: 301–315 * My father is mentioned in the piece of work under acknowledgments C. Kimball on the computer analysis techniques. 



Below is some of my fathers old work

Accession Number : AD0674423
Title :   INTERSYMBOL INTERFERENCE IN BINARY COMMUNICATION SYSTEMS.
Descriptive Note : Technical rept.,
Corporate Author : MICHIGAN UNIV ANN ARBOR COOLEY ELECTRONICS LAB
Personal Author(s) : Kimball,Christopher V.
Report Date : AUG 1968
Pagination or Media Count : 213
Abstract : When a binary communication system transmits symbols through a bandlimited channel, the received symbols will generally overlap in time, giving rise to intersymbol interference. In the presence of noise, intersymbol interference produces a significant increase in the system probability of error. The problem of intersymbol interference and noise is considered here for known, linear, time invariant channels and with added white Gaussian noise. Although a particular underwater acoustic channel is used as a source of motivation, the results presented are equally applicable to other communication channels. Traditional approaches to the intersymbol interference problem--spectrum and transversal (time) equalization are examined. A basis for the comparison of intersymbol interference problems using the concept of phase equalization, is given. A major assumption which limits the interference to that caused by adjacent symbols is made. This assumption is shown to be equivalent to restricting the transmitter to reasonable signalling rates relative to the bandwidth of the channel power spectrum. All subsequent analysis and evaluation are done under this assumption. Several linear filter receivers prevalent in the literature are reviewed and evaluated. Two easily implemented nonlinear receivers are considered as alternatives to the more complex optimized linear filter receivers. The iterated switched-mode receiver is shown to perform better than any optimized linear receiver when intersymbol interference is moderate. (Author)
Descriptors :   *UNDERWATER COMMUNICATIONS, INTERFERENCE, DIGITAL SYSTEMS, MULTIPATH TRANSMISSION, BANDWIDTH, ERRORS, PROBABILITY, INFORMATION THEORY.
Subject Categories : Cybernetics
      Non-radio Communications
Distribution Statement : APPROVED FOR PUBLIC RELEASE

In my father's phd publication Intersymbol Interference In Binary Communications by C.V. Kimball in which he mentions to things here in this blog posting: Iterated Switched-Mode Receiver in which the below shows his Patent US3611149 also mentioned in his Forward in his Intersymbol Interference In Binary Communications phd publication "This report considers a practical problem in underwater communications - intersymbol interference. And the above contributions should be of considerable importance to a designer of a underwater communications system." In which I am proud to show and share his Acoustic Communication Studies (U) An experimental study of techniques for Submarine to Submarine Communications Systems as seen above. 





I am sharing his work for educational purposes.
3611149 is referenced by 15 patents and cites 3 patents.

There is disclosed an iterated switched mode receiver which operates on a received distorted serial binary sequence to diminish or eliminate 
intersymbol interference. The operation of the receiver is predicated upon making two decisions on each symbol. The preliminary or 'first guess' decisions on adjacent symbols are used to eliminate the effects of these symbols on the final decision for each symbol. Signal delays are employed so that it is possible to work with the successor digit as well as the predecessor digit. The preliminary decisions on the succeeding and preceding digits are made by threshold circuit having thresholds at zero. The final decision is made by a variable threshold circuit which receives as its inputs outputs representative of the digit immediately preceding, the digit immediately succeeding and the digit to be processed.
Title
Application Number
04/830,964
Publication Number
3611149
Application Date
June 6, 1969
Publication Date
Inventor
Assignee
The Bottelle Development Corporation a correction would be Assignee is 
(The Battelle Development Corporation)
IPC

Notice the application date is 1969-06-06 which is about on month before I was born July 4th 1969


Amplitude Learning in the Sequential‐Clipper Crosscorrelator Detection Receiver By C.V. Kimball as seen on 70th Meeting Acoustical Society Of America Wednesday 3 November 1965
A comparison is made between an adaptive sequential‐clipper crosscorrelator and the adaptive nonclipping sequential receiver for the case of a signal known except for amplitude; i.e., amplitude is specified by a probability distribution. Both receivers update distributions on the signal amplitude during the observation process to learn the transmitted signal amplitude and, consequently, improve receiver performance. This study compares the amplitude learning of the two receivers during one step of the sequential procedure. Assuming the same initial information, a fixed small‐amplitude signal is applied to the input of each of the receivers and the distributions after observation are studied. From these distributions, the amplitude learning of the sequential‐clipper crosscorrelator receiver is compared with that of the amplitude‐utilizing receiver to provide a measure of the efficiency of the clipper crosscorrelator receiver in learning the signal amplitude. The measure obtained is analogous to the well‐known detection efficiency of 2/π. [Work supported by the U. S. Office of Naval Research Acoustics Programs (Code 468).]


J. Acoust. Soc. Am. Volume 38, Issue 5, pp. 911-911 (1965); (1 page)

Electrical Engineering Department, The University of Michigan, Ann Arbor, 48105 

Acoutical Research Underwater
Underwater Acoustical Research Group ( an informal version of " Information Processing Group Cooley Electronics Research Laboratory" ) 






Finally after so many years of waiting for a National Security Agency NSA FOIA request to be approve  today April 5th 2014, I get to see my fathers paper in the NSA Technical Journal Article 1966 on 
C.V. Kimball A Text Recognition Procedure for Cryptanalysis.  https://www.nsa.gov/news-features/declassified-documents/tech-journals/assets/files/text-recognition.pdf As student University of Michigan.  Paper looks like to was viewed at the International Symposium in Information Theory at UCLA 31 January-2 February 1966 mentions Dr. B.C. Getchell, P1 My research on google mentions  Dr. B.C. Getchell  Butler University



If you look at last page of C.V. Kimball A Text Recognition Procedure for Cryptanalysis.  
Looking at the page of references. You see C.V. Kimball
A RecognitionProcedure for Natural-Language Text with Application to Cryptography,
Unpublished thesis University of Michigan 1965. And Communication Theory of Secrecy Systems is a paper published in 1949 by Claude Shannon  

references. Communication Theory of Secrecy Systems. (Shannon, C.E.) Bell System Technical Journal, 28: 4. October 1949 Pages 656 and Page 709


As my interest in Amateur Radio Ham Radio and other  related things came from my father

Please click here to see about

and
and


Wiley-IEEE Press: Claude E. Shannon: Collected Papers I would like to get a copy of this but cost to much.

Claude Shannon - Father of the Information Age 




And also Theory of signal detectability : composite deferred decision theory 1965 in which my father contribute to by The computer programs were written by Mr. Kimball incorporated several special techniques in the computations due to the complicated functions that
arose in the analysis. The programs represent a great amount of very good work. Appendix C is due to Mr. Kimball. As you interest is your his first son and also that a lot of this has to due in which we use communications in today’s world. 


Two old books of my father The Mathematical Theory Of Communications by Claude E. Shannon and Warren Weaver and Information Theory and Introduction For Scientists and Engineers Raisbeck 


Some of my father’s old books:
Key Papers in the Development of Coding Theory Elwyn R. Berlekamp IEEE Press

Spread Spectrum Techniques Robert C. Dixon IEEE Press

Data Communication Via Fading Channels Kenneth Brayer  IEEE Press

 Secret and Secure: Privacy, Cryptography, and Secure Communication by Clayton C. Pierce
 Analysis of the permutations in the federal data encryption Standard  Clayton C. Pierce
I am proud of my father’s work for Advanced Research Projects Agency (ARPA) Office Of Naval Research ONR and US Army Signal Corps Officer with the US Army Security Agency Support Group The National Security Agency NSA as I was personal around for this from 1969-1979.  As Amateur Radio Ham Radio was in the family 60's-70's (WN8QGF 1965-1966)WA8UNS (1966-1971) -WB4WZR (1971 until recently changed) And my mother was WN8QGE 1965-1966. As with this my Amateur Radio Ham Radio FCC call sign is WA8UNS





I grew up with Drake Amateur Radio Equipment, R. L. Drake Company manufacturer of electronic communications and also KDK 2 meter FM transceiver mobile in the 1970's My father also used a  Vibroplex Bug.,

As WA8UNS was my father's call sign in which changed in 1971 with a 4 call. The Drake Amateur Radio Equipment was sold before we moved to Paris, France in 1984. From 1979-1984 I would be able to build some small kits from Heathkit like a Code Oscillator HD-1416 Morse Heathkit Brand, Heath Co.; Benton Harbor MI and a few others. 



My Fathers old vibroplex morse code keyer mid 60's-70's WN8QGF-WA8UNS ( 1965-1971 ) -WB4WZR ( 1971 until recently changed )


The little guy in the crib is Thomas Q Kimball

My father was in Signal Officer Basic Course, Ft Gordon June through August 1969 but came back to Ann Arbor, Michigan to see my birth July 4th 1969. Wish I could  see a class picture photo from the Signal Officer Basic Course, Ft Gordon June through August 1969 

I became interested in areas of subjects that where related to my growing up with my father's military past and also Amateur Radio Ham Radio as I was born in  July 1969 at the The University of Michigan Hospital  Ann Arbor, Michigan. So I was around for his Army two-year active duty which included US Army Signal Corps Officer with the US Army Security Agency Support Group out of Ft Meade, Md. We had a TDY at Ft Hood, TX December 1969 through May 1970 for MASSTER US Mobile Army Sensor System Test Evaluation and Review SurveillanceTarget Acquisition and Night Observation STANO As it reads from the website masster - 1969-1976 - OTC History

On October 17, 1969, Project MASSTER moved to Building 91025 at the newly designated West Fort Hood, formerly "Killeen Base."and also Ft Meade for the National Security Agency NSA R Group - Research and Engineering. May 1970-71 as a Cryptanalysis . After that we moved to Miami, Fla for the ONR Office Of Naval Research 71-79. The work for ONR Office of Naval Research took my father to US Naval Facility NAVFAC Eleuthera and NAVFAC Bermuda.


I did not know any of my father's work from 1969-1979.  And really didn't learn anything of it until mid to late 1980's.  But did find his old Vietnam Era OG-107 Uniforms in which I had found in box's and would wear the shirts when hiking.


#WA8UNS @WA8UNS #ThomasQuickKimball #ThomasKimball #ridgefieldct #Ridgefield @ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut Thomas Q Kimball of Ridgefield, Connecticut wanted to share :
An experiment study of coherent, matched filter techniques for  submarine-to-submarine communication was conducted, matched filter techniques offer three advantages over existing systems. First, coherent integration allows useful system operation at signal-to-noise ratios significantly below 0 db. Incoherent systems experience a threshold at a 0 db signal-to-noise ratio, which causes system performance to deteriorate rapidly. Second, filtering of the received information symbol with a filter matched to the received symbol waveform reduces the effects of both noise and multipath. Finally, these techniques are compatible with a wideband, randomized transmission format, which reduces the detectability of the signal by unintended receivers. The research program was conducted in two stages. The first stage evaluated communication system performance over 7- and 42- nmi fixed-site ranges. Over 4,000 hours of experimental data were obtained and analyzed to ensure the statistical significance of the measurements. Results from these data showed that reliable communication could be obtained with signal-to-noise ratios below 0 db. A typical experimental system (M6B) transmitted 0.625 bit/sec in a 100-hz band centered on 420 hz. Over a 42-nmi patch this system yielded a bit error probability of 0.01 at an input signal-to-noise ratio of -9 db. Such performance is within 6 db of that obtainable with the optimum receiver operating though a linear time invariant channel with added white Gaussian noise. To determine the applicability of the fixed-site results to the submarine-to-submarine communication problem the second stage of the program investigated the space-time stability of the acoustic medium with a towed source. An experiment was conducted in the deep ocean off Eleuthera, B.I at ranges from 0 to 400 nmi. This experiment indicated only a 10 percent decorrelation  in the channel from one 30-sec interval to the next. Consequently the coherent, matched filter techniques evaluated over the fixed-site ranges are applicable to practical problems involving moving platforms. Based on the results of the experimental program development of a practical submarine-to-submarine communication system using coherent matched filter techniques is proposed. A particular implementation (M7) incorporating a randomized burst-type transmission for detection resistance is suggested as a basis for future work. 

