Pub Date : 1994-10-02DOI: 10.1109/MILCOM.1994.473920
S. V. Pizzi, D. Gess, M. L. Morrissette
In this report we determine the global data rate capabilities of geosynchronous commercial communications satellites for United States Navy communications. We focus on the use of C-band and K/sub u/-band links, since these frequency bands are the primary frequency bands used by commercial satellites. To determine the data rates, we divide the Earth's surface into contiguous regions, use generic link budgets, and consider 38 currently orbiting and 11 planned commercial geosynchronous satellites. C-band coverage is available on an almost worldwide basis. The available C-band data rates for most of the ocean areas are well under 1 Mb/s even when planned satellites are considered. For coastal and continental areas, there are a number of regions which can provide data rates of 1 Mb/s or greater. K/sub u/-band coverage is available on a limited global basis; however, re-pointing of some K/sub u/-band beams is possible and could provide coverage in regions where no coverage is presently available. We do not consider re-pointing of the beams in this study. For those regions which have either full or partial coverage, the K/sub u/-band data rates are, in general, much greater than 1 Mb/s.<>
{"title":"Global data rate capabilities of geosynchronous commercial satellites for United States Navy communications","authors":"S. V. Pizzi, D. Gess, M. L. Morrissette","doi":"10.1109/MILCOM.1994.473920","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473920","url":null,"abstract":"In this report we determine the global data rate capabilities of geosynchronous commercial communications satellites for United States Navy communications. We focus on the use of C-band and K/sub u/-band links, since these frequency bands are the primary frequency bands used by commercial satellites. To determine the data rates, we divide the Earth's surface into contiguous regions, use generic link budgets, and consider 38 currently orbiting and 11 planned commercial geosynchronous satellites. C-band coverage is available on an almost worldwide basis. The available C-band data rates for most of the ocean areas are well under 1 Mb/s even when planned satellites are considered. For coastal and continental areas, there are a number of regions which can provide data rates of 1 Mb/s or greater. K/sub u/-band coverage is available on a limited global basis; however, re-pointing of some K/sub u/-band beams is possible and could provide coverage in regions where no coverage is presently available. We do not consider re-pointing of the beams in this study. For those regions which have either full or partial coverage, the K/sub u/-band data rates are, in general, much greater than 1 Mb/s.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127910851","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.473989
C. Coleman
A propagation model for HF radiowave systems is presented. The model is based on an efficient 2D ray tracing algorithm and an ionosphere that is derived from well known models such as IRI and FAIM. Calculations of Doppler shift, Doppler spread and signal loss are included to allow for a wide variety of uses. Some sample applications are included.<>
{"title":"A propagation model for HF radiowave systems","authors":"C. Coleman","doi":"10.1109/MILCOM.1994.473989","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473989","url":null,"abstract":"A propagation model for HF radiowave systems is presented. The model is based on an efficient 2D ray tracing algorithm and an ionosphere that is derived from well known models such as IRI and FAIM. Calculations of Doppler shift, Doppler spread and signal loss are included to allow for a wide variety of uses. Some sample applications are included.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121355296","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.473825
P. D. Anderson, M. A. Ingram, J. S. Goldstein
The effects of correlated interference on narrowband adaptive arrays are reviewed. The performance of the spatial smoothing technique, used in a generalized sidelobe canceler with the least mean squares algorithm, is examined in terms of weight misadjustment, mean squared error, and signal-to-noise ratio. One method of combining the algorithm with spatial smoothing is shown to obey a set of nonhomogeneous dynamical equations. A numerical example is presented to support the analysis.<>
{"title":"The performance of spatial smoothing techniques using the LMS algorithm","authors":"P. D. Anderson, M. A. Ingram, J. S. Goldstein","doi":"10.1109/MILCOM.1994.473825","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473825","url":null,"abstract":"The effects of correlated interference on narrowband adaptive arrays are reviewed. The performance of the spatial smoothing technique, used in a generalized sidelobe canceler with the least mean squares algorithm, is examined in terms of weight misadjustment, mean squared error, and signal-to-noise ratio. One method of combining the algorithm with spatial smoothing is shown to obey a set of nonhomogeneous dynamical equations. A numerical example is presented to support the analysis.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128930594","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.473856
G. Chapelle
