Pub Date : 1990-05-06DOI: 10.1109/VETEC.1990.110354
T. Iwama, E. Moriyama, H. Ryuko, S. Sekizawa, T. Sarauwatari
Experimental and calculated results of propagation characteristics above 1 GHz for microcellular land mobile radio in an urban area are described. Measurements were made at 1.5 GHz and 2.6 GHz with a fixed antenna located at the side of the road at a height of 5.3 m. Data were taken with an omnidirectional antenna at 2 cm intervals along the measured routes. Tall buildings line the measured routes on both sides. According to the experimental and calculated results, the propagation loss is dominated by interference among the direct ray and specularly, building-reflected and mobile-reflected rays in the line-of-sight propagation environment, and by interference between specular rays and building-diffracted rays in shadowed propagation. Therefore, in line-of-sight propagation, the median of propagation loss is similar to the free-space loss. In shadowed propagation, however, the median is not determined only by the base-to-mobile antenna distance.<>
{"title":"Investigation of propagation characteristics above 1 GHz for microcellular land mobile radio","authors":"T. Iwama, E. Moriyama, H. Ryuko, S. Sekizawa, T. Sarauwatari","doi":"10.1109/VETEC.1990.110354","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110354","url":null,"abstract":"Experimental and calculated results of propagation characteristics above 1 GHz for microcellular land mobile radio in an urban area are described. Measurements were made at 1.5 GHz and 2.6 GHz with a fixed antenna located at the side of the road at a height of 5.3 m. Data were taken with an omnidirectional antenna at 2 cm intervals along the measured routes. Tall buildings line the measured routes on both sides. According to the experimental and calculated results, the propagation loss is dominated by interference among the direct ray and specularly, building-reflected and mobile-reflected rays in the line-of-sight propagation environment, and by interference between specular rays and building-diffracted rays in shadowed propagation. Therefore, in line-of-sight propagation, the median of propagation loss is similar to the free-space loss. In shadowed propagation, however, the median is not determined only by the base-to-mobile antenna distance.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132395429","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 : 1990-05-06DOI: 10.1109/VETEC.1990.110384
S. McGrath, C. Burkley
The design of a reduced-complexity modulator and demodulator using Gaussian minimum shift keying (GMSK) is presented. Both modulator and demodulator follow the European Conference of Postal and Telecommunications Administrations (CEPT), Group Special Mobile (GSM) recommendations. A single ROM modulator circuit and a coherent demodulator using De Buda (1972) clock and carrier techniques are used to give reduced complexity designs. The demodulator is a coherent receiver that uses phase-locked loops in the clock and carrier recovery circuits. Both the modulator and demodulator designs give satisfactory performance at reduced complexity, and are suitable for implementation on silicon.<>
{"title":"Low complexity GMSK modulator and demodulator for integrated circuit implementation","authors":"S. McGrath, C. Burkley","doi":"10.1109/VETEC.1990.110384","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110384","url":null,"abstract":"The design of a reduced-complexity modulator and demodulator using Gaussian minimum shift keying (GMSK) is presented. Both modulator and demodulator follow the European Conference of Postal and Telecommunications Administrations (CEPT), Group Special Mobile (GSM) recommendations. A single ROM modulator circuit and a coherent demodulator using De Buda (1972) clock and carrier techniques are used to give reduced complexity designs. The demodulator is a coherent receiver that uses phase-locked loops in the clock and carrier recovery circuits. Both the modulator and demodulator designs give satisfactory performance at reduced complexity, and are suitable for implementation on silicon.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"248 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115755481","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 : 1990-05-06DOI: 10.1109/VETEC.1990.110325
W. Sobkiw, P. R. Payne
The US Federal Aviation Administration (FAA) is establishing a generation of air-ground communications based on the exchange of digital data. The advantages and disadvantages of the various media are discussed. A comprehensive concept for using the existing FAA voice VHF network for data link operations is developed. This data exchange will be supported by mode-S for continental United States (CONUS) operations and satellite communications (SATCOM) for oceanic operations. The airlines are presently using a digital data link network for airline operations that is a contender for future FAA air traffic control (ATC) data link services.<>