The next step being his (M7) Interim Invention Statement US Navy N00014-75-C-0593 Based on the results of the experimental program development of a practical submarine-to-submarine communication system using coherent matched filter techniques is proposed. A particular implementation (M7) incorporating a randomized burst-type transmission for detection resistance is suggested as a basis for future work. 

In which is my father’s Interim Invention Statement US Navy N00014-75-C-0593 which is listed also as a ONR contract number in ink and on the cover sheet of the Acoustic Communication Studies (U) An experimental study of techniques for Submarine to Submarine Communications Systems. 
Contract Number N00014-73-C-0593 Technical Report July 1971 June 1974  Report Date September 1975 ARPA Advanced Research Projects Agency Office Of Naval Research Code 222

Here in clear blank and white can see where is reads here : Since 1 July 1974 the research program described within has been continued at the University of Miami under contract N00014-75-C-0593 by the Office Of Naval Research The number N00014-75-C-0593 is also my father Christopher V Kimball Interim Invention Statement US Navy N00014-75-C-0593 
In which can be see here please look at 3 page. Full Text : http://www.dtic.mil/docs/citations/ADC003594


As can see above the Reply to me FOIA case number 16-F-1714 at was received 07 November 2016. Department of Defense Office Of Freedom of Information in the 3 paragraph is tell me that
" The technical report ADC003594 suggested a follow-on phase m(7) be explored as future work. The original contract number was ONR contract N00014-73-C-0434 but was continued under N00014-73-C-0593 with the University of Miami. "

You can see that the contract number wrong/incorrect and also there is proof it did continue as a Office Of Naval Research ONR contract number N00014-75-C-0593 which lead to my father's Office Of Naval Research ONR Contract N00014-75-C-0593 which is the same as the Interim Invention Statement US Navy N00014-75-C-0593. So in my impression by denying it exists and or was ever done is wrong.


The above is a In addition, I've found a formal transmission  letter of the document to the Office of Naval Research ONR Resident Representative, dated December 30 1975 

Mr. Edward P Shute Office of Naval Research ONR Resident Representative University of Florida Room 427, Eng & Ind. Bldg. Gainesville, Fla 32611 this letter was sent and included in my letter to the Department of Defense Office Of Freedom of Information. The above letter reads. 

University of Miami
Coral Gables Florida 33124
December 30, 1975

Mr. Edward P Shute 
ONR Resident Representative 
University of Florida Room 427, Eng & Ind. Bldg. 
Gainesville, Fla 32611

Dear Mr. Shute:

REFERENCE: Interim Invention Statement, US Navy N00014-75-C-0593 UM/A/C B8180, PI: Dr. C. Kimball

As requested in Mrs. Kalmus' phone call December 17th regarding subject contract, enclosed find 2 copies of Interim Invention Statement for the same, which has been completed for the University by the Principal Investigator and executed for the University by Mr. Howard R Cottrell, Treasurer. 




 So in a letter from ONR Office Of Naval Research  FOIA dated August 30th 2016 According to our records the contract files destroyed on November 14, 1984 pursuant to the Department of the Navy Management Program Manual (SECNAV 5212.5B)
I tried to google search the above: November 14, 1984 pursuant to the Department of the Navy Management Program Manual (SECNAV 5212.5B) and couldn't find anything also other in the ONR FOIA dated August 30th 2016 in what the ONR  Office Of Naval Research does with US Navy Interim Invention Statement such as my father's Interim Invention Statement US Navy N00014-75-C-0593.

As my father emails writes me:


Ms. Gay is/was at Office of Naval Research ONR 

Dear Ms. Gay,

I'm sorry you were able to locate the requested document.

In the meantime, I've been able to locate the full contract number for
the document; a number including a 'C': N00014-75-C-0593 .  In addition, I've found a formal transmission letter of the document to the ONR Resident Representative, dated December 30 1975 (attached).

(Mr. Edward P Shute  Office of Naval Research ONR Resident Representative University of Florida Room 427, Eng & Ind. Bldg. Gainesville, Fla 32611)

Please advise whether, with this new information, I should:

1. Contact the FOIA appeals office, or

2. Submit a new FOIA request to the Navy or ONR, or

3. Request a continuation from your office.

Two factors suggest that the document should exist somewhere.

1. It's a patent disclosure that might have had long term financial value to the Navy.

2. It's a classified document (Confidential) that couldn't be just thrown in a wastebasket.

At any rate, thanks for your assistance,


Yours,

My father is in his 70’s now and it would be great if he is able to see his work again that he did for The Department of The Navy Office Of Naval Research in which was funded by ARPA (Advanced Research Projects Agency) Defense Advanced Research Projects Agency (DARPA)

Defense Technical Information Center
Accession Number : ADC003594
Title :   Acoustic Communication Studies
Descriptive Note : Technical rept. Jul 1971-Jun 1974
Corporate Author : ROSENSTIEL SCHOOL OF MARINE AND ATMOSPHERIC SCIENCE MIAMI FL


Report Date : Sep 1975
Pagination or Media Count : 47
Abstract : An experimental study of techniques for submarine to submarine communication was conducted. Based on the results of the experimental program, a practical submarine to submarine communication system is proposed. A particular implementation (M7) is suggested as a basis for future work.

Descriptors :   *ACOUSTIC COMMUNICATIONS, *UNDERWATER COMMUNICATIONS, SECURE COMMUNICATIONS, SIGNAL PROCESSING, SIGNAL TO NOISE RATIO, SUBMARINES, TOWED BODIES, UNDERWATER TO UNDERWATER


As I have written below I'm not sure how I feel about ONR Office of Naval Research video's below:




I had thought I had liked the above film about The 70 Years of Innovation: ONR (Office of Naval Research) Reaches a Milestone as Rear Adm. Mat Winter, Chief Of Naval Research and Dr. Lawrence Schuette director of the Office of Naval Research discusses in this youtube video But have changed my feelings about it after this. My own father had spent many years doing contract work for ONR. 65-79 minus his two years Active duty Army. But to me and my father's disappointment as we just leaned from today August 30th 2016 The Office of Naval Research FOIA office that ONR The Department of The Navy had destroyed my father's Interim Invention Statement US Navy N00014-75-C-0593. So why would ONR (Office of Naval Research) The Department of The Navy destroy an Invention as many years of work went into this ?  So in a letter from ONR FOIA dated August 30th 2016 According to our records the contract files destroyed on November 14, 1984 pursuant to the Department of the Navy Management Program Manual (SECNAV 5212.5B)

I personally in my opinion would not have enjoyed hearing this if I was one of those best and brightest scientist ever as mentioned in the ONR (Office of Naval Research) video The 70 Years of Innovation: ONR (Office of Naval Research) Reaches a Milestone after many years of time effort and hours put into contract work and or inventions just to have them sent you a letter reading According to our records the contract files destroyed on November 14, 1984 pursuant to the Department of the Navy Management Program Manual (SECNAV 5212.5B)

 So how could my first ONR FOIA request for N00014-73-C-0593 be found ? 
Is it because it was a Office of Naval Research Contract but it was funded by ARPA (Advanced Research Projects Agency) Defense Advanced Research Projects Agency (DARPA)
  This was to be the next step in his of his Acoustic Communication Studies (U) An experimental study of techniques for Submarine to Submarine Communications Systems. Contract Number N00014-73-C-0593 as seen here: http://www.dtic.mil/docs/citations/ADC003594

The next step being his (M7) Interim Invention Statement US Navy N00014-75-C-0593 Based on the results of the experimental program development of a practical submarine-to-submarine communication system using coherent matched filter techniques is proposed. A particular implementation (M7) incorporating a randomized burst-type transmission for detection resistance is suggested as a basis for future work. 
#WA8UNS @WA8UNS #ridgefieldct #Ridgefield @ridgefield  in #FairfieldCounty #CT  Thomas Q Kimball of Ridgefield, Connecticut wanted to share Some 42 years later I can now see and read some of my own father’s work. This took about 3 years from my first FOIA request 13-F-1279 On 20 August 2013 after spotting my father's work Kimball C.V. Acoustic Communication Studies on a online Journal of Defense Research Cumulative Index, 1969-1978. 


Then to ONR FOIA 16-061 received scanned pdf on July 20th 2016

Though I was a young boy at the time while we had lived in Miami, Florida from 1971-1979. Here is a piece of his work called 
Acoustic Communication Studies (U) An experimental study of techniques for Submarine to Submarine Communications Systems. 
Contract Number N00014-73-C-0593 Technical Report July 1971 June 1974  Report Date September 1975 ARPA Advanced Research Projects Agency Office Of Naval Research Code 222. Supplementary Notes: To be published in the Journal Of Defense Research Series B Tactical Warfare, September 1975 Performing Organization Ocean Engineering Division RSMAS Rosenstiel School of Marine and Atmospheric Science University Of Miami UM-RSMAS 75034 Palisades Geophysical Institute Miami Florida

By this above Table 1. Summary of fixed-site communications experiments. You can tell by Experiment M1 and appears year is 1968 my father had started working on this when still at Cooley Electronics Laboratory University of Michigan. The above in table finished with the Experiment M6C year 1973


The little guy in the crib is Thomas Q Kimball WA8UNS

My father was in Signal Officer Basic Course, Ft Gordon June through August 1969 but came back to Ann Arbor, Michigan to see my birth July 4th 1969. At the The University of Michigan Hospital  Ann Arbor, Michigan. From 1969 until 1971 my father had to do his Army two-year active duty US Army Signal Corps Officer with the US Army Security Agency Support Group out of Ft Meade, Md. We had a TDY at Ft Hood, TX  December 1969 through May 1970 for MASSTER US Army Project Mobile Army Sensor System Test Evaluation and Review Surveillance, Target Acquisition and Night Observation STANO. National Security Agency NSA R Group - Research and Engineering 1970-1971 after that in 1971 we would move to Miami, Florida. 



Thomas with his father somewhere in the Florida Everglades  Circa 1970’s after 1971.

My father who was WB4WZR in Miami then 1971-1979 And WA8UNS from 1966-1971
 Where it all started 69-71 Call sign WA8UNS at our home in Bowie, Md United States  Notice the HF Antenna in the back ground. 


Thomas Q Kimball WA8UNS from Ridgefield, Connecticut and my father Operating Special Station February 4th - 6th 2013

Father and son Operating Amateur Radio Ham Radio at AMC Appalachian Mountain Club Northwest Camp. northwest slope of Bear Mountain in Salisbury, CT.  My Mom did the role of professional Photographer. Thanks :)

I have taken time to re-write some of my father’s work below are samples and or parts of his work. Please note some of the mathematics might be off in my re-write as some of it hard to see. The complete work can be found here: http://www.dtic.mil/docs/citations/ADC003594 so it would be picked up by search engines such as google. I am sharing his work for educational purposes.