A partially coherent detector for continuous phase modulation with a cochannel CW jammer is analysed. Improved bit error rate performance of the partially coherent detector over the noncoherent detector in a CW jamming environment is shown. The investigation identifies the dependence of performance on the modulation index variation versus the interference power-to-signal power ratio. The selection of the optimum modulation index to achieve the minimum probability of bit error while experiencing cochannel CW jamming is discussed.<>
{"title":"Enhanced CW jammer mitigation using partially coherent CPM reception","authors":"G. Chapelle","doi":"10.1109/MILCOM.1994.473856","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473856","url":null,"abstract":"A partially coherent detector for continuous phase modulation with a cochannel CW jammer is analysed. Improved bit error rate performance of the partially coherent detector over the noncoherent detector in a CW jamming environment is shown. The investigation identifies the dependence of performance on the modulation index variation versus the interference power-to-signal power ratio. The selection of the optimum modulation index to achieve the minimum probability of bit error while experiencing cochannel CW jamming is discussed.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128801993","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.473972
L. P. Clare, J. E. Baker, A. Sastry
A new method of code allocation in code division multiple access is proposed that is particularly efficient in meeting multicasting needs, based on the concept of partitioned information 'classes' (CDMA-IC). Transmitters choose spreading codes based on the types of messages they are transmitting, and receivers listen to codes corresponding to the types of messages they are interested in. The performance of this approach can exceed that of both the traditional receiver-directed codes or broadcast codes in environments where there are several multicast groups (in which a given message is of interest to more than one node). Performance is further enhanced when receivers can simultaneously attempt to correlate multiple spreading codes. In a previous paper the authors (see IEEE Military Communications Conference (MILCOM), p.556-560, Boston, October 1993) demonstrated the superiority of CDMA-IC over receiver-directed CDMA and broadcasting, using simulation of some preliminary concepts of the scheme. In this paper, we describe a broader theoretical framework considering such attributes as priorities, relevance and 'value' of the messages, in which the CDMA-IC scheme scheme could be tailored for different scenarios and could be parameterized appropriately.<>
{"title":"A new CDMA scheme for multicasting using information classes","authors":"L. P. Clare, J. E. Baker, A. Sastry","doi":"10.1109/MILCOM.1994.473972","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473972","url":null,"abstract":"A new method of code allocation in code division multiple access is proposed that is particularly efficient in meeting multicasting needs, based on the concept of partitioned information 'classes' (CDMA-IC). Transmitters choose spreading codes based on the types of messages they are transmitting, and receivers listen to codes corresponding to the types of messages they are interested in. The performance of this approach can exceed that of both the traditional receiver-directed codes or broadcast codes in environments where there are several multicast groups (in which a given message is of interest to more than one node). Performance is further enhanced when receivers can simultaneously attempt to correlate multiple spreading codes. In a previous paper the authors (see IEEE Military Communications Conference (MILCOM), p.556-560, Boston, October 1993) demonstrated the superiority of CDMA-IC over receiver-directed CDMA and broadcasting, using simulation of some preliminary concepts of the scheme. In this paper, we describe a broader theoretical framework considering such attributes as priorities, relevance and 'value' of the messages, in which the CDMA-IC scheme scheme could be tailored for different scenarios and could be parameterized appropriately.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128438481","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.474015
L.F. Stark, J. Scholl
The AT&T Worldwide Intelligent Network is the largest in the world and contains approximately 2.75 billion circuit miles of transmission facilities; more than 130 digital switches; the world's largest data packet switched network used for call set up and advanced services; and the most advanced network management tools in existence. The basic architecture for the switched portion of the network is comprised of a number of various hardware and software components. AT&T has based its planning on basic principles which are aimed at assuring the reliability of its network as well as the ability to promptly restore traffic for its customers in the event of an outage. These principles fall into four categories: prevention, flexible switching capabilities, facilities restoration, and repair of damaged facilities and/or equipment.<>
