Pub Date : 1982-10-01DOI: 10.1109/MILCOM.1982.4805935
S. Glisic
An analysis of error probability for noncoherent demodulation of spread spectrum signals using charge - coupled devices is presented. Average error probability for SSK-DS-SS (Sequence Shift-keying DS-SS), IQ-DS-SS (In Phase + Quadrature DS-SS), IIQ-DS-SS (Improved IQ-DS-SS) and DDIQ-DS-SS (Differential Data IQ-DS-SS) system is derived.
本文分析了电荷耦合器件对扩频信号进行非相干解调时的误差概率。推导了SSK-DS-SS (Sequence shift -key DS-SS)、IQ-DS-SS (In Phase + Quadrature DS-SS)、IIQ-DS-SS (Improved IQ-DS-SS)和DDIQ-DS-SS (Differential Data IQ-DS-SS)系统的平均误差概率。
{"title":"Noncoherent Demodulation of Spread Spectrum Signals using Charge Coupled Devices","authors":"S. Glisic","doi":"10.1109/MILCOM.1982.4805935","DOIUrl":"https://doi.org/10.1109/MILCOM.1982.4805935","url":null,"abstract":"An analysis of error probability for noncoherent demodulation of spread spectrum signals using charge - coupled devices is presented. Average error probability for SSK-DS-SS (Sequence Shift-keying DS-SS), IQ-DS-SS (In Phase + Quadrature DS-SS), IIQ-DS-SS (Improved IQ-DS-SS) and DDIQ-DS-SS (Differential Data IQ-DS-SS) system is derived.","PeriodicalId":179832,"journal":{"name":"MILCOM 1982 - IEEE Military Communications Conference - Progress in Spread Spectrum Communications","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126513675","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 : 1982-10-01DOI: 10.1109/MILCOM.1982.4805942
T. Seay
Theoretical bounds are given for the number and length of hopping patterns with a guaranteed maximum number of pairwise hits. Constructions for hopping pattern sets which achieve the single hit bounds are given, as well as hopping patterns which guarantee the maximum number of pairwise hits in the presence of time or frequency asynchrony, or both. It is shown that variable rate coding permits "averaging" of the worst case interference compared to fixed rate coding, when the data messages are of varying duration.
{"title":"Hopping Patterns for Bounded Mutual Interference in Frequency Hopping Multiple Access","authors":"T. Seay","doi":"10.1109/MILCOM.1982.4805942","DOIUrl":"https://doi.org/10.1109/MILCOM.1982.4805942","url":null,"abstract":"Theoretical bounds are given for the number and length of hopping patterns with a guaranteed maximum number of pairwise hits. Constructions for hopping pattern sets which achieve the single hit bounds are given, as well as hopping patterns which guarantee the maximum number of pairwise hits in the presence of time or frequency asynchrony, or both. It is shown that variable rate coding permits \"averaging\" of the worst case interference compared to fixed rate coding, when the data messages are of varying duration.","PeriodicalId":179832,"journal":{"name":"MILCOM 1982 - IEEE Military Communications Conference - Progress in Spread Spectrum Communications","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126602200","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 : 1982-10-01DOI: 10.1109/MILCOM.1982.4805992
E. Ha, D. Chang, B. Forman
The Hughes experimental multiple-element adaptive array antenna system is based on a hybrid implementation of Widrow's LMS algorithm. A microcomputer samples the analog correlator outputs, then computes the new antenna weight settings and updates the quadrature weighting circuitries accordingly. A hard limiter placed in the feedback path prevents permanent capture by the strongest interference. This configuration appears to circumvent the difficulty in nulling against multiple interferences. Laboratory results demonstrate up to 60 dB cancellation of jammers in a few hundred iterations. System performance degrades to about 30 dB suppression for a 12 percent bandwidth jammer.