An experiment study of coherent, matched filter techniques for  submarine-to-submarine communication was conducted, matched filter techniques offer three advantages over existing systems. First, coherent integration allows useful system operation at signal-to-noise ratios significantly below 0 db. Incoherent systems experience a threshold at a 0 db signal-to-noise ratio, which causes system performance to deteriorate rapidly. Second, filtering of the received information symbol with a filter matched to the received symbol waveform reduces the effects of both noise and multipath. Finally, these techniques are compatible with a wideband, randomized transmission format, which reduces the detectability of the signal by unintended receivers. The research program was conducted in two stages. The first stage evaluated communication system performance over 7- and 42- nmi fixed-site ranges. Over 4,000 hours of experimental data were obtained and analyzed to ensure the statistical significance of the measurements. Results from these data showed that reliable communication could be obtained with signal-to-noise ratios below 0 db. A typical experimental system (M6B) transmitted 0.625 bit/sec in a 100-hz band centered on 420 hz. Over a 42-nmi patch this system yielded a bit error probability of 0.01 at an input signal-to-noise ratio of -9 db. Such performance is within 6 db of that obtainable with the optimum receiver operating though a linear time invariant channel with added white Gaussian noise. To determine the applicability of the fixed-site results to the submarine-to-submarine communication problem the second stage of the program investigated the space-time stability of the acoustic medium with a towed source. An experiment was conducted in the deep ocean off Eleuthera, B.I at ranges from 0 to 400 nmi. This experiment indicated only a 10 percent decorrelation  in the channel from one 30-sec interval to the next. Consequently the coherent, matched filter techniques evaluated over the fixed-site ranges are applicable to practical problems involving moving platforms. Based on the results of the experimental program development of a practical submarine-to-submarine communication system using coherent matched filter techniques is proposed. A particular implementation (M7) incorporating a randomized burst-type transmission for detection resistance is suggested as a basis for future work. 

1 Introduction:
Underwater acoustic communications systems based on coherent matched filter techniques have been studied coherent matched filter techniques have been studied experimentally. Although the specific goal of the research was tactical submarine to submarine communications systems, the results are applicable to other situations. This paper describes extensive fixed-site communication experiments and an important transmission measurements that encourage the immediate consideration of these techniques for submarine communication systems. 

Coherent, matched-filter techniques offer three distinct advantages for submarine communication systems. First coherent integration allows satisfactory operation at low signal-to-noise ratios without the threshold effect that is common to incoherent systems. Second, matched-filter operation reduces the effects of both noise and multipath under varying propagation conditions. And finally these techniques are compatible with a randomized transmission format that reduces the detectability of the communication signal. 

The processing techniques employed in the research are based on well established theory. The acoustic medium is measured to approximate a linear, time-invariant channel with added white Gaussian noise. For such a channel, the optimum receiver is composed of a filter matched to the received signal, following by the threshold device.The matched filter can also be shown to reduce intersymbol interference caused by multipath.

Because the physical channel is distinctly time-varying the received symbol waveform must be continually measured to maintain the required match between the filter and the symbol waveform. This measurement is made possibly including a known probe component in the transmission in addition to the unknown information component. Thurs the communication systems described here perform dual roles channel measurement and information transmission. 

The second stage of the experimental program was to determine the applicability if the fixed-site results to the submarine communication problem. For such an application to be possible, the acoustic medium must be stable in space as well as time. That is the probe measurement  of the channel must remain valid under spatial displacement of the submarine platform consequently a careful measurement of the spatial stability was made as described in Section V. 

The union of the results from the fixed-site communication experiments and the spatial-stability measurements solely indicates the feasibility of coherent matched-filter techniques for the submarine communication systems.This conclusions and others are presented in section VI. An application of these techniques in conjunction with a randomized transmission format is also given. 

II. Transmission  Format
Because of the dual nature of the transmission and the implementation of the receiver processing the signals transmitted by the communication systems have a complicated format. One part of the signal the probe component allows measurements of the channel the other the information component contains the information. Subsequent parts of this section describe these components in detail and explain there choose of transmission format. Section III on the receiver processing completes the explanation. The probe and information components are transmitted interleaved  in time (time multiplexed) as described in section IIb

A.  Basic Signal Element The Digit:
Both components of the transmission are composed of a succession of biphase modulated elements called digits The simplest example of a digit waveform is a rectangular carrier pulse.The probe and information components consist of modulated digits in a prescribed (or in the case of the information component almost prescribed) earlier. In the subsequent discussion no conflict will arise if the digit waveform is assumed to be a rectangular carrier pulse although in practice some amount of band spreading of the digit is desirable as suggested below. For a rectangular carrier pulse the pulse duration and bandwidth are inversely related: that is, once the duration is specified, the bandwidth is also fixed.


B. Probe Component
The probe component of the transmission allows the receiver to measure the channel digit response. Because the information symbols are composed of the combinations of the digits, a filter matched to the symbols can be formed from the digit response. The probe component must be constant and known to the receiver if this measurement is to be successful. 


C. Information Component
The information component can be formed in one of three ways: (1) biphase modulation of single transmitted digits: (2) biphase modulation of groups of digits, where the intragroup structure is constant: or (3) variable symbol modulation in which biphase modulation of groups of digits, where the intragroup structure varies from on symbol to the next is carried out. 

In the subsequent discussion, the difference between a digit-described previously-and a symbol is important. A symbol is a digit or groups of digits used to carry a single bit of information. The objective of the receiver is to determine symbol values, not digit values, thus the difference between the two methods of forming the information components lies in the structure of the symbol waveform. 

1. Single Digit Symbols 
The simplest construction of the information component assigns a single digit to each symbol. A digit transmitted at 0 phase represents a binary one; a digit transmitted at 180-deg phase represents a binary-minus one. This technique was used in the M1,M2, M3 and M4 systems. 

2. Multiple Digit Symbols
If each information symbol is composed of only one digit as described above then potential tradeoff opportunities for the system design are eliminated.


3. Variable Symbol Modulation
If more than one digit is contained in each symbol as described above, the opportunity to alter the symbol composition from one time interval to the next arises.

D. Multiplexing of Probe And Information Components
The transmission in each of the matched-filter communication systems consists of a multiplex of the probe and information components. In choosing the multiplexing technique the particular purpose of the probe component must be considered. For example frequency multiplexing would be inappropriate in the acoustic medium because the digit response measured in one frequency band would not be valid in another frequency band. 

III. Receiver Processing
The receiver in the M5 and M6 communication systems performs a dual role. The first part of this dual role is to measure the existing channel digit response from the probe component of the transmission. 




A. Preliminary Processing
Signals from the receiver hydrophone are transmitted though linear, fixed-gained amplifiers to the processor, the gains of these amplifiers being selected so that no clipping occurs during normal operations. 

B. Probe Processing
The primary objective of the probe processing is to determine the channel digit response. A secondary but important , objective of the probe processing is to measure the basic transmission characteristics of the medium to aid in evaluation and understanding of the system performance. 

1. Channel Digit Response Measurements
As mentioned above, the primary objective of the probe processing is to derive the approximate channel digit response p(t) Let p (k,i) be the sampled data representation of p(t) obtained in the kth measurement interval. 


2. Measurement of Signal and Noise Powers
The wideband signal and noise powers, SP and NP are measured to allow evaluation of the system performance.

C. Information Component Processing 
The objective of the information component processing is to make correct decisions on the transmitted symbol values. These decisions can be scored against known answers in the case of a periodic transmission. For demonstration purposes the received values can be printed as characters on a teletype. 

1. Matched-Filter Operation
The first step in the processing of the kth information component is to form a coherent average a,(k,i) of the information component:

2. Decision Process
To determine the symbol values a zero threshold is applied to the symbol matched-filter outputs L(k,i).

3. Scoring of Receiver Decisions
To evaluate the system error performance the receiver decisions d(i) are scored against know correct values. This can be done as long as the symbol values in the information component are known as they are in the case of periodic transmission.

D. Synchronization
In the preceding discussion synchronization  between the receiver and received signal has been assumed. When a periodic transmission is sent the probe and information components are identical and no synchronization is necessary. 

E. Implementation 
The receiver processing for both communications systems was performed by small general purpose digital computers frequently called minicomputers. The M5 systems were implemented on a Digital Equipment Corporation LINC-8 computer with a 4,096-word (12 bits/word) memory. The M6 systems were implemented on a DEC PDP-8E system with an 8,192 word (12 bits/word) memory. 


CEL   Technical Memorandum No. 104
03604-1-M
OPERATOR'S MANUAL
for the
M4 COMMUNICATIONS EXPERIMENT
by
David Jaarsma
COOLEY ELECTRONICS LABORATORY
Department of Electrical Engineering
The University of Michigan
Ann Arbor, Michigan
Contract No. N00014-67-A-0181-0032
Office of Naval Research (Code 468)
Department of the Navy
Washington, D. C. 20360
August 1970

I. INTRODUCTION
The M4 Communication System is a complete revision of the
M3 Communication System as constructed by C.V. Kimball in
June 1969.

Some photos diagrams from the above work as to computer and system set up which is interesting to me as you can see a Receiving and a Hydrophone Line


Photos of computers below:
Receiving Hydrophone Line 100 Hz Bandpass Filter etc.

PDP-8 - Wikipedia, the free encyclopedia

   DIGITAL EQUIPMENT CORPORATION PDP 8/E 
FIELD-8 computer Field-8/E System 1 with what looks like a General Radio 1161-A Coherent Decade Frequency Synthesizer ontop of the FIELD-8 computer Field-8/E System 1







LINC-8 - Wikipedia, the free encyclopedia


( Pictured ) The LINC-8 contained one PDP-8 CPU and one LINC  The LINC (Laboratory INstrument Computer)  CPU, partially emulated by the PDP-8 LINC-8 was the name of a minicomputer manufactured by Digital Equipment Corporation between 1966 and 1969. ( Pictured ) The Teletype Corporation ASR 33 Teletype 


The Digital Equipment Corporation DEC PDP-8e PDP-8m Small Computer Handbook with Digital Equipment Corporation, PDP-11 Processor Handbook
IV. Experimental Program
Five long-term experiments (M5A, M5B, M6A, M6B, and M6C) were performed between fixed sites in the Straits of Florida to evaluate the effectiveness of coherent integration/matched-filter techniques.

A. Differences Among Experiments
In each of the five experiments the transmission was generated by the source off Fowey Rocks Light. During the M5 experiment signals were received at a hydrophone located 7 nmi from the Fowey Rocks source while in the M6 experiment signals were received at the Bimini hydrophone 42 nmi from the source.

B. Experimental Results
The five experiments yielded data on both acoustic transmission conditions and system error performance. In this section only measurements that bear on the evaluation of system error performance or on future applications on the communication system are discussed. 


1. Signal-to-Noise Ratio Histograms
To interpret the communication performance data, an understanding of the signal and noise environment of each experiment is necessary.


2. Communication System Performance
Evaluation of communication system performance is a difficult problem when one is confronted with a varying conditions of the acoustic medium. 


3. Channel Stability Measurements
The utility of the match-filter technique studied here is highly dependent on the stability of the medium. If the acoustic channel changes significantly from the time of the probe measurement to the time of the information component processing then the filter will not be properly matched and an increase in errors can be expected. 

V. Spatial Stability Measurements
The preceding sections described the operation and performance of an underwater acoustic communication system operating between two fixed points. In a practical submarine communication system one or both ends of the acoustic channel is in motion so a spatial variations  as well as temporal variations are important. This sections describes two measurements of the spatial stability of the medium and provides the foundation for the extension of the fixed-site communication techniques previously discussed to the submarine communication problem. 


The fixed-site experiments have shown the temporal stability of the medium to be sufficient to allow integration times of the order of one minute. From a purely geometric point of view the medium should also be stable under spatial displacements that are common to submarine platforms. For example a submarine on a 10-knot zero Doppler track at a range of 100 nmi subtends less than 0.1 deg of arc in one minute. The wideband characteristics of the acoustic channel would not be expected to change significantly under such a displacement. Nevertheless careful measurements have been made to validate this intuitive understanding.