{"title":"AT&T Worldwide Intelligent Network: reliability, restoration, and special survivability initiatives","authors":"L.F. Stark, J. Scholl","doi":"10.1109/MILCOM.1994.474015","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.474015","url":null,"abstract":"The AT&T Worldwide Intelligent Network is the largest in the world and contains approximately 2.75 billion circuit miles of transmission facilities; more than 130 digital switches; the world's largest data packet switched network used for call set up and advanced services; and the most advanced network management tools in existence. The basic architecture for the switched portion of the network is comprised of a number of various hardware and software components. AT&T has based its planning on basic principles which are aimed at assuring the reliability of its network as well as the ability to promptly restore traffic for its customers in the event of an outage. These principles fall into four categories: prevention, flexible switching capabilities, facilities restoration, and repair of damaged facilities and/or equipment.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128758197","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.473952
R.B. Mouedin, P. Young
The Army's Enterprise Strategy focuses on identifying, supplying, and implementing sophisticated information and other C4I technologies needed to support the army warfighter. This new land combat doctrine emphasizes mobility, increased operational tempo, and C2OTM (command and control on the move); requiring networks to dynamically respond to continuously changing node topology to digitize the battlefield. Communication support must be provided for "seamless" computer-to-computer data exchange across multiple command layers. Based upon previously published work in the area of tactical networks, Unisys Communication Systems is developing a wireless battlefield tactical networking capability that will provide a high capacity, robust, LPE, and A/J tactical communications network specifically addressing the computer-to-computer data exchange problem in the "on-the-move" environment. This paper reports on this ongoing effort, building upon move than six years of previous work-both customer funded and IR&D.<>
{"title":"Wireless battlefield tactical networking supporting C2OTM and C4I for the army warrior","authors":"R.B. Mouedin, P. Young","doi":"10.1109/MILCOM.1994.473952","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473952","url":null,"abstract":"The Army's Enterprise Strategy focuses on identifying, supplying, and implementing sophisticated information and other C4I technologies needed to support the army warfighter. This new land combat doctrine emphasizes mobility, increased operational tempo, and C2OTM (command and control on the move); requiring networks to dynamically respond to continuously changing node topology to digitize the battlefield. Communication support must be provided for \"seamless\" computer-to-computer data exchange across multiple command layers. Based upon previously published work in the area of tactical networks, Unisys Communication Systems is developing a wireless battlefield tactical networking capability that will provide a high capacity, robust, LPE, and A/J tactical communications network specifically addressing the computer-to-computer data exchange problem in the \"on-the-move\" environment. This paper reports on this ongoing effort, building upon move than six years of previous work-both customer funded and IR&D.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117259947","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.473859
F. Xiong, M. Saoud
Convolutionally coded DPSK MBC system is analyzed based on the time-varying SNR model and the statistical nature of the burst duration and the decaying time constant. The performance is evaluated in terms of the average bit error rate, the throughput, the average waiting time, and the system complexity. The average bit error rate is stressed in this paper, whereas only maximum acceptable BER is used as a parameter in earlier literature. The results obtained by this method are more accurate than that by the classical methods. The new results are about 1 dB more optimistic in terms of minimum SNR. The performance of the CC-DPSK is compared with that of a Reed-Solomon coded-DPSK. It shows that for similar performance the CC-DPSK has a much smaller system complexity and for similar complexity the soft-decision decoded CC-DPSK has a much better performance.<>
{"title":"Application of convolutionally coded DPSK in meteor-burst communication systems","authors":"F. Xiong, M. Saoud","doi":"10.1109/MILCOM.1994.473859","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473859","url":null,"abstract":"Convolutionally coded DPSK MBC system is analyzed based on the time-varying SNR model and the statistical nature of the burst duration and the decaying time constant. The performance is evaluated in terms of the average bit error rate, the throughput, the average waiting time, and the system complexity. The average bit error rate is stressed in this paper, whereas only maximum acceptable BER is used as a parameter in earlier literature. The results obtained by this method are more accurate than that by the classical methods. The new results are about 1 dB more optimistic in terms of minimum SNR. The performance of the CC-DPSK is compared with that of a Reed-Solomon coded-DPSK. It shows that for similar performance the CC-DPSK has a much smaller system complexity and for similar complexity the soft-decision decoded CC-DPSK has a much better performance.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115656796","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.473892