{"title":"Adaptive Array with Limiter in Feedback Path Preliminary Results","authors":"E. Ha, D. Chang, B. Forman","doi":"10.1109/MILCOM.1982.4805992","DOIUrl":"https://doi.org/10.1109/MILCOM.1982.4805992","url":null,"abstract":"The Hughes experimental multiple-element adaptive array antenna system is based on a hybrid implementation of Widrow's LMS algorithm. A microcomputer samples the analog correlator outputs, then computes the new antenna weight settings and updates the quadrature weighting circuitries accordingly. A hard limiter placed in the feedback path prevents permanent capture by the strongest interference. This configuration appears to circumvent the difficulty in nulling against multiple interferences. Laboratory results demonstrate up to 60 dB cancellation of jammers in a few hundred iterations. System performance degrades to about 30 dB suppression for a 12 percent bandwidth jammer.","PeriodicalId":179832,"journal":{"name":"MILCOM 1982 - IEEE Military Communications Conference - Progress in Spread Spectrum Communications","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127075717","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 : 1982-10-01DOI: 10.1109/MILCOM.1982.4806014
D. Behrman, W. C. Fifer
The goal of the Low Cost Packet Radio (LPR) Program funded by DARPA, via a contract through CECOM, Contract No. DAAK80-81-C-0213, and being developed by Hazeltine Corporation, is a packet radio unit with low cost, low weight, low volume, low power, and high reliability. The LPR consists of a digitally controlled spread spectrum radio and a microprocessor acting as a packet switch. It is to be used in support of experiments with large packet radio networks. The radio utilizes direct-sequence, spread-spectrum techniques using MSK modulation. A code-changeable, SAW matched filter is employed. It is followed by a decision-directed, SAW fading memory filter to provide synchronization, multipath accumulation, and demodulation reference functions. Two data transmission rates are provided at 100 kbps or 400 kbps. In order to improve the reliability of the network links, a convolutional encoder/sequential decoder with forward-error correction capability at three code rates has been incorporated. To achieve an undetected BER of 10-12, CRC is employed for both encoded and uncoded modes of operation. Besides the RF data link, the LPR provides an input/output data link at either low or high speed. The microprocessor system architecture has been optimized to maximize its bus bandwidth.
{"title":"A Low-Cost Spread-Spectrum Packet Radio","authors":"D. Behrman, W. C. Fifer","doi":"10.1109/MILCOM.1982.4806014","DOIUrl":"https://doi.org/10.1109/MILCOM.1982.4806014","url":null,"abstract":"The goal of the Low Cost Packet Radio (LPR) Program funded by DARPA, via a contract through CECOM, Contract No. DAAK80-81-C-0213, and being developed by Hazeltine Corporation, is a packet radio unit with low cost, low weight, low volume, low power, and high reliability. The LPR consists of a digitally controlled spread spectrum radio and a microprocessor acting as a packet switch. It is to be used in support of experiments with large packet radio networks. The radio utilizes direct-sequence, spread-spectrum techniques using MSK modulation. A code-changeable, SAW matched filter is employed. It is followed by a decision-directed, SAW fading memory filter to provide synchronization, multipath accumulation, and demodulation reference functions. Two data transmission rates are provided at 100 kbps or 400 kbps. In order to improve the reliability of the network links, a convolutional encoder/sequential decoder with forward-error correction capability at three code rates has been incorporated. To achieve an undetected BER of 10-12, CRC is employed for both encoded and uncoded modes of operation. Besides the RF data link, the LPR provides an input/output data link at either low or high speed. The microprocessor system architecture has been optimized to maximize its bus bandwidth.","PeriodicalId":179832,"journal":{"name":"MILCOM 1982 - IEEE Military Communications Conference - Progress in Spread Spectrum Communications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130883787","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 : 1982-10-01DOI: 10.1109/MILCOM.1982.4806005
P. Sass
The Army is currently developing a variety of ground based tactical communications systems intended to support the needs of the soldier on the automated battlefield of the 1990's. These new systems employ wideband digital techniques to support requirements for speed and volume of data transfer, and have turned to spread spectrum for the Anti-jam (AJ) protection required for survivability under the electronic warfare threat anticipated over the next twenty years. This paper surveys the essential technical characteristics of CECOM's current spread spectrum system developments for ground-to-ground communications, explains their historical and technical evolution, and explores the underlying rationale for selection of Frequency Hopping (FH) versus Direct Sequence (DS) spread spectrum techniques in each case. Observations and future directions conclude the paper.
{"title":"Army Spread Spectrum - Evolution or Revolution","authors":"P. Sass","doi":"10.1109/MILCOM.1982.4806005","DOIUrl":"https://doi.org/10.1109/MILCOM.1982.4806005","url":null,"abstract":"The Army is currently developing a variety of ground based tactical communications systems intended to support the needs of the soldier on the automated battlefield of the 1990's. These new systems employ wideband digital techniques to support requirements for speed and volume of data transfer, and have turned to spread spectrum for the Anti-jam (AJ) protection required for survivability under the electronic warfare threat anticipated over the next twenty years. This paper surveys the essential technical characteristics of CECOM's current spread spectrum system developments for ground-to-ground communications, explains their historical and technical evolution, and explores the underlying rationale for selection of Frequency Hopping (FH) versus Direct Sequence (DS) spread spectrum techniques in each case. Observations and future directions conclude the paper.","PeriodicalId":179832,"journal":{"name":"MILCOM 1982 - IEEE Military Communications Conference - Progress in Spread Spectrum Communications","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134270216","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 : 1982-10-01DOI: 10.1109/MILCOM.1982.4806021
A. A. Castro
This paper presents and discusses different approaches available to provide uplink protection to high data rate Users of an EHF satellite communication system, by combining temporal spreading gain with the spatial filtering of a spacecraft adaptive nulling antenna. The generalized performance of different nulling approaches is analyzed, as well as the limitations for simultaneously achieving high resolution over large field of view and wide bandwidth, when multiple Users access the satellite.