{"title":"Integration of air/ground data links","authors":"W. Sobkiw, P. R. Payne","doi":"10.1109/VETEC.1990.110325","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110325","url":null,"abstract":"The US Federal Aviation Administration (FAA) is establishing a generation of air-ground communications based on the exchange of digital data. The advantages and disadvantages of the various media are discussed. A comprehensive concept for using the existing FAA voice VHF network for data link operations is developed. This data exchange will be supported by mode-S for continental United States (CONUS) operations and satellite communications (SATCOM) for oceanic operations. The airlines are presently using a digital data link network for airline operations that is a contender for future FAA air traffic control (ATC) data link services.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115903156","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 : 1990-05-06DOI: 10.1109/VETEC.1990.110382
J. Cavers, R. F. Marchetto, S. D. Carlson
A novel and very general spectrum shaping code, called look ahead block inversion (LABI), for creating spectral notches of arbitrary width, shape, and location is described. It can trade depth against width and, for a given specification, adds minimum overhead. Uses include protection against AC coupling, tones, or other impairments. When used for pilot tone aided modulation (PTAM), it improves performance compared to previous spectrum shaping codes, though self-noise remains a limitation. The authors extend the investigation of block coding and PTAM with two contributions. First, a novel coding algorithm is introduced which can create notches of arbitrary width, depth, and location by combining an unconventional use of the Viterbi algorithm (VA) at the transmitter with a general distortion criterion based on filtering the data signal. The technique minimizes the fraction of redundant symbols. Second, by simulation, the use of spectrum shaping codes is explored for PTAM, including the effect of self-noise.<>
{"title":"A new spectral notch generator for pilot tone systems","authors":"J. Cavers, R. F. Marchetto, S. D. Carlson","doi":"10.1109/VETEC.1990.110382","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110382","url":null,"abstract":"A novel and very general spectrum shaping code, called look ahead block inversion (LABI), for creating spectral notches of arbitrary width, shape, and location is described. It can trade depth against width and, for a given specification, adds minimum overhead. Uses include protection against AC coupling, tones, or other impairments. When used for pilot tone aided modulation (PTAM), it improves performance compared to previous spectrum shaping codes, though self-noise remains a limitation. The authors extend the investigation of block coding and PTAM with two contributions. First, a novel coding algorithm is introduced which can create notches of arbitrary width, depth, and location by combining an unconventional use of the Viterbi algorithm (VA) at the transmitter with a general distortion criterion based on filtering the data signal. The technique minimizes the fraction of redundant symbols. Second, by simulation, the use of spectrum shaping codes is explored for PTAM, including the effect of self-noise.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124220996","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 : 1990-05-06DOI: 10.1109/VETEC.1990.110315
I. Horikawa, M. Hirono
A multicarrier switching time division multiple access-time domain duplex (TDMA-TDD) radio access suitable for the next generation of digital microcellular telecommunications systems is described. In an interference limited environment improved coexistence between slot asynchronous TDMA systems can be effectively achieved by dynamically allocating TDMA slots and carrier frequencies. Signaling channel allocation is focused on the carrier frequency, which gives the advantage of making possible mobile-controlled hand-over and advanced radio channel control for multicarrier TDMA systems. A traffic rate of 16 kbit/s per channel with a frame length of 1 ms is suitable for diversified applications, such as 32 kbit/s to 8 kbit/s codecs and ISDN services.<>
{"title":"A multi-carrier switching TDMA-TDD microcell telecommunications system","authors":"I. Horikawa, M. Hirono","doi":"10.1109/VETEC.1990.110315","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110315","url":null,"abstract":"A multicarrier switching time division multiple access-time domain duplex (TDMA-TDD) radio access suitable for the next generation of digital microcellular telecommunications systems is described. In an interference limited environment improved coexistence between slot asynchronous TDMA systems can be effectively achieved by dynamically allocating TDMA slots and carrier frequencies. Signaling channel allocation is focused on the carrier frequency, which gives the advantage of making possible mobile-controlled hand-over and advanced radio channel control for multicarrier TDMA systems. A traffic rate of 16 kbit/s per channel with a frame length of 1 ms is suitable for diversified applications, such as 32 kbit/s to 8 kbit/s codecs and ISDN services.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114684046","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 : 1990-05-06DOI: 10.1109/VETEC.1990.110352
P. S. Mundra, T. L. Singal, T. Kamal
