Pub Date : 1964-09-01DOI: 10.1109/TSET.1964.4335601
A. Viterbi, C. Cahn
The optimum phase-locked loop demodulator is obtained for a carrier, phase modulated by a stationary Gaussian modulating process whose spectrum is proportional to 1/1 + (f/B)2n where n is any positive integer. Results are obtained also when the carrier is frequency modulated by the process for the limiting cases n = 1 and as n approaches infinity. It is shown that for phase modulation the output SNR as a function of the channel SNR in the bandwidth B varies from linear to exponential behavior as n increases from 1 to ∞. For the limiting cases the performance of frequency modulation is slightly inferior to that for phase modulation.
{"title":"Optimum Coherent Phase and Frequency Demodulation of a Class of Modulating Spectra","authors":"A. Viterbi, C. Cahn","doi":"10.1109/TSET.1964.4335601","DOIUrl":"https://doi.org/10.1109/TSET.1964.4335601","url":null,"abstract":"The optimum phase-locked loop demodulator is obtained for a carrier, phase modulated by a stationary Gaussian modulating process whose spectrum is proportional to 1/1 + (f/B)2n where n is any positive integer. Results are obtained also when the carrier is frequency modulated by the process for the limiting cases n = 1 and as n approaches infinity. It is shown that for phase modulation the output SNR as a function of the channel SNR in the bandwidth B varies from linear to exponential behavior as n increases from 1 to ∞. For the limiting cases the performance of frequency modulation is slightly inferior to that for phase modulation.","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1964-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128719472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1964-09-01DOI: 10.1109/TSET.1964.4335600
B. R. Davis
A signal dependent threshold condition is often observed in feedback FM detectors. It is shown in this paper that this is due to the shape of the discriminator characteristic, and that in general a great deal of care is needed in discriminator design in order to reduce this effect.
{"title":"Factors Affecting the Threshold of Feedback FM Detectors","authors":"B. R. Davis","doi":"10.1109/TSET.1964.4335600","DOIUrl":"https://doi.org/10.1109/TSET.1964.4335600","url":null,"abstract":"A signal dependent threshold condition is often observed in feedback FM detectors. It is shown in this paper that this is due to the shape of the discriminator characteristic, and that in general a great deal of care is needed in discriminator design in order to reduce this effect.","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1964-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121692329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1964-09-01DOI: 10.1109/TSET.1964.4335602
J. Gibson
Manual patching of large quantities of circuits requires considerable time, and is difficult to verify and awkward to change. The system described herein is an automatic patchboard capable of making 480 (or less) connections rapidly. Connections are made between two-wire inlets and outlets in any combination, and are controlled from a preprogrammed punched tape or from manual operation of a keyset on a control console. By departing from standard straight forward techniques in switching and control, a reliable nonblocking automatic patchboard became economically feasible.
{"title":"A Nonblocking Switching System for Programmed Telemetry Control","authors":"J. Gibson","doi":"10.1109/TSET.1964.4335602","DOIUrl":"https://doi.org/10.1109/TSET.1964.4335602","url":null,"abstract":"Manual patching of large quantities of circuits requires considerable time, and is difficult to verify and awkward to change. The system described herein is an automatic patchboard capable of making 480 (or less) connections rapidly. Connections are made between two-wire inlets and outlets in any combination, and are controlled from a preprogrammed punched tape or from manual operation of a keyset on a control console. By departing from standard straight forward techniques in switching and control, a reliable nonblocking automatic patchboard became economically feasible.","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1964-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122796008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1964-09-01DOI: 10.1109/TSET.1964.4335604
M. Kaufman
The Space Surveillance System developed at the U. S. Naval Research Laboratory, Washington, D. C., for the detection of earth satellites forms a fence across the southern part of the United States. Four receiving sites are alternated with three transmitting sites which illuminate satellites with radio energy as they traverse the fence. The angle of arrival of the reflected energy is measured at each receiving station by a compound radio interferometer. These signals yield a multiplicity of channels which are normally recorded on paper, read and resolved by using slide rules and/or mathematical tables. Operationally the resolution is done by a computer. With the increasing satellite population the number of fence crossings has increased considerably. Automation in the detection process is needed to facilitate identification and sorting of satellites from each other if a large backlog of data is to be avoided. The purpose of this report is to describe an electronic system which automatically combines several noisy ambiguous radio interferometer phase channels into one unambiguous quiet channel. This technique results in that given a multi-baseline radio interferometer system, normally having high angular resolution capability accompanied with the usual interferometer ambiguity problem associated with deciphering the multiple phase signal outputs it can be instrumented directly into a single unambiguous signal output which has an accuracy and resolution proportional to the longest baseline in the interferometer and whose noise content is inversely proportional to this baseline.