{"title":"Uplink Antenna Nulling for High Data Rate EHF Satellite Communications","authors":"A. A. Castro","doi":"10.1109/MILCOM.1982.4806021","DOIUrl":"https://doi.org/10.1109/MILCOM.1982.4806021","url":null,"abstract":"This paper presents and discusses different approaches available to provide uplink protection to high data rate Users of an EHF satellite communication system, by combining temporal spreading gain with the spatial filtering of a spacecraft adaptive nulling antenna. The generalized performance of different nulling approaches is analyzed, as well as the limitations for simultaneously achieving high resolution over large field of view and wide bandwidth, when multiple Users access the satellite.","PeriodicalId":179832,"journal":{"name":"MILCOM 1982 - IEEE Military Communications Conference - Progress in Spread Spectrum Communications","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116436186","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 : 1982-10-01DOI: 10.1109/MILCOM.1982.4806025
J. Bartow
In 1981 CECOM placed four contracts for the exploratory development of ECCM techniques which are to be considered for use in a new digital microwave radio development. A spread spectrum modem is under development which will operate in the 4.4 to 5.0 GHz band. The modem will also be designed to operate, with minor changes, in the 14.4 to 15.35 GHz range. The modulation techniuqe selected is offset quadriphase shift keying. A hybrid direct sequence/frequency hopping system is being designed. The data rates at which the modems are expected to operate are related to various TRI-TAC and DCS multiplexers. Input data rates will vary from 72 kbps to 4.608 in the 4.4-5.0 GHz band and from 72 kbps to 18.720 Mbps in the 14.4-15.35 GHz band. The modulation and frequency translation schemes will be discussed. A steerable null antenna system will be designed for both RF bands and fabricated for C-band. The objective of this antenna is to discriminate against unwanted signals arriving in its side lobes and in the main beam. Among the requirements and constraints which will affect the antenna design are the need for duplex operation, the necessity for installation of the antenna on a 100 foot tactical mast, and the requirement to operate with high output power levels. A coding equipment development is underway which will result in the fabrication of an error correction technique to correct random errors and bursts of errors in the modem output.
{"title":"Digital Microwave Radio Program","authors":"J. Bartow","doi":"10.1109/MILCOM.1982.4806025","DOIUrl":"https://doi.org/10.1109/MILCOM.1982.4806025","url":null,"abstract":"In 1981 CECOM placed four contracts for the exploratory development of ECCM techniques which are to be considered for use in a new digital microwave radio development. A spread spectrum modem is under development which will operate in the 4.4 to 5.0 GHz band. The modem will also be designed to operate, with minor changes, in the 14.4 to 15.35 GHz range. The modulation techniuqe selected is offset quadriphase shift keying. A hybrid direct sequence/frequency hopping system is being designed. The data rates at which the modems are expected to operate are related to various TRI-TAC and DCS multiplexers. Input data rates will vary from 72 kbps to 4.608 in the 4.4-5.0 GHz band and from 72 kbps to 18.720 Mbps in the 14.4-15.35 GHz band. The modulation and frequency translation schemes will be discussed. A steerable null antenna system will be designed for both RF bands and fabricated for C-band. The objective of this antenna is to discriminate against unwanted signals arriving in its side lobes and in the main beam. Among the requirements and constraints which will affect the antenna design are the need for duplex operation, the necessity for installation of the antenna on a 100 foot tactical mast, and the requirement to operate with high output power levels. A coding equipment development is underway which will result in the fabrication of an error correction technique to correct random errors and bursts of errors in the modem output.","PeriodicalId":179832,"journal":{"name":"MILCOM 1982 - IEEE Military Communications Conference - Progress in Spread Spectrum Communications","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117074477","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 : 1982-10-01DOI: 10.1109/MILCOM.1982.4805906
H. Ochsner
The effect of certain time-variant channels on the performance of a PN spread-spectrum system is analyzed without assuming perfect synchronization of the receiver's PN sequence. The results show that maximizing the power of the despread signal can be markedly suboptimal concerning the signal-to-noise ratio and that even well-known tracking loops may exhibit only moderate performance.