S. Sheth, F. Harris
In conventional receivers, carrier recovery and timing recovery are performed in the analog domain by controlling the frequency and phase of voltage controlled oscillators (VCO) in their respective phase locked loop (PLL). When the control signal for these loops are generated in the sampled data domain by DSP techniques the digital samples must be brought to the analog domain by a pair of digital-to-analog converters (DAC). It is more cost effective to perform the entire signal processing function of the PLL in the digital domain and avoid the cost of the DAC and analog smoothing filter in the processing loops. In the full DSP implementation the receiver performs an initial complex down conversion with an asynchronous local oscillator set to the nominal final conversion frequency and then absorbs the residual carrier and phase uncertainty by data dependent control of a digital complex rotator. In a similar fashion sample timing is performed by the sampling the input signal with an asynchronous sampling clock operating at nominally twice the symbol rate and then absorbs residual frequency and phase of the sampling clock by resampling the data with a polyphase filter bank.<>
{"title":"Timing and carrier recovery techniques in DSP based digital receivers","authors":"S. Sheth, F. Harris","doi":"10.1109/MILCOM.1994.473892","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473892","url":null,"abstract":"In conventional receivers, carrier recovery and timing recovery are performed in the analog domain by controlling the frequency and phase of voltage controlled oscillators (VCO) in their respective phase locked loop (PLL). When the control signal for these loops are generated in the sampled data domain by DSP techniques the digital samples must be brought to the analog domain by a pair of digital-to-analog converters (DAC). It is more cost effective to perform the entire signal processing function of the PLL in the digital domain and avoid the cost of the DAC and analog smoothing filter in the processing loops. In the full DSP implementation the receiver performs an initial complex down conversion with an asynchronous local oscillator set to the nominal final conversion frequency and then absorbs the residual carrier and phase uncertainty by data dependent control of a digital complex rotator. In a similar fashion sample timing is performed by the sampling the input signal with an asynchronous sampling clock operating at nominally twice the symbol rate and then absorbs residual frequency and phase of the sampling clock by resampling the data with a polyphase filter bank.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116152577","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.473830
H. Akhtar
This paper discusses some of the simulation modeling techniques for future ATM/BISDN enterprise networks being developed at AT&T GIS and AT&T Bell Labs which could be applied to network architectures involving banks, insurance companies, retail businesses, private networks, etc. to provide global information solutions. A brief overview of ATM and analytical modeling techniques for ATM is presented. This is then followed by an illustration of simulation modeling using OPNET, one of the state-of-the-art simulation packages. OPNET was chosen as the tool of choice for ATM networking due its unique ability, to date, to easily conduct state-diagram modeling in a hierarchical environment and also due to its inherent ability to provide an open interface to such proven analytical tools as MATLAB, QTK, QUEUE, M/G/1/N+1, GI/M/N+1 and proprietary internal AT&T Bell Labs tools such as PAT, Q SQUARED, MYPAL, QNA, PANACEA, TRAFFCALC, etc., which will be needed to do some of the cross-checking of the simulations.<>
{"title":"Modeling and simulation of ATM/BISDN enterprise networks","authors":"H. Akhtar","doi":"10.1109/MILCOM.1994.473830","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473830","url":null,"abstract":"This paper discusses some of the simulation modeling techniques for future ATM/BISDN enterprise networks being developed at AT&T GIS and AT&T Bell Labs which could be applied to network architectures involving banks, insurance companies, retail businesses, private networks, etc. to provide global information solutions. A brief overview of ATM and analytical modeling techniques for ATM is presented. This is then followed by an illustration of simulation modeling using OPNET, one of the state-of-the-art simulation packages. OPNET was chosen as the tool of choice for ATM networking due its unique ability, to date, to easily conduct state-diagram modeling in a hierarchical environment and also due to its inherent ability to provide an open interface to such proven analytical tools as MATLAB, QTK, QUEUE, M/G/1/N+1, GI/M/N+1 and proprietary internal AT&T Bell Labs tools such as PAT, Q SQUARED, MYPAL, QNA, PANACEA, TRAFFCALC, etc., which will be needed to do some of the cross-checking of the simulations.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114111804","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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