A. Coherent Cross Correlation without Coherent Integration
In this measurement technique the spatial stability of the medium was measured in terms of normalized correlation coefficients p1(i) analogous to the correlation coefficient p(k) studied in the M5 and M6 experiments. Because of the presence of the Doppler effect however the definition had to be modified slightly. The transmission was a 15-digit pseudorandom sequence similar to that of the M5A,M5B and M6A experiments. 




The preliminary spatial stability measurements were conducted with a towed HX90 source in the Straits of Florida during September 1973. Figure 14 depicts the vessel track during these experiments. The source was towed at approximately 200-ft depth with vessel speeds of 2.5, 5, and 10 knots. Signals from the source were received at a hydrophone approximately 7 mmi from the Fowey Rocks Light and were sent via cables to the laboratory on shore. 

B. Coherent Cross Correlation with Coherent Integration
After the preliminary spatial stability measurements in September 1973 development of a measurement technique including coherent ingrain was initiated. The requirement for coherent integration was based on two considerations. First the September 1973 experiments showed that noise and surface modulation precluded measurement of the spatial stability when no coherent integration was used and second an opportunity to study spatial stability at long ranges in the deep ocean was available. The input signal-to-noise ratio at these ranges required coherent integration to obtain adequate representation of the signal. The resulting measurement technique which employs coherent cross correlation with coherent integration is described below. Because of the need to perform coherent integration as well as to accommodate Doppler effects fast Fourier transform techniques (FFT) were employed.
1. Operation at Zero Doppler
To understand the operation of the operation of the measurement technique first consider its operation with zero Doppler. Because the transform interval contains nearly 22 sequence periods every 22nd transform spectral line from the carrier will contain signal energy. The intervening 21 transform lines will contain only noise energy. Consequently a processing gain of 22 (13.4 db) can be achieved by considering only every 22nd transform spectral line about the carrier. 

2. Operation with Nonzero Doppler
Measurement of the correlation coefficient p2(k) and the input and output signal-to-noise ratios is not significantly more difficult when the Doppler is nonzero. Let f be the Doppler-shifter carrier frequency

If the difference between f and the receiver center frequency f is small then the effect of Doppler on the received signal is approximately a frequency translation. Such a frequency translation acts as a fixed offset between the zero-Doppler location of the signal spectral lines and the actual received spectral lines.


3. Experimental Results
During January 1974 the HX90 acoustic source was towed in the deep ocean between Eleuthera and Bermuda. The approximate vessel track relative to the hydrophone is shown in Fig 18. Signals from the source were received at a fixed hydrophone and processed with the the coherent integration technique described above. The ranges of the experiment varied from 0 to 400 mmi with most of the experiment being conducted at ranges between 300 and 400 mmi. During the experiment the vessel speed was maintained at approximately 6 knots.

VI. Future Applications and Conclusions
The effectiveness of coherent matched-filter techniques was demonstrated in fixed-site experiments in the Straits of Florida. The application of coherent integration over time intervals of the order of one minute yield satisfactory operation at input signal-to-noise ratios below 0 db. By matched filtering of the received signal the effects of selective fading and intersymbol interference due to multipath were reduced. Massive amounts of data (over 4,000 hours) on system performance add significance to the results obtained. 

To apply coherent matched-filter techniques to the submarine communication problem an understanding of the medium’s spatial as well as temporal stability is required. A ten-day experiment in the Atlantic between Eleuthera and Bermuda with a towed source and a fixed hydrophone was conducted to measure spatial stability.The results from this experiment indicated the presence of sufficient spatial stability over intervals of at least 30 sec at six knots at ranges from 0 to 400 nmi.

The combination of fixed-site communication system results and the spatial stability measurements establishes the feasibility of coherent matched-filter techniques for submarine communications. Advantages to be gained from these techniques include reliable operation at low signal-to-noise ratios and under varying propagation conditions. Further randomized transmission formats can be employed to reduce the detectability of the communication signal. Because the technology required to implement coherent matched-filter techniques is readily available their application to submarine communications should be initiated. 


1. Subsidiary Conclusions
The experimental program yield several secondary results that should be considered in subsequent submarine communication system design.

First the acoustic medium exhibits significant variance in input signal-to-noise ratio SNR even under fixed-site conditions. Standard deviations of SNR of the order of 5 db can generally be expected. These variations require that any reliable communication system be able to operate successfully over a wide range of input signal-to-noise ratios. Coherent matched-filter systems satisfy this requirement more closely than the incoherent systems currently in use. 

Second impulsive noise must be accounted for in any system in which low PE 0.001 bit error probabilities are required. The presence of infrequent high-energy noise pulses can limit the error probability to a fixed level independent of the average input signal-to-noise ratio. Soft limiting of the receiver input in conjunction with error-correcting codes can be used to overcome this limitation. 


B. Suggested Application
The M5 and M6 communication systems were designed specifically for the evaluation of coherent matched-filter techniques. Consequently, their structures lack many features required of a practical submarine communication system. For example, the transmission in the M5 and M6 systems is continuous and synchronization is performed by the operator. Neither of these characteristics is acceptable in practice. The purpose of this section is to suggest one realization of a coherent, matched-filter  communications system that is suitable for operational use. Only the structure of the transmission and the expected performance characteristics are given here. The details of the receiver processing and implementation will be available in the future. 


The M7 system described below has been designed to provide an application of coherent matched-filter techniques that satisfy the requirements previously stated. Specifically the M7 system utilizes a burst type of transmission with a randomized format. The structure of the transmission is based entirely on an arbitrary random binary sequence that can be changed on a daily basis if desired. The only constraint on the sequence is that it must be know to both the transmitter and receiver and have the same statistical properties as other random sequences. 

In the M7 system the probe and information components are phase multiplexed instead of time multiplexed as in the M5 and M6 systems. Let a(t) be a low-pass digit of duration T and let f be the carrier frequency, then the M7 transmission is given by ____. 

The first term in the sum is the probe component and the second is the information component. The coefficients __ are derived from a random binary sequence q(i) and the information component as indicated below. 

Let __be a random binary sequence of length 2k The coefficients for the probe component qr(i) are simply the q(i)s of even index.


Assume that K information bits e(i) are to be transmitted. Further assume that Kb is a factor of Ki so that K=Kb Ks for some integer K Then the coefficients for the information component are given by

Since both coefficients q (i) and q (i)  are derived from a random sequence q(i) the transmission m(t) can be expected to be free from periodicities or strong spectral components. If the input signal-to-noise ratio of an intercept receiver is below 0 db the detectability of the M7 transmission will be very low. If the input signal-to-ratio of the intercept receiver is above 0 db conventional power measurements techniques are applicable. Consequently the M7 technique (and any other) can be considered detection resistant only if the intercept receiver in denied an adequate  signal-to-noise ratio that is beyond a certain range. 

To provide an illustration of the performance to be expected of the M7 system a specific practical example is given: Assume that the system bandwidth is 100 hz and that the transmission duration is limited to 40 sec. Let n(t) be 10-m sec rectangular pulse, so that the spectrum of the n(t) fills the system bandwidth. Then K, equals 4,000. Table 5 gives the system performance for several choices of K. The column marked “minimum operating SNR” gives the input signal-to-noise ratio expected to yield a bit probability of error of 0.001. This signal-to-noise ratio is obtained by taking the theoretical signal-to-noise ratio required to obtain such performance and then adding a +6 db differential to account for non-idealities. Note the low signal-to-noise ratios for which the 0.001 error probability is expected. 
-----------------------


Under Acknowledgements he mentions Navy CDR Don Koehler and company of the US Naval Facility Eleuthera during the January 1974 experiments.

Special appreciation is due to Dr. Chester A. Jacewitz, Mr. John J Shearer and Ms. Mary Forlenza for their contributions to the research program

And References 
1) C.V. Kimball Intersymbol interference in binary communication systems technical report 195 Cooley Electronics Laboratory University of Michigan August 1968
2) C.V. Kimball A MIMI Communication Experiment technical report 197 Cooley Electronics Laboratory University of Michigan 
3) David Jaarsma Experimental Research in Binary Communications using the Miami 42 mile Underwater Acoustic Channel technical report 207
4) John C. Steinberg and Ted G. Birdsall Underwater Sound Propagation in the Straits of Florida 1966.
* My father is mentioned in the piece of work under acknowledgments C.V. Kimball on the computer analysis techniques. 




Some of the Distribution List to my father’s  Acoustic Communication Studies (U) An experimental study of techniques for Submarine to Submarine Communications Systems. Contract Number N00014-73-C-0593. I would like to think that maybe his Interim Invention Statement US Navy N00014-75-C-0593 might have had the same Distribution List is in hopes that one of these other agencies within the The Department of The Navy might still have a copy. 

Advanced Research Projects Agency
1400 Wilson Blvd.
Arlington, Virginia 33309
Attn: Dr. John Richard Seesholtz
Dr. R Cook

Office of Naval Research (Code 222)
800 N. Quincy St.
Arlington, Virginia 22217
Att: Dr. Alan O. Sykes

Director
Naval Research Laboratory
Washington, D.C 20390
Att: Dr. William Hahn
Mr. Caldwell McCoy
Technical Information Division

Commander
Naval Ordnance Laboratory
Acoustics Division
White Oak, Silver Spring, Maryland 20907
Attn: Dr. Zaka Slawsky

Commander
Naval Undersea Center
San Diego, California 92132
Attn: Mr. Darrell Marsh
Dr. Harper Whitehouse

Commanding Officer & Director
Naval Underwater Systems Center
Fort Trumbull
New London, Connecticut 06321
Attn: Dr. Alan V. Ellinthorpe
Dr. Albert H Nuttall
Dr. Dan Viccione

Commander
Naval Air Development Center
Johnsville, Warminster, Pennsylvania 18974

Commanding Officer
Naval Ship Research & Development Center
Washington, D.C 20034

NISC Naval Intelligence Support Center
4301 Suitland Road
Washington, D.C. 20390
Attn : Johann Martinek
Mr. E. Bisset

Commander
Naval Ordnance Systems Command
Code ORD-03C
Navy Department
Washington, D.C. 20360

Commander
Naval Sea Systems Command
Washington, D.C 20360
Attn: Mr. Carey D. Smith
Mrs. Dolly Hoffman 

Commander
Naval Undersea Research & Development Center
3202 E Foothill Blvd.
Pasadena, California 91107

Naval Electronics Systems Command
Washington, D.C. 20360
Attn: Mr. M. Parker
Mr. I. Smitten

Naval Electronics Systems Command
Submarine Integration Divison 
PME 117-23
Washington, D.C. 20360
Attn: Mr. Weinberger

Chief of Naval Operations
801 N. Randolph Street
Arlington, Virginia 22203
Attn: Code OP-095C

Defense Documentation Center
Cameron Station
Alexandria, Virginia 22314

Dr. Harry Sonnemann
Office of the Assistant Secretary of the Navy
(Research & Development)
Room 4D745, Pentagon
Washington, DC 20350



UPDATE :
To me and my father's disappointment as we just learned from August 30th 2016 The Office of Naval Research FOIA office that ONR The Department of The Navy had destroyed my father's Interim Invention Statement US Navy N00014-75-C-0593. 

The next step being his (M7) Interim Invention Statement US Navy N00014-75-C-0593 Based on the results of the experimental program development of a practical submarine-to-submarine communication system using coherent matched filter techniques is proposed. A particular implementation (M7) incorporating a randomized burst-type transmission for detection resistance is suggested as a basis for future work. 

