Pub Date : 1990-05-06DOI: 10.1109/VETEC.1990.110408
V.S.M. Renduchintala, H. Smith, J. Gardiner, I. Stromberg
An experiment aimed at determining L-band fade statistics for future European land mobile satellite systems is described. During measurement trials, an aircraft was used to simulate a high-elevation orbit satellite whose transmissions were received by a land mobile unit. On the ground, signal-level statistics were measured as a function of two main variables: mobile environment and transmitter-to-receiver elevation angle. Results show that both factors greatly influence the dynamic and temporal nature of fading. Further, data gathered during experiments indicate clearly that, for Northern Europe, propagation problems would be alleviated considerably by using a constellation of highly elevated orbit satellites as opposed to a geostationary alternative.<>
{"title":"Communications service provision to land mobiles in northern Europe by satellites in high elevation orbits-propagation aspects","authors":"V.S.M. Renduchintala, H. Smith, J. Gardiner, I. Stromberg","doi":"10.1109/VETEC.1990.110408","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110408","url":null,"abstract":"An experiment aimed at determining L-band fade statistics for future European land mobile satellite systems is described. During measurement trials, an aircraft was used to simulate a high-elevation orbit satellite whose transmissions were received by a land mobile unit. On the ground, signal-level statistics were measured as a function of two main variables: mobile environment and transmitter-to-receiver elevation angle. Results show that both factors greatly influence the dynamic and temporal nature of fading. Further, data gathered during experiments indicate clearly that, for Northern Europe, propagation problems would be alleviated considerably by using a constellation of highly elevated orbit satellites as opposed to a geostationary alternative.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"32 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":"117030700","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.1990.110307
K. Murakami, M. Shimamura, N. Fujiki
An input interface IC to protect an LSI (such as a microcomputer used in an electronic control unit) from noise, surge, and high-power radio waves occurring at its input line has been developed. This IC has six input-output pairs. Filtering high-power radio waves, radio frequency surge, etc., is the main function of the IC. The IC also includes a level shifter which shifts battery voltage level (12 V) down to LSI level (5 V). This IC needs only one external resistor for each input. The ability to filter various surges and noises is superior than that of conventional input circuit. This IC has a level shift function and input current capacity of more than 1 mA without additional discrete components except for only one resistor/channel. Compared with conventional input circuits consisting of discrete components such as resistors, capacitors, and diodes, etc., this input interface IC offers the advantages of small size and high reliability of the entire electronic control unit.<>
{"title":"Development of a digital input interface IC for automotive electronic control unit","authors":"K. Murakami, M. Shimamura, N. Fujiki","doi":"10.1109/VETEC.1990.110307","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110307","url":null,"abstract":"An input interface IC to protect an LSI (such as a microcomputer used in an electronic control unit) from noise, surge, and high-power radio waves occurring at its input line has been developed. This IC has six input-output pairs. Filtering high-power radio waves, radio frequency surge, etc., is the main function of the IC. The IC also includes a level shifter which shifts battery voltage level (12 V) down to LSI level (5 V). This IC needs only one external resistor for each input. The ability to filter various surges and noises is superior than that of conventional input circuit. This IC has a level shift function and input current capacity of more than 1 mA without additional discrete components except for only one resistor/channel. Compared with conventional input circuits consisting of discrete components such as resistors, capacitors, and diodes, etc., this input interface IC offers the advantages of small size and high reliability of the entire electronic control unit.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"72 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":"114215355","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.1990.110301
T. Fujimoto, M. Mizuno, K. Kanayama
A stable and highly reliable electromagnetic-induction-type vehicle sensor that takes appearance, installation, and maintenance into consideration is developed. It utilizes the electromagnetic coupling of two kinds of ferrite coils. This sensor detects the magnetic field generated by one ferrite coil with the other ferrite coil, and detects the presence of a vehicle from the minute change in the magnetic field generated when the vehicle enters. The installation of the ferrite coils is fairly simple, and this application as other types of sensors can also be considered. The basic principles, configuration of the equipment, and results of experiments on the highly sensitive directional synthesizing system which can sense the minute change in the magnetic field caused by an entering vehicle, and automatically maximize its sensitivity, are discussed. In practical tests, vehicles were satisfactorily detected even when the transmitting and receiving units were installed in the road 3.5 m apart. When installed at the roadside at intervals of one meter, a detection distance of 2.0 m was obtained. These experiments confirmed the ease of installation and the high sensitivity of this sensor.<