A computer algorithm for predicting the service area of a specified percentage of locations that are required to be covered is developed. An empirical formula for performance margin (PM) as a function of frequency (f) and probability of communication (P/sub x/) is derived. This is presented in the form PM=(A+BP/sub x/+Clog P/sub x/) (log f), where A, B, and C are constants depending on frequency and probability of communication. The algorithm enables the determination of the correction factor that must be applied to the range when location probability other than 50% is required. The algorithm can be extended to determine the cochannel interference radius for planning a mobile communication network.<>
{"title":"A computer algorithm for prediction of service area in a mobile radio communication system","authors":"P. S. Mundra, T. L. Singal, T. Kamal","doi":"10.1109/VETEC.1990.110352","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110352","url":null,"abstract":"A computer algorithm for predicting the service area of a specified percentage of locations that are required to be covered is developed. An empirical formula for performance margin (PM) as a function of frequency (f) and probability of communication (P/sub x/) is derived. This is presented in the form PM=(A+BP/sub x/+Clog P/sub x/) (log f), where A, B, and C are constants depending on frequency and probability of communication. The algorithm enables the determination of the correction factor that must be applied to the range when location probability other than 50% is required. The algorithm can be extended to determine the cochannel interference radius for planning a mobile communication network.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116822228","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 : 1990-05-06DOI: 10.1109/VETEC.1990.110318
J. D. Proffitt, J. Cylwik
Techniques for the efficient implementation of cellular cell sites are described. The materials and techniques used to meet the demands of the very difficult Los Angeles market are presented. A number of key attributes were measured regarding the desirability of using various types of cell site buildings. These were as follows: cost, deployment time, deployment flexibility, weight, portability, and sturdiness. As different types of buildings were experimented with and their performance evaluated, it was possible to realize substantial improvements through an evolutionary process which started with concrete block construction in 1984 and moved to the use of modified cargo containers in 1988.<>
{"title":"Rapid deployment custom cell sites","authors":"J. D. Proffitt, J. Cylwik","doi":"10.1109/VETEC.1990.110318","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110318","url":null,"abstract":"Techniques for the efficient implementation of cellular cell sites are described. The materials and techniques used to meet the demands of the very difficult Los Angeles market are presented. A number of key attributes were measured regarding the desirability of using various types of cell site buildings. These were as follows: cost, deployment time, deployment flexibility, weight, portability, and sturdiness. As different types of buildings were experimented with and their performance evaluated, it was possible to realize substantial improvements through an evolutionary process which started with concrete block construction in 1984 and moved to the use of modified cargo containers in 1988.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117193215","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 : 1990-05-06DOI: 10.1109/VETEC.1990.110286
H. Lindenmeier, L. Reiter, J. Hopf, A. Schwab
Modern active AM/FM window antennas and FM-antenna-diversity systems used for cars are described, and a novel type of window antenna is presented. For the antenna diversity system two main problems had to be solved. First, an extremely fast working criterion for FM distortions (noise, multipath distortion, equal channel, adjacent channel, and intermodulation distortion) had to be found. The time required for distortion detection in the realized system is only 25 mu s. In consequence, no audible distortion occurs before the next antenna is switched on. Second, multiantenna systems adequate for modern cars had to be developed. For increased FM performance quality multiantenna diversity systems are used. One of the systems has been implemented in a production by Philips, Fuba, and BMW. It consists of a diversity processor and three narrow-spaced active window antenna arranged in the rear window of BMW type seven and type five cars.<>
{"title":"Multiple FM window antenna system for scanning diversity with an integrated processor","authors":"H. Lindenmeier, L. Reiter, J. Hopf, A. Schwab","doi":"10.1109/VETEC.1990.110286","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110286","url":null,"abstract":"Modern active AM/FM window antennas and FM-antenna-diversity systems used for cars are described, and a novel type of window antenna is presented. For the antenna diversity system two main problems had to be solved. First, an extremely fast working criterion for FM distortions (noise, multipath distortion, equal channel, adjacent channel, and intermodulation distortion) had to be found. The time required for distortion detection in the realized system is only 25 mu s. In consequence, no audible distortion occurs before the next antenna is switched on. Second, multiantenna systems adequate for modern cars had to be developed. For increased FM performance quality multiantenna diversity systems are used. One of the systems has been implemented in a production by Philips, Fuba, and BMW. It consists of a diversity processor and three narrow-spaced active window antenna arranged in the rear window of BMW type seven and type five cars.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117183600","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 : 1990-05-06DOI: 10.1109/VETEC.1990.110369