So why would ONR The Department of The Navy destroy an Invention as many years of work went into this ?  So in a letter from ONR FOIA dated August 30th 2016 According to our records the contract files destroyed on November 14, 1984 pursuant to the Department of the Navy Management Program Manual (SECNAV 5212.5B)

My father is in his 70’s now and it would be great if he is able to see his work again that he did for The Department of The Navy Office Of Naval Research in which was funded by ARPA (Advanced Research Projects Agency) Defense Advanced Research Projects Agency (DARPA)

Defense Technical Information Center
Accession Number : ADC003594
Title :   Acoustic Communication Studies
Descriptive Note : Technical rept. Jul 1971-Jun 1974
Corporate Author : ROSENSTIEL SCHOOL OF MARINE AND ATMOSPHERIC SCIENCE MIAMI FL


Report Date : Sep 1975
Pagination or Media Count : 47
Abstract : An experimental study of techniques for submarine to submarine communication was conducted. Based on the results of the experimental program, a practical submarine to submarine communication system is proposed. A particular implementation (M7) is suggested as a basis for future work.

Descriptors :   *ACOUSTIC COMMUNICATIONS, *UNDERWATER COMMUNICATIONS, SECURE COMMUNICATIONS, SIGNAL PROCESSING, SIGNAL TO NOISE RATIO, SUBMARINES, TOWED BODIES, UNDERWATER TO UNDERWATER

Subject Categories : Acoustic Detection and Detectors
      Acoustics
      Non-radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE


Thomas Q Kimball then at home in 1971-1979 at 8441 SW 142nd Street Miami, Florida 33158 

Thomas Q Kimball with the SWSC Sheeler Winton Swim Club 1970's

WA8UNS Thomas Q Kimball of Ridgefield, Connecticut  was a member of  The Sheeler Winton Swim Club in Miami, Florida 1971-1979 As it was truly a great place to swim.


Many thanks to Jim Donovan CAPT USN (Ret) Director IUSSCAA and the group for allowing me to become a member of the IUSS CAESAR Alumni Association, Integrated Undersea Surveillance System Caesar Alumni Association.

The Third Battle Innovation in the U.S. Navy's Silent Cold War Struggle with Soviet Submarines By Owen R. Cole Jr. 


Please click here to see:

The US Naval Facility Eleuthera Bahamas is mentioned in The Third Battle Innovation in the U.S. Navy's Silent Cold War Struggle with Soviet Submarines


#WA8UNS @WA8UNS #ridgefieldct #Ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut Thomas Q Kimball of Ridgefield, Connecticut is the monitor for my US Naval Facility Eleuthera Bahamas Facebook Group in which is a closed group. As I only approve people are former employees and their dependents family member I approve the request to join. I request if you would like to join please message me as when you where there and a photo if possible. 


The picture collection of US Naval Facility Eleuthera, Bahamas, NAVFAC Eleuthera 1970's Pictures taken by father while working for the Office Of Naval Research ONR.

Please see and read pages 90-97 of the Papers in Australian Maritime Affairs | Royal Australian Navy Papers in Australian Maritime Affairs No. 21. Australian Maritime Issues 2007 - SPC-A Annual






Nicely written as to my 8 1/2 years living in Miami, Florida between 1971-1979 before moving to Connecticut in 1979.

The below information is 


And
Please see pdf link on Using the Ocean to Hunt Soviet Submarines, 1950-1961 History – The American Sound Surveillance System: Using the Ocean to Hunt Soviet Submarines, 1950-1961 Volume 5 Number 2. The American Sound Surveillance System:  Gary E. Weir,. U.S. Naval Historical Center;
The below mentions two names of folks that my father had worked with from being a student of Theodore Birdsall, at Michigan’s Cooley Electronics Laboratory and with working with John Steinberg

Steinberg worked for seven years on Project Jezebel, the low frequency acoustic research that made the Sound Surveillance System [SOSUS] possible.

When he left Bell Labs for retirement and a research post at the University of Miami’s facility on Virginia Key between Miami and Key Biscayne, Steinberg’s interest in SOSUS continued.

University of Michigan mathematician then supported by ONR for his work in acoustic signal processing. Theodore Birdsall, at Michigan’s Cooley Electronics Laboratory

Contract Proposal PGI-MI-3 Period of Performance 1 July 1972- 30 June 1973

Transmission fluctuations John C. Steinberg, Office of Naval Research. Acoustics Programs, Institute for Acoustical Research

Institute for Acoustical Research, Miami Division of Palisades Geophysical Institute Blauvelt, New York 10913 , 1973

Institute for Acoustical Research, Miami Division of Palisades Geophysical Institute 615 S.W. 2nd Avenue Miami, Florida 33130 






A familiar name here is J. Lamar Worzel Vice President.

Worzel is a cofounder of the Palisades Geophysical Institute




Palisades Geophysical Institute, Inc Proposal PGI-MI-3 My father Dr. C.V. Kimball is listed with Dr. John C. Steinberg under Co-Principal Investigators 


Special Studies Group IAR/ PGI Suite 4 9719 South Dixie Highway Miami, Florida 33156 Special Studies Group IAR/PGI ( Institute for Acoustical Research. Miami Division of the Palisades Geophysical Institute. ) Suite 4 9719 South Dixie Highway Miami, Florida 33156

TI-MIX (Microcomputer Information Exchange) 

Tl-MIX (Texas Instruments Mini/MicrocomputerInformation Exchange)

TI-MIX (Texas Instruments Mini/Microcomputer Information Exchange) 


#WA8UNS @WA8UNS #ThomasQuickKimball #ThomasKimball #ridgefieldct #Ridgefield @ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut Thomas Q Kimball of Ridgefield, Connecticut wanted to share The T-Building United States Naval Facility - Eleuthera, Bahamas

I am the site administrator for NAVFAC Eleuthera Bahamas Facebook Group, US Naval Facility Eleuthera Bahamas and the NAVFAC Bermuda Facebook Group, US Naval Facility Bermuda Facebook Group

US Naval Facility Eleuthera, Bahamas NAVFAC Eleuthera Patch. I found this among other items given to me in helping to clean out my parents house. My father use to do trips there alot when we lived in Miami, Fla 1971-1979 as he did work for the Office Of Naval Research ONR

#WA8UNS @WA8UNS #ThomasQuickKimball #ThomasKimball #ridgefieldct #Ridgefield @ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut Thomas Q Kimball of Ridgefield, Connecticut The United States Naval Facility - Eleuthera, Bahamas

#WA8UNS @WA8UNS #ThomasQuickKimball #ThomasKimball #ridgefieldct #Ridgefield @ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut Thomas Q Kimball of Ridgefield, Connecticut The United States Naval Facility - Eleuthera, Bahamas
 #WA8UNS @WA8UNS #ThomasQuickKimball #ThomasKimball #ridgefieldct #Ridgefield @ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut Thomas Q Kimball of Ridgefield, Connecticut The United States Naval Facility - Eleuthera, Bahamas
 #WA8UNS @WA8UNS #ThomasQuickKimball #ThomasKimball #ridgefieldct #Ridgefield @ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut Thomas Q Kimball of Ridgefield, Connecticut The United States Naval Facility - Eleuthera, Bahamas

A familiar name here is J. Lamar Worzel Vice President. and also mentioned  Dr. John C Steinberg I had begun doing my own naval historical research by connecting the names. And came up with William Maurice Ewing and his student John Lamar Worzel to John C. Steinberg and T.G. Birdsall


Meeting the Submarine Challenge: A Short History of the Naval Underwater Systems Center. U.S. Gov't. Print. Office, 1997. by John Merrill, Lionel D. Wyld. 


I had enjoyed wanting to help others out and I enjoyed watching Emergency Squad 51 as a kid so my father on a trip had picked up for me while he was doing some work with the Naval Underwater Systems Center New London Connecticut  for the Office of Naval Research some how was able to get for me the NUSC Naval Underwater Systems Center New London Connecticut Fire Department 



As a student of the Cooley Electronics Laboratory Department of Electrical Engineering The University of Michigan Ann Arbor, Michigan.

He was a student of Mr. T. G. Birdsall Professor Birdsall 
Please see Professor Emeritus Ted Birdsall Receives Silver Medal in Signal Processing in Acoustics Ted Birdsall - Silver Medal in Signal Processing in Acoustics

From the above website :
Professor Emeritus Theodore G. Birdsall was recently honored with the Silver Medal in Signal Processing in Acoustics by the Acoustical Society of America, "for contributions to signal detection theory and development of coded sequences in underwater acoustics." He is only the second recipient of this award

Theodore G. Birdsall  was a member of the Office of Naval Research's Underwater Sound Advisory group in 1966

During my father's time with the Cooley Electronics Laboratory Department of Electrical Engineering The University of Michigan Ann Arbor, Michigan. He was a contributor to many of the joint effort has been nicknamed MIMI (Miami-MIchigan )
hence the fact that I was born in 1969 at the The University of Michigan Hospital  Ann Arbor, Michigan. And moving to Miami in 1971. After my father's Army two-year active duty contract was over. 

Durring his time with the Cooley Electronics Laboratory Department of Electrical Engineering The University of Michigan Ann Arbor, Michigan. He was a contributor to many things like seen below.

Technical Report No. 161
03674-5-T
THEORY OF SIGNAL DETECTABILITY:
COMPOSITE DEFERRED DECISION THEORY
by
Richard A. Riberts
Approved by:B. F. Barton
for
COOLEY ELECTRONICS LABORATORY
Department of Electrical Engineering
The University of Michigan
Ann Arbor, Michigan
Contract No. Nonr-1224(36)
Office of Naval Research
Department of the Navy
Washington 25, D. C.
March 1965

the computer programs were written by Mr. Kimball. Mr. Kimball incorporated several special techniques in the computations due to the complicated functions that
arose in the analysis. The programs represent a great amount of very good work. Appendix C is due to Mr. Kimball.

Just by google searching Detection theory, or signal detection theory, and goto Detection theory - Wikipedia, the free encyclopedia you can see all the math involved.

As my interest in Amateur Radio Ham Radio and other  related things came from my father



Steinberg JC, Birdsall TG (1966) Underwater sound propagation in the Straits of Florida. J Acoust Soc Am 39: 301–315 * My father is mentioned in the piece of work under acknowledgments C. Kimball on the computer analysis techniques. 



Below is some of my fathers old work

Accession Number : AD0674423
Title :   INTERSYMBOL INTERFERENCE IN BINARY COMMUNICATION SYSTEMS.
Descriptive Note : Technical rept.,
Corporate Author : MICHIGAN UNIV ANN ARBOR COOLEY ELECTRONICS LAB
Personal Author(s) : Kimball,Christopher V.
Report Date : AUG 1968
Pagination or Media Count : 213
Abstract : When a binary communication system transmits symbols through a bandlimited channel, the received symbols will generally overlap in time, giving rise to intersymbol interference. In the presence of noise, intersymbol interference produces a significant increase in the system probability of error. The problem of intersymbol interference and noise is considered here for known, linear, time invariant channels and with added white Gaussian noise. Although a particular underwater acoustic channel is used as a source of motivation, the results presented are equally applicable to other communication channels. Traditional approaches to the intersymbol interference problem--spectrum and transversal (time) equalization are examined. A basis for the comparison of intersymbol interference problems using the concept of phase equalization, is given. A major assumption which limits the interference to that caused by adjacent symbols is made. This assumption is shown to be equivalent to restricting the transmitter to reasonable signalling rates relative to the bandwidth of the channel power spectrum. All subsequent analysis and evaluation are done under this assumption. Several linear filter receivers prevalent in the literature are reviewed and evaluated. Two easily implemented nonlinear receivers are considered as alternatives to the more complex optimized linear filter receivers. The iterated switched-mode receiver is shown to perform better than any optimized linear receiver when intersymbol interference is moderate. (Author)
Descriptors :   *UNDERWATER COMMUNICATIONS, INTERFERENCE, DIGITAL SYSTEMS, MULTIPATH TRANSMISSION, BANDWIDTH, ERRORS, PROBABILITY, INFORMATION THEORY.
Subject Categories : Cybernetics
      Non-radio Communications
Distribution Statement : APPROVED FOR PUBLIC RELEASE

In my father's phd publication Intersymbol Interference In Binary Communications by C.V. Kimball in which he mentions to things here in this blog posting: Iterated Switched-Mode Receiver in which the below shows his Patent US3611149 also mentioned in his Forward in his Intersymbol Interference In Binary Communications phd publication "This report considers a practical problem in underwater communications - intersymbol interference. And the above contributions should be of considerable importance to a designer of a underwater communications system." In which I am proud to show and share his Acoustic Communication Studies (U) An experimental study of techniques for Submarine to Submarine Communications Systems as seen above. 





I am sharing his work for educational purposes.
3611149 is referenced by 15 patents and cites 3 patents.

There is disclosed an iterated switched mode receiver which operates on a received distorted serial binary sequence to diminish or eliminate 
intersymbol interference. The operation of the receiver is predicated upon making two decisions on each symbol. The preliminary or 'first guess' decisions on adjacent symbols are used to eliminate the effects of these symbols on the final decision for each symbol. Signal delays are employed so that it is possible to work with the successor digit as well as the predecessor digit. The preliminary decisions on the succeeding and preceding digits are made by threshold circuit having thresholds at zero. The final decision is made by a variable threshold circuit which receives as its inputs outputs representative of the digit immediately preceding, the digit immediately succeeding and the digit to be processed.
Title
Application Number
04/830,964
Publication Number
3611149
Application Date
June 6, 1969
Publication Date
Inventor
Assignee
The Bottelle Development Corporation a correction would be Assignee is 
(The Battelle Development Corporation)
IPC

Notice the application date is 1969-06-06 which is about on month before I was born July 4th 1969


Amplitude Learning in the Sequential‐Clipper Crosscorrelator Detection Receiver By C.V. Kimball as seen on 70th Meeting Acoustical Society Of America Wednesday 3 November 1965
A comparison is made between an adaptive sequential‐clipper crosscorrelator and the adaptive nonclipping sequential receiver for the case of a signal known except for amplitude; i.e., amplitude is specified by a probability distribution. Both receivers update distributions on the signal amplitude during the observation process to learn the transmitted signal amplitude and, consequently, improve receiver performance. This study compares the amplitude learning of the two receivers during one step of the sequential procedure. Assuming the same initial information, a fixed small‐amplitude signal is applied to the input of each of the receivers and the distributions after observation are studied. From these distributions, the amplitude learning of the sequential‐clipper crosscorrelator receiver is compared with that of the amplitude‐utilizing receiver to provide a measure of the efficiency of the clipper crosscorrelator receiver in learning the signal amplitude. The measure obtained is analogous to the well‐known detection efficiency of 2/π. [Work supported by the U. S. Office of Naval Research Acoustics Programs (Code 468).]


J. Acoust. Soc. Am. Volume 38, Issue 5, pp. 911-911 (1965); (1 page)

Electrical Engineering Department, The University of Michigan, Ann Arbor, 48105 

Acoutical Research Underwater
Underwater Acoustical Research Group ( an informal version of " Information Processing Group Cooley Electronics Research Laboratory" ) 






Finally after so many years of waiting for a National Security Agency NSA FOIA request to be approve  today April 5th 2014, I get to see my fathers paper in the NSA Technical Journal Article 1966 on 
C.V. Kimball A Text Recognition Procedure for Cryptanalysis.  https://www.nsa.gov/news-features/declassified-documents/tech-journals/assets/files/text-recognition.pdf As student University of Michigan.  Paper looks like to was viewed at the International Symposium in Information Theory at UCLA 31 January-2 February 1966 mentions Dr. B.C. Getchell, P1 My research on google mentions  Dr. B.C. Getchell  Butler University



If you look at last page of C.V. Kimball A Text Recognition Procedure for Cryptanalysis.  
Looking at the page of references. You see C.V. Kimball
A RecognitionProcedure for Natural-Language Text with Application to Cryptography,
Unpublished thesis University of Michigan 1965. And Communication Theory of Secrecy Systems is a paper published in 1949 by Claude Shannon  

references. Communication Theory of Secrecy Systems. (Shannon, C.E.) Bell System Technical Journal, 28: 4. October 1949 Pages 656 and Page 709


As my interest in Amateur Radio Ham Radio and other  related things came from my father

Please click here to see about

and
and


Wiley-IEEE Press: Claude E. Shannon: Collected Papers I would like to get a copy of this but cost to much.

Claude Shannon - Father of the Information Age 




And also Theory of signal detectability : composite deferred decision theory 1965 in which my father contribute to by The computer programs were written by Mr. Kimball incorporated several special techniques in the computations due to the complicated functions that
arose in the analysis. The programs represent a great amount of very good work. Appendix C is due to Mr. Kimball. As you interest is your his first son and also that a lot of this has to due in which we use communications in today’s world. 


Two old books of my father The Mathematical Theory Of Communications by Claude E. Shannon and Warren Weaver and Information Theory and Introduction For Scientists and Engineers Raisbeck 


Some of my father’s old books:
Key Papers in the Development of Coding Theory Elwyn R. Berlekamp IEEE Press

Spread Spectrum Techniques Robert C. Dixon IEEE Press

Data Communication Via Fading Channels Kenneth Brayer  IEEE Press

 Secret and Secure: Privacy, Cryptography, and Secure Communication by Clayton C. Pierce
 Analysis of the permutations in the federal data encryption Standard  Clayton C. Pierce
I am proud of my father’s work for Advanced Research Projects Agency (ARPA) Office Of Naval Research ONR and US Army Signal Corps Officer with the US Army Security Agency Support Group The National Security Agency NSA as I was personal around for this from 1969-1979.  As Amateur Radio Ham Radio was in the family 60's-70's (WN8QGF 1965-1966)WA8UNS (1966-1971) -WB4WZR (1971 until recently changed) And my mother was WN8QGE 1965-1966. As with this my Amateur Radio Ham Radio FCC call sign is WA8UNS





I grew up with Drake Amateur Radio Equipment, R. L. Drake Company manufacturer of electronic communications and also KDK 2 meter FM transceiver mobile in the 1970's My father also used a  Vibroplex Bug.,

As WA8UNS was my father's call sign in which changed in 1971 with a 4 call. The Drake Amateur Radio Equipment was sold before we moved to Paris, France in 1984. From 1979-1984 I would be able to build some small kits from Heathkit like a Code Oscillator HD-1416 Morse Heathkit Brand, Heath Co.; Benton Harbor MI and a few others. 



My Fathers old vibroplex morse code keyer mid 60's-70's WN8QGF-WA8UNS ( 1965-1971 ) -WB4WZR ( 1971 until recently changed )


I am also a Army and Navy Brat as my father was a US Army Signal Corps Officer with the US Army Security Agency Support Group out of Ft Meade, Md. We had a TDY at Ft Hood, TX  December 1969 through May 1970 for MASSTER US Army Project Mobile Army Sensor System Test Evaluation and Review Surveillance, Target Acquisition and Night Observation STANO.  On October 17, 1969, Project MASSTER moved to Building 91025 at the newly designated West Fort Hood, formerly "Killeen Base.”

I believe after some research that Colonel Sammy J. Cannon, SigC was one of my father’s bosses at US Army Project Mobile Army Sensor System Test Evaluation and Review Surveillance, Target Acquisition and Night Observation STANO

Major General John K. Singlaub was the chief of staff, Project MASSTER US Mobile Army Sensor System Test Evaluation and Review Surveillance, Fort Hood, Texas, Oct 69 - Jun 71. 


Major General John K. Singlaub chief of staff, Project MASSTER, Fort Hood,



Many thanks to Major General John K. Singlaub for having sent this autographed picture to me. It really means a lot to me. As I was at home while my father was working under you there at US Army Project MASSTER US Army Project Mobile Army Sensor System Test Evaluation And Review STANO Surveillance, Target Acquisition and Night Observation. I believe my father was with the Communications/Navigation Branch As he was a US Army Signal Corps Officer with the US Army Security Agency Support Group
December 1969 through May 1970 apart of military history to me. Wish I could meet you in person one day and shake your hand. Thank You for your service


I had one day in the early 1990's like 1990 found this book on Major General John Kirk Singlaub Major General John Kirk Singlaub Hazardous Duty An American Soldier In The Twentieth Century  I look in it at the index and photos and came across Project MASSTER. So it became an intresting read to me. 


As my interest in my father’s military past grew as I was around for most of it July 1969-1979 10 years I wanted so research why his first activity duty TDY at Ft Hood, TX  December 1969 through May 1970 for MASSTER US Mobile Army Sensor System Test Evaluation and Review SurveillanceTarget Acquisition and Night Observation STANO. In which Major General John Singlaub was the chief of staff, Project MASSTER, Fort Hood, Texas, Oct 69 - Jun 71. ? As my father prior to this was doing mostly for the Office Of Naval Research ONR Cooley Electronics Laboratory Department of Electrical Engineering The University of Michigan Ann Arbor, Michigan. So a few years of researching came up with US Army Security Agency Support Group had a presence there but also maybe the part of SurveillanceTarget Acquisition and Night Observation STANO. Had some involvement with Operation Igloo White Sensors and Weapons which has mentioned U.S. Navy's Project Jezebel  replacing the hydrophones with microphones. But all is just a research theory for me. A book that caught my interest is Wiring Vietnam: The Electronic Wall - Anthony J. Tambini, Wiring Vietnam The Electronic Wall.pdf - Higher Intellect | Conte

Please click HERE THE FIELD ARTILLERYMAN - Fort Sill - U.S. Army  to see Sensor Systems Studied in Project MASSTER




Then we went back to Ft Meade for the National Security Agency NSA  May 1970-71 as a Cryptanalysis 



Some good reading

Attack on the USS Liberty by William D. Gerhard  Gerhard, William D. Attack on the USS Liberty: An Edited Version of SRH-256. Walnut Creek, CA: Aegean Park, 1996.

Secret and Urgent: The Story of Codes and Ciphers. 
Fletcher Pratt. Aegean Park Press, Apr 1, 1996 

The Origin and Development of the National Security Agency (Cryptographic Series) [ George Brownell, Wayne G. Barker] ( Laguna Hills, CA: Aegean Park Press, 1981)


The Origin and Development of the Army Security Agency 1917-1947. Laguna Hills, CA: Aegean Park Press, June 1, 1993



Movie from Top secret NSA by Discovery Channel 4 5 

  



My old 1980's passport DDR Deutsche Demokratische Republik  East Germany from 1986 Zarrentin to Staaken, Again when the familiy was pulled over didn't know anything about my father's military past.,, 


US Army Security Agency Support Group Fort George G Meade Maryland 
Awards and Decorations Ceremony Service Club #2 1400 Hours 30 September 1970






Thomas Q Kimball WA8UNS visiting the NSA National Cryptologic Museum - NSA/CSS The Memorial Wall  "They Served in Silence,"2006


National Cryptologic Memorial - NSA/CSS - National Security Agency






The little guy in the crib is Thomas Q Kimball

My father was in Signal Officer Basic Course, Ft Gordon June through August 1969 but came back to Ann Arbor, Michigan to see my birth July 4th 1969. Wish I could  see a class picture photo from the Signal Officer Basic Course, Ft Gordon June through August 1969 

I became interested in areas of subjects that where related to my growing up with my father's military past and also Amateur Radio Ham Radio as I was born in  July 1969 at the The University of Michigan Hospital  Ann Arbor, Michigan. So I was around for his Army two-year active duty which included US Army Signal Corps Officer with the US Army Security Agency Support Group out of Ft Meade, Md. We had a TDY at Ft Hood, TX December 1969 through May 1970 for MASSTER US Mobile Army Sensor System Test Evaluation and Review SurveillanceTarget Acquisition and Night Observation STANO As it reads from the website masster - 1969-1976 - OTC History

On October 17, 1969, Project MASSTER moved to Building 91025 at the newly designated West Fort Hood, formerly "Killeen Base."and also Ft Meade for the National Security Agency NSA R Group - Research and Engineering. May 1970-71 as a Cryptanalysis . After that we moved to Miami, Fla for the ONR Office Of Naval Research 71-79. The work for ONR Office of Naval Research took my father to US Naval Facility NAVFAC Eleuthera and NAVFAC Bermuda.


I did not know any of my father's work from 1969-1979.  And really didn't learn anything of it until mid to late 1980's.  But did find his old Vietnam Era OG-107 Uniforms in which I had found in box's and would wear the shirts when hiking.


#WA8UNS @WA8UNS #ThomasQuickKimball #ThomasKimball #ridgefieldct #Ridgefield @ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut Thomas Q Kimball of Ridgefield, Connecticut wanted to share The Arizona Communications Unit Leader (COML) Best Practices Guide. Impressed that it has all the ICS Forms needed for a Communications Unit Leader (COML) in one pdf document. Even though it says Arizona I’m sure it can be used and adopted to use in any state. 
To get to the Arizona Communications Unit Leader (COML) Best Practices Guide please goto the OEC Public Safety Tools Website and look for the PS Library (Public Safety Library Box ) you can type it in the search box.

#WA8UNS @WA8UNS #ThomasQuickKimball #ThomasKimball #ridgefieldct #Ridgefield @ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut Thomas Q Kimball of Ridgefield, Connecticut wanted to share The Newly Released NIFOG 1.6.1 The Newly Released National Interoperability Field Operations Guide v1.6.1 June 2016


Please click here to see more about 

#WA8UNS @WA8UNS #ThomasQuickKimball #ThomasKimball #ridgefieldct #Ridgefield @ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut Thomas Q Kimball of Ridgefield, Connecticut wanted to share his perspective and personal thoughts between TRG-RADO All-Hazard Radio Operator (RADO) Training and the TRG-AUXCOMM Auxiliary Communications Workshop
for Amateur Radio Operators Ham Radio Operators and what would be more beneficial. As for most Amateur Radio Ham Radio Operators work during the week and to get the time to take a COML, COMT and TRG-AUXCOMM Auxiliary Communications Workshop is hard as for the most part only have a weekend to take a class course. And now out there is the TRG-RADO All-Hazard Radio Operator (RADO) Training out there.


Please click here to see more about 


As seen in the above

The Communications Unit (COMU) Plays a critical support within the Incident Command System (ICS). ICS establishes basic principal, practical tools and a definitive nomenclature and structure for supporting incident-based emergency response. 

The Communications Unit Leader (COML) heads the Communications Unit and is responsible for integrating communications and ensuring that operations are supported by communications. The COML must understand ICS and local response systems to support efforts of Incident personnel. 

Please click here to see 

Under the Communications Unit Training has subjects of the following:

Roles & Responsibilities of COMU Personnel
COML Course Development
COML Course Delivery
AuxComm and COMT Courses
Train-the-Trainer Courses
Position Task Books (PTBs)

Under Roles & Responsibilities of COMU Personnel Mentions the Communications Unit (particularly the COMT, INCM and RADO), were originally developed by the National Wildfire Coordinating Group (NWCG)


DHS/OEC/ICTAP Incident Command System (ICS) Communications Unit (COMU) Implementation and Best Practices Mentions the
History of NIMS ICS All-Hazards Communications Unit. Mentions:
Since the late 1970’s Wildland Fire Incident Management Teams. 
Also mentions:
Following the events of September 11, 2001 a Presidential Executive Order required all significant events to use the National Incident Management System (NIMS) 

As seen in my blog below:
We talk and discussed The History of ICS in which came from Firescope
(Firefighting Resources of California Organized for Potential Emergencies). 
Below are some links from articles I had come across about the above including the U.S Coast Guard ICS adoption and Homeland Security Presidential Directive-5 and NIMS (9/11) mentioned in one of the articles. 

Please click here to see 


Please click here to see 

The Fires that created an Incident Management System

Please click here to see 


National All-Hazards Communications Unit Leader COML Mobilization Guide (This is like a template to add information to)


Please click here to see 


DHS/OEC/ICTAP Communications Unit (COMU) Positions Description Recognized in the Incident Command System (ICS) Notice Amateur Radio Operators in the above chart. Amateur Radio Operators and AUXCOMM members support the COM-L as a Technical Specialist (THSP)



The ICS organizational chart with IC- Incident Commander LSC-Logistics Section Chief COML- Communications Unit Leader.
#WA8UNS @WA8UNS #ThomasQuickKimball #ThomasKimball #ridgefieldct #Ridgefield @ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut wanted to share he has completed The NIMS ICS All-Hazards Incident Commander Course January 27th-31st 2014
 #WA8UNS @WA8UNS #ThomasQuickKimball #ThomasKimball #ridgefieldct #Ridgefield @ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut wanted to share he has completed The NIMS ICS All-Hazards Logistics Section Chief June 2nd-6th 2014

#WA8UNS @WA8UNS #ridgefieldct #Ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut Thomas Q Kimball of Ridgefield, Connecticut wanted to share he has successfully completed The NIMS ICS All-Hazards Communications Unit Leader Course (E/L-0969) 


Courses like the Radio Operator (RADO) J-158 have been out there in the NWCG NFES Radio Operator (RADO) J-158 have been out there for years. 
Please click here to see more about 

You will find Radio Operator (RADO) in the above: 
A Complex Organizational Chart 
From The Office of Emergency Communications (OEC) 
The Communications Unit (COMU) Overview Part 2

As you can see by looking at The Technical Assistance & Statewide Communications Interoperability Plan (SCIP) Catalog Department of Homeland Security Office Of Emergency Communications Version 4.1 under the course description for TRG-RADO: All-Hazard Radio Operator Training it reads Available in Spring 2015 
FEMA DHS has adopted a lot from the Wildland Fire Community.

Also the same with The Incident Communications Center Manager J-257 have been out there in the NWCG NFES  Incident Communications Center Manager J-257  have been out there for years. 

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As you can see by looking at The Technical Assistance & Statewide Communications Interoperability Plan (SCIP) Catalog Department of Homeland Security Office Of Emergency Communications Version 4.1 under the course description for TRG-INCM: Incident Communications Center Manager Training  INCM Available in Spring 2015 


Available in Spring 2015

This class provides hands-on and lecture based training for the All-Hazard ICS RADO position. It introduces public safety professionals and support personnel to various Radio Operator concepts including radio etiquette, interoperable communications, dispatch operations and emergency communications procedures. Participants develop the essential core competencies used during incident response and planned events to perform the duties of the RADO in an all-hazards environment including communications support for public safety, wildfire, marine, aviation and HF radio communications. The responsibilities of an All-Hazard RADO can include staffing the Incident Communications Center, monitoring radio traffic, and base station operations for emergency operations centers, hospitals, dispatch centers and non-governmental organizations supporting civil emergency response at the state, local or regional level. 

This course is taught by OEC/ICTAP instructors who have both dispatch and communications unit experience. The course provides a realistic, hands-on approach to mastering the tasks and skills of an All-Hazards Radio Operator. It is designed for emergency response professionals and support personnel in all disciplines who have a basic understanding of the all-hazard ICS communications unit. 

This course is two days long. It provides a position task book and hands on exercises for each attendee.
Prerequisites & Other Information:
Prerequisites for attendance are:

Awareness of fundamental public safety communications technology.
Completion of the OEC Communications Unit Awareness web-based course11 (Not required at this time until available)
Completion of IS-100.b, IS-200.b, IS-700.a, and IS-800.b
ICS-300, Intermediate Incident Command System (ICS) for Expanding Incidents, is also recommended.




The All-Hazards Communications Unit Self-Paced Briefing PPT to find this goto the OEC Public Safety Tools Website Under Training and then hit the COMU Overview button and look for COMU Awareness

* Radio Operator (RADO)
Three day course introduces public safety professional and support personnel to various Radio Operator concepts including radio etiquette, interoperable communications, dispatch operations and emergency communications procedures. 

** Noticed a discrepancy with the info here reading it's a Three day course and the information in the Technical Assistance & Statewide Communications Interoperability Plan (SCIP) Catalog Department of Homeland Security Office Of Emergency Communications Version 4.1 is mentioning it's a This course is two days long. **

* Auxiliary Communications (AUXCOMM)
Two day workshop familiarizes  amateur radio operators and others to support an incident communications center, emergency operations center, hospital and/or public safety emergency response entities.

** More information Video's about Auxiliary Communications (AUXCOMM) can be seen at the OEC Public Safety Tools Website Under Training and then hit the COMU Overview button but here is direct link AUXCOMM Overview **
So some folks out there might think that the All-Hazards Radio Operator (RADO) Position Task Book Version 1.1 January 2016 is a course within it's self and just came out as reads Version 1.1 January 2016 as it clearly doesn't mention and or clearly mark that you would have to complete the two day TRG-RADO - All-Hazard Radio Operator Training first. Also some might think that all they have to do is have somebody check them off on the  All-Hazards Radio Operator (RADO) Position Task Book and that is all you have to do. As some folks might browse through the OEC Public Safety Tools Website and look for the PS Library (Public Safety Library Box ) by clicking this you can then search in the webview 

For the Position Task Book (PTB) Process in which is normally the next step in the process after completing the class room training. 


As seen above 
Important Note: Training requirements include completion of all required training courses prior to obtaining a PTB (Position Task Book). Use of the suggested training courses or job aids is recommended to prepare the employee to perform in the position. 

Position Task Books are an integral part of the "performance-based” system Federal agencies have adopted for emergency response training.

If you goto the OEC Public Safety Tools Website and look for the PS Library (Public Safety Library Box ) 

More About:
Under the title POSITION TASK BOOK (PTB) DESIGN AND USE

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Below is a NWCG National Wildfire Coordination Group Task Book for the Position of Radio Operator (RADO) PMS 311-97 Dated June 2009. As what I think is taking along time to understand that FEMA Department of Homeland Security has adopted this as well as other NIMS ICS All-Hazards Courses from Firescope and Wildfire Community.

We talk and discussed The History of ICS in which came from Firescope
(Firefighting Resources of California Organized for Potential Emergencies). 
Below are some links from articles I had come across about the above including the U.S Coast Guard ICS adoption and Homeland Security Presidential Directive-5 and NIMS (9/11) mentioned in one of the articles. 

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Below is a NWCG National Wildfire Coordination Group Communications Unit Leader S-358 Student Workbook dated September 2001

Communications Unit Leader S-358 Student Workbook NFES 1928 September 2001 

I was able to able to obtain a pdf version in a previous course class I had


TRG-AUXCOMM: Auxiliary Emergency Communications Course Certificate

Auxiliary Emergency Communicator (AUXCOMM) – This unofficial ICS position supports the operational and technical aspects of the Auxiliary Communications Unit, maintains and/or operates the AUXCOMM network; the knowledge to perform this function applies to every AUXCOMM position

I had attended the DESPP Sponsored Auxiliary Emergency Communications AEC Workshop At the CT Fire Academy on May 3rd and May 4th 2014

Our instructors where and many thanks to them

Carter Davis (KH6FV)  From Honolulu. Hawaii HIDHS/Office of Emergency Communications Honolulu

Chris Baker  ( KF6CDV ) Battalion Chief/Paramedic with the Roseville CA Fire Department. Department of Homeland Security COML and COMT instructor.