{"title":"Radio Interferometer Phase-Channel Combiner Mod. II for the Navy Space Surveillance System","authors":"M. Kaufman","doi":"10.1109/TSET.1964.4335604","DOIUrl":"https://doi.org/10.1109/TSET.1964.4335604","url":null,"abstract":"The Space Surveillance System developed at the U. S. Naval Research Laboratory, Washington, D. C., for the detection of earth satellites forms a fence across the southern part of the United States. Four receiving sites are alternated with three transmitting sites which illuminate satellites with radio energy as they traverse the fence. The angle of arrival of the reflected energy is measured at each receiving station by a compound radio interferometer. These signals yield a multiplicity of channels which are normally recorded on paper, read and resolved by using slide rules and/or mathematical tables. Operationally the resolution is done by a computer. With the increasing satellite population the number of fence crossings has increased considerably. Automation in the detection process is needed to facilitate identification and sorting of satellites from each other if a large backlog of data is to be avoided. The purpose of this report is to describe an electronic system which automatically combines several noisy ambiguous radio interferometer phase channels into one unambiguous quiet channel. This technique results in that given a multi-baseline radio interferometer system, normally having high angular resolution capability accompanied with the usual interferometer ambiguity problem associated with deciphering the multiple phase signal outputs it can be instrumented directly into a single unambiguous signal output which has an accuracy and resolution proportional to the longest baseline in the interferometer and whose noise content is inversely proportional to this baseline.","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1964-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116981276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1964-09-01DOI: 10.1109/TSET.1964.4335599
J. C. Balder, C. Kramer
It is shown that normal delta modulation can be used for the transmission of dc signals. A circuit is described in which a delta modulator is combined with a counter for analog-to-digital conversion of a dc signal. Several factors contributing to the accuracy are developed. One of these factors which has not been dealt with previously is the size of the steps in the reconstructed signal due to the finite integrator time constant. Two examples of delta modulators are described; one of them a high precision system, the other a simple design of moderate precision.
{"title":"Analog-to-Digital Conversion by Means of Delta Modulation","authors":"J. C. Balder, C. Kramer","doi":"10.1109/TSET.1964.4335599","DOIUrl":"https://doi.org/10.1109/TSET.1964.4335599","url":null,"abstract":"It is shown that normal delta modulation can be used for the transmission of dc signals. A circuit is described in which a delta modulator is combined with a counter for analog-to-digital conversion of a dc signal. Several factors contributing to the accuracy are developed. One of these factors which has not been dealt with previously is the size of the steps in the reconstructed signal due to the finite integrator time constant. Two examples of delta modulators are described; one of them a high precision system, the other a simple design of moderate precision.","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"420 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1964-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126706786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1964-06-01DOI: 10.1109/TSET.1964.4337569
G. Frenkel
The causes of short-term oscillator instability are discussed. The effects of the instability of the received signal on the phase-locked loop performance are analyzed in terms of resultant mean-squared loop phase error. The results of the analysis permit the calculation of the effects of oscillator instability in the transmitter on the loop bandwidth and power requirement. They also furnish a systematic approach to specifying the oscillator stability requirements.
{"title":"Oscillator Stability and the Second-Order Phase-Locked Loop","authors":"G. Frenkel","doi":"10.1109/TSET.1964.4337569","DOIUrl":"https://doi.org/10.1109/TSET.1964.4337569","url":null,"abstract":"The causes of short-term oscillator instability are discussed. The effects of the instability of the received signal on the phase-locked loop performance are analyzed in terms of resultant mean-squared loop phase error. The results of the analysis permit the calculation of the effects of oscillator instability in the transmitter on the loop bandwidth and power requirement. They also furnish a systematic approach to specifying the oscillator stability requirements.","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1964-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131716051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1964-06-01DOI: 10.1109/TSET.1964.4337570
H. L. Cannon
On the basis of the derived far field of a turnstile antenna rotating about an arbitrary axis, the signal observed at the terminals of a pair of mutually orthogonal receiving dipoles is evaluated. The phase and amplitude of the signals received by a single dipole at two mutually orthogonal orientations and a circularly polarized antenna are determined as special cases. The results indicate that phase discontinuities which might possibly degrade the performance of a phase sensitive receiver may occur if the turnstile rotates about one of its dipoles, assuming a linearly polarized receiving antenna. This is not observed if a circularly polarized receiving antenna is used.