{"title":"Analysis of Pseudo-Noise Spread-Spectrum Communication over Randomly Time-Variant Channels Without Assuming Perfect Synchronization","authors":"H. Ochsner","doi":"10.1109/MILCOM.1982.4805906","DOIUrl":"https://doi.org/10.1109/MILCOM.1982.4805906","url":null,"abstract":"The effect of certain time-variant channels on the performance of a PN spread-spectrum system is analyzed without assuming perfect synchronization of the receiver's PN sequence. The results show that maximizing the power of the despread signal can be markedly suboptimal concerning the signal-to-noise ratio and that even well-known tracking loops may exhibit only moderate performance.","PeriodicalId":179832,"journal":{"name":"MILCOM 1982 - IEEE Military Communications Conference - Progress in Spread Spectrum Communications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115572398","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 : 1982-10-01DOI: 10.1109/MILCOM.1982.4805925
K. Natarajan, D. Walters, B. Maglaris
We address the problem of designing a circuit-switched network for voice communications operating in a military environment. The circuit-switched network design problem may be briefly stated as: given the topology, route tables and control discipline, end-to-end offered traffic and performance requirements, determine trunk group sizes such that the requirements are satisfied. One of the key requirements of a design is that the network be survivable, where survivability is based on different destruction scenario conditions. Our objective is to guarantee an acceptable level of performance for every node pair and under each of the different anticipated damage scenarios. The main contributions of our present work are the development of approaches for designing networks that simultaneously satisfy performance requirements for different destruction scenarios. We describe the architecture of a survivable, circuit-switched network. The key characteristics of the survivable network design problem are highlighted and differences with respect to classical trunk sizing problem are pointed out. An important aspect of our work is that the sizing is based on the logical topology of the network rather than its trunk group topology. One design approach, which we have used successfully, is presented in detail.
{"title":"Design of Survivable Circuit-Switched Communication Networks","authors":"K. Natarajan, D. Walters, B. Maglaris","doi":"10.1109/MILCOM.1982.4805925","DOIUrl":"https://doi.org/10.1109/MILCOM.1982.4805925","url":null,"abstract":"We address the problem of designing a circuit-switched network for voice communications operating in a military environment. The circuit-switched network design problem may be briefly stated as: given the topology, route tables and control discipline, end-to-end offered traffic and performance requirements, determine trunk group sizes such that the requirements are satisfied. One of the key requirements of a design is that the network be survivable, where survivability is based on different destruction scenario conditions. Our objective is to guarantee an acceptable level of performance for every node pair and under each of the different anticipated damage scenarios. The main contributions of our present work are the development of approaches for designing networks that simultaneously satisfy performance requirements for different destruction scenarios. We describe the architecture of a survivable, circuit-switched network. The key characteristics of the survivable network design problem are highlighted and differences with respect to classical trunk sizing problem are pointed out. An important aspect of our work is that the sizing is based on the logical topology of the network rather than its trunk group topology. One design approach, which we have used successfully, is presented in detail.","PeriodicalId":179832,"journal":{"name":"MILCOM 1982 - IEEE Military Communications Conference - Progress in Spread Spectrum Communications","volume":"30 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123587647","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 : 1982-10-01DOI: 10.1109/MILCOM.1982.4805934
R. Lunayach, Sunir Kochhar
In this paper performance of a spread spectrum system with a large number of network terminals and a small number of network control terminals is addressed. Network control terminals carry out most functions relating acquisitions, synchronization, control and aid network terminals. Network response times are calculated for various aiding stratagies and the conditions for a stable network operation are derived. Analytical results are verified with the help of simulations carried out using simulation language SLAM.
{"title":"Network Response Times of a Spread Spectrum System with Large Number of Network Terminals and Central Control","authors":"R. Lunayach, Sunir Kochhar","doi":"10.1109/MILCOM.1982.4805934","DOIUrl":"https://doi.org/10.1109/MILCOM.1982.4805934","url":null,"abstract":"In this paper performance of a spread spectrum system with a large number of network terminals and a small number of network control terminals is addressed. Network control terminals carry out most functions relating acquisitions, synchronization, control and aid network terminals. Network response times are calculated for various aiding stratagies and the conditions for a stable network operation are derived. Analytical results are verified with the help of simulations carried out using simulation language SLAM.","PeriodicalId":179832,"journal":{"name":"MILCOM 1982 - IEEE Military Communications Conference - Progress in Spread Spectrum Communications","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114822343","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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