C. Liu, K. Feher
A novel fade estimation and compensation method based on the pilot symbol insertion (PSI) concept is proposed and analyzed for coherent pi /4-QPSK (quadrature phase shift keying) modems. The estimated fade characteristics are used to compensate the random phase modulation caused by the Doppler spread in a fast Rayleigh fading channel so that the signals can be demodulated coherently. The theoretical performance of the fade compensated coherent modem in a frequency-selective fast Rayleigh fading channel corrupted by additive white Gaussian noise and cochannel interference is evaluated. The results show that the fade compensated coherent demodulation achieves the same performance as noncoherent demodulation in a slow fading channel. The main advantage of the proposed technique is that it removes the error floor caused by Doppler spread in a fast fading channel.<>
{"title":"A new generation of Rayleigh fade compensated pi /4-QPSK coherent modems","authors":"C. Liu, K. Feher","doi":"10.1109/VETEC.1990.110369","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110369","url":null,"abstract":"A novel fade estimation and compensation method based on the pilot symbol insertion (PSI) concept is proposed and analyzed for coherent pi /4-QPSK (quadrature phase shift keying) modems. The estimated fade characteristics are used to compensate the random phase modulation caused by the Doppler spread in a fast Rayleigh fading channel so that the signals can be demodulated coherently. The theoretical performance of the fade compensated coherent modem in a frequency-selective fast Rayleigh fading channel corrupted by additive white Gaussian noise and cochannel interference is evaluated. The results show that the fade compensated coherent demodulation achieves the same performance as noncoherent demodulation in a slow fading channel. The main advantage of the proposed technique is that it removes the error floor caused by Doppler spread in a fast fading channel.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128655899","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 : 1990-05-06DOI: 10.1109/VETEC.1990.110399
D. Kunz
The channel assignment problem (CAP) i.e. the task of assigning the channels to the radio base stations, is an NP-complete optimization problem occurring during design of cellular radio systems. An investigation is carried out to see how far a parallel neural network algorithm may be used for a real-world CAP. The neural network algorithm identified a channel assignment without heuristic rules generating the sequence of channel assignments. Formulating the optimization problems in terms of an energy function turned out to be very flexible, making it easy to include a variety of additional technical constraints and optimization criteria. Since a distinction between hard constraints and soft optimization criteria is only expressed by the relative strength of the terms in the energy function, the user is free to choose this relative strength according to his actual planning situation. Therefore, this neural network algorithm is well suited for the solution of real-world channel assignment problems.<>
{"title":"Practical channel assignment using neural networks","authors":"D. Kunz","doi":"10.1109/VETEC.1990.110399","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110399","url":null,"abstract":"The channel assignment problem (CAP) i.e. the task of assigning the channels to the radio base stations, is an NP-complete optimization problem occurring during design of cellular radio systems. An investigation is carried out to see how far a parallel neural network algorithm may be used for a real-world CAP. The neural network algorithm identified a channel assignment without heuristic rules generating the sequence of channel assignments. Formulating the optimization problems in terms of an energy function turned out to be very flexible, making it easy to include a variety of additional technical constraints and optimization criteria. Since a distinction between hard constraints and soft optimization criteria is only expressed by the relative strength of the terms in the energy function, the user is free to choose this relative strength according to his actual planning situation. Therefore, this neural network algorithm is well suited for the solution of real-world channel assignment problems.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"111 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130807481","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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