Thomas Q Kimball looking at the STOC (State Tactical On-Scene) boxes  "Spring Training" A Grand Slam in Connecticut QST; Jul 2009, Vol. 93 Issue 7, p70 ( Mr. Wilson Photo Credit )

WA8UNS listening to a briefing on the State Tactical Scene Communication Box STOC Interoperability Solution Model 341 Communications Gear made by Marcus Communications for the State of Connecticut Office of Emergency Management Department of Emergency Management and Homeland Security .



Connecticut, State Tactical On-Scene Channel System (STOCS) Train the Trainer Certificate

WA8UNS Thomas Q Kimball of Ridgefield, Connecticut taking part in the The State Tactical On-Scene Channel System (STOCS)  is to provide an Interoperable Radio System for on scene tactical use. Train the Trainer Training that took place here at Ridgefield, Connecticut this morning. Great day for this on April 12th 2014 







Thomas Q Kimball of Ridgefield, Connecticut  WA8UNS ARES Amateur Radio Emergency Service 2007 Identification.

CT REGION 5 Connecticut Amateur Radio Emergency Service (CT ARES) Radio Amateur Civil Emergency (RACES) CT ARES District 5



WA8UNS Member of ARES Amateur Radio Emergency Service KX1EOC Danbury, Connecticut



Thomas Q Kimball of Ridgefield, Connecticut WA8UNS Member of both the CARA Candlewood Amateur Radio Association and PEARL Putnam Emergency Amateur Repeater League 


#WA8UNS @WA8UNS #ThomasQuickKimball #ThomasKimball #ridgefieldct #Ridgefield @ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut Thomas Q Kimball of Ridgefield, Connecticut wanted to share he has taken
The ARRL Amateur Radio Emergency Communications Course ARECC Level 1 March 27th 2007 This is my old FCC Call Sign KB1MJF Before I had switched to WA8UNS.


#WA8UNS @WA8UNS #ThomasQuickKimball #ThomasKimball #ridgefieldct #Ridgefield @ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut Thomas Q Kimball of Ridgefield, Connecticut wanted to share he has taken The Connecticut Emergency Communications Spring Training March 28th 2009 Southbury, CT Connecticut Amateur Radio Service ARES Connecticut CT REGION 5 Connecticut Amateur Radio Emergency Service (CT ARES)


#WA8UNS @WA8UNS #ridgefieldct #Ridgefield in #FairfieldCounty #FairfieldCountyCT #CT #Connecticut Thomas Q Kimball of Ridgefield, Connecticut wanted to share he has successfully completed The NIMS ICS All-Hazards Communications Unit Leader Course (E/L-0969) that was held at Orange County Department Of Emergency Services, Goshen, New York. The Orange County Emergency Services Center Goshen, NY On July 12-14th 2016. Many thanks to Chris Carney Communications System Specialist Orange County Department of Emergency Services for hosting this event. All Many thanks to our two instructors Keith Victor of The Department of Homeland Security (DHS) Office of Emergency Communications (OEC) and Toby Dusha NYS Division of Homeland Security and Emergency Services NYS Office of Interoperable & Emergency Communications.
And assisting Richard Claing CT IMT-3 And nice to have in our class Brett Chellis, Deputy Director of the Office of Interoperable and Emergency Communications and others from Connecticut like Town of Ridgefield Ed Briggs Director of Health and some folks from New Jersey. 



In above picture Thomas Q Kimball of Ridgefield, Connecticut with Keith Victor of The Department of Homeland Security (DHS) Office of Emergency Communications (OEC) and Toby Dusha NYS Division of Homeland Security and Emergency Services NYS Office of Interoperable & Emergency Communications.


In picture Thomas Q Kimball of Ridgefield, Connecticut with The Ulster County Sheriff's Office Mobile Incident Command Vehicle. Nice to have a couple guys from The Ulster County Sheriff's Office bring it to class and show us there truck with all the nice communications set up and portable repeater. 



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The United States Coast Guard Communications Unit Activities Communications Unit Leader "P" aka Planning P Please see video below of the ICS Planning P Cycle


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OEC Public Safety Tools Website and look for the PS Library (Public Safety Library Box) by clicking this you can then search in the webview under the area search you will see Connecticut and that is where you will find the Connecticut Interoperability Field Operations Guide (CTIFOG) CT FOG v1.0

As seen in the Connecticut Interoperability Field Operations Guide (CTIFOG) CT FOG v1.0 
Radio Operator (RADO)

Staffs a radio at the ICC and is responsible for documenting incoming radio and telephone messages. Incident Dispatchers or Tactical Dispatchers are used as RADOs.



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The above shows and or tells you about each communications course out there by giving you a description and also letting you know what the Prerequisites are. 


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 As seen in The Auxiliary. Communications Field Operations Guide (AUXFOG) US Department of Homeland Security Office of Emergency Communications Version 1.0. at 1.2.4 Radio Operator (RADO)
1. Staff positions in the ICC
2. Responsible for documenting radio and telephone messages.
3. Incident Dispatchers, Tactical Dispatchers, Telecommunicator Emergency Response Taskforce (TERT) team members many be assigned to RADO positions by the COML
4. RADOs, Incident Dispatchers, Tactical Dispatchers, and TERT team members typically receive specialized training to operate in an incident-based environment. 

I'm am not sure if a Amateur Radio Ham Radio Operator would want to do the above. 

Auxiliary Communications Field Operations Guide (AUXFOG) US Department Of Homeland Security Office Of Emergency Communications Version 1.0. In it’s index includes Basic ICS Organization - Communications Unit Position Descriptions - ICS Roles And Responsibilities And ICS Forms and more.


I was able to obtain this New York City Interagency Communications Committee  NYCICC
New York City Urban Area Radio Interoperability Field Operations Guide from one of  courses I had attended.

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I had a old pdf version of The National Incident Radio Support Cache User's Guide 2003 National Interagency Incident Communications National Interagency Fire Center a file that was handed out in one of my many previous courses that I have attended. I just recently found a 2015 version. In this mentions COMT COML like a COML/COMT Checklist ICS-205 Radio Communications Plan

#WA8UNS @WA8UNS #ridgefieldct #Ridgefield in #FairfieldCounty #CT  Thomas Q Kimball of Ridgefield, Connecticut  wanted to share :


Questions I have seen on google.

How did September 11th change my life.  How has your life changed since 9/11? How did the attacks of 9/11 change your life?

#NeverForget911

Since The activation Task Force Liberty, the New York Guard Component of the 42nd Joint Task Force Rainbow Hope activated for Operation World Trade Center. And leaving with New York Guard with Honorable Discharge July 31 2003. In some of the training I have received from people that where there at Ground Zero WTC on 9/11 in which an honor to be taught by them. I’m glad to have made these accomplishments in my training which has been continuous, as it’s always evolving in Emergency Management. Some of my training might follow some of the recommendations from the 


“Create dedicated, ongoing training programs for FDNY chiefs so that they are proficient in using ICS principles during large and complex incidents involving terrorism, chemical, biological and radiological materials, and attacks to critical infrastructure.”

 Thomas Q Kimball WA8UNS with The New York Guard State Volunteer Force At Camp Smith Training Site HHC, Army Division Enlisted in the New York Guard 29 April 2000 ETS April 2003  Promoted Staff Sergeant E-6 15 March 2003 Honorable Discharge July 31 2003 Rank Grade SSG/E6 NYG World Trade Center Incident
#nyguard #newyorkguard #campsmith @newyorkguard

 A Certificate of Special Recognition The New York Guard Operation World Trade Center at Camp Smith Training Site apart of The New York Guard  MP Detachment 



I had just found this below in a storage
42nd Joint Task Force Rainbow Hope

Joint Task Force 42 Rainbow Hope

An Open Letter to JTF 42 Service Members Brigadier General Joseph J Taluto Joint Task Force Commander

Synopsis of NYG ARDIV Duty Assignments, Task Force New York City and Task Force Liberty, 9/11/01 to 1/10/02 as seen in The Guardian Issue # 02-1 June 2002

At the time of The New York Guard activation Task Force Liberty, the New York Guard Component of the 42nd Joint Task Force Rainbow Hope activated for Operation World Trade Center. At Camp Smith Training Site we were at Threatcon Charlie FPCON CHARLIE  apart of The New York Guard  MP Detachment we where unarmed while working there at Camp Smith Training Site  Cortlandt Manor near Peekskill, NY, New York Guard Awards and Decorations include: New York State Defense of Liberty Medal 15 September 2002, as well as the New York Guard Commander’s Citation 15 August 2002



From my old historical file:  Military Police Unit Headquarters 
New York Guard Army Division
Camp Smith
Newsletter
29 June 00

Under #6 Training A self study book is a available to all MP’s on responding to terrorism. 

The book FEMA/USFA/NFA-ERT:SS June 1999
Emergency Response To Terrorism Self-Study U.S Department of Justice Office of Justice Programs-Bureau of Justice Assistance Federal Emergency Management Agency United States Fire Administration-National Fire Academy



As seen in Fire Engineering: first responders' first line of defense in terrorism responses by Sam Hansen and Alan Veasey. This article mentions how The federal Emergency Response to Terrorism Job Aid, which is intended to be used with the Department of Transportation (DOT) Emergency Response Guidebook (ERG)

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Please see link below to read article written by Kenneth O. Burris Jr. as appeared in Fire Engineering 10/01/2000

Please see link below:



From my old historical file:  Military Police Unit Headquarters 
New York Guard Army Division
Camp Smith
Newsletter

1 April 00

Under #5 Training Up date on Peace Officer Training, will be held at Camp Smith on 29 & 30 April, 6 May, 20 & 21 May.


Thomas with the two New York Guard Peace Officer Training Instructors.


New York Guard State Volunteer Force At Camp Smith Training Site Building 504 Peace Officer Training Group Photo. The training was April 29th and 30th and May 6th, 20th and 21st 2000 Thomas is in photo last row on the side of entry to building. Also in photo back row is friend Paul Garre also from Connecticut.


Then it was a must to get and have for the class and or course was the Penal Law and Criminal Procedure Law of the State of New York. For the New York Guard for the Peace Officer Training for the Military Police Unit Headquarters New York Guard.



From my old historical file:
NYSG-COS (3025) Members Of The New York Guard
World Trade Center (9*11) Survey
Operation Trade Center and Operation Airport Security Member Survey-State of New York

The New York Guard MP Detachment  Securing Camp Smith Training Site Pre New York Army National Guard MP Shack at Camp Smith Training Site Cortlandt Manor near Peekskill, NY, after 9/11 WTC Incident






Night time operations The New York Guard MP Detachment  Securing Camp Smith Training Site at Camp Smith Training Site Cortlandt Manor near Peekskill, NY, after 9/11 WTC Incident


In photo with New York State Police trooper Kevin Reppenhagen Camp Smith Training Site Cortlandt Manor near Peekskill, NY, after 9/11 WTC Incident


The New York Guard Military Police Station Provost Marshal Building 85 Camp Smith Training Site Cortlandt Manor near Peekskill, NY,  after 9/11 WTC Incident


The New York Guard Military Police Vehicle Camp Smith Training Site Cortlandt Manor near Peekskill, NY,  after 9/11 WTC Incident


New York Guard State Volunteer Force At Camp Smith Training Site NYG World Trade Center Incident Duty Group Photo. 

A small group of The New York Guard MP Detachment was sent to due some NYG World Trade Center Incident Duty at the New York Army National Guard and the Westchester County Police Academy in Valhalla, NY