{"title":"Modulation of Signals Received from a Cw Transmitting Turnstile Antenna Due to Its Rotation","authors":"H. L. Cannon","doi":"10.1109/TSET.1964.4337570","DOIUrl":"https://doi.org/10.1109/TSET.1964.4337570","url":null,"abstract":"On the basis of the derived far field of a turnstile antenna rotating about an arbitrary axis, the signal observed at the terminals of a pair of mutually orthogonal receiving dipoles is evaluated. The phase and amplitude of the signals received by a single dipole at two mutually orthogonal orientations and a circularly polarized antenna are determined as special cases. The results indicate that phase discontinuities which might possibly degrade the performance of a phase sensitive receiver may occur if the turnstile rotates about one of its dipoles, assuming a linearly polarized receiving antenna. This is not observed if a circularly polarized receiving antenna is used.","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1964-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129303796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1964-06-01DOI: 10.1109/TSET.1964.4337573
J. Hansen
A number of corrections are noted for the above-named work (ibid., SET-9, pp. 92-98; September, 1963).
注意到对上述工作的一些更正(同上，SET-9，第92-98页;1963年9月)。
{"title":"Correction to \"An integrated 'error-free' communication system\"","authors":"J. Hansen","doi":"10.1109/TSET.1964.4337573","DOIUrl":"https://doi.org/10.1109/TSET.1964.4337573","url":null,"abstract":"A number of corrections are noted for the above-named work (ibid., SET-9, pp. 92-98; September, 1963).","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1964-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120910651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1964-06-01DOI: 10.1109/TSET.1964.4337571
S. Gupta
This paper considers the nonlinearity of the multiplier in the phase-locked loop which is optimized for a frequency ramp input. The third-order system with this nonlinearity is analyzed for transient response. Equilibrium points and stability are considered from eigenvalues, and transient response is determined using norm in phase space vs phase-space variables. The technique of getting error, error derivative, etc., vs time curves is described in great detail. Comparative study is made for the exact linear model, practical linear model and practical nonlinear model.
{"title":"Transient Analysis of a Phase-Locked Loop Optimized for a Frequency Ramp Input","authors":"S. Gupta","doi":"10.1109/TSET.1964.4337571","DOIUrl":"https://doi.org/10.1109/TSET.1964.4337571","url":null,"abstract":"This paper considers the nonlinearity of the multiplier in the phase-locked loop which is optimized for a frequency ramp input. The third-order system with this nonlinearity is analyzed for transient response. Equilibrium points and stability are considered from eigenvalues, and transient response is determined using norm in phase space vs phase-space variables. The technique of getting error, error derivative, etc., vs time curves is described in great detail. Comparative study is made for the exact linear model, practical linear model and practical nonlinear model.","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1964-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125006805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1964-06-01DOI: 10.1109/TSET.1964.4337568
R. Ward
This paper discusses the use of delay-lock radar techniques for deep-space tracking and communications tasks. To illustrate these techniques, a Mars or Venus space probe of the Voyager type is used as a typical mission. The Voyager is an unmanned vehicle in the 6000-lb class which is planned for scientific and exploratory purposes from the years 1967 to 1975. A brief introduction to the results of delay-lock radar development to date is given, followed by a description of the digital delay-lock discriminator. A discussion is then given on the problems inherent in the modulation and demodulation which is required to make full use of the delay-lock capability. An integrated delay-lock two-way tracking-communications system suitable for the assumed mission is then described and the performance to be expected is calculated. This anticipated performance indicates considerable improvement over present capabilities.
{"title":"Application of Delay-Lock Radar Techniques to Deep-Space Tasks","authors":"R. Ward","doi":"10.1109/TSET.1964.4337568","DOIUrl":"https://doi.org/10.1109/TSET.1964.4337568","url":null,"abstract":"This paper discusses the use of delay-lock radar techniques for deep-space tracking and communications tasks. To illustrate these techniques, a Mars or Venus space probe of the Voyager type is used as a typical mission. The Voyager is an unmanned vehicle in the 6000-lb class which is planned for scientific and exploratory purposes from the years 1967 to 1975. A brief introduction to the results of delay-lock radar development to date is given, followed by a description of the digital delay-lock discriminator. A discussion is then given on the problems inherent in the modulation and demodulation which is required to make full use of the delay-lock capability. An integrated delay-lock two-way tracking-communications system suitable for the assumed mission is then described and the performance to be expected is calculated. This anticipated performance indicates considerable improvement over present capabilities.","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"197 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1964-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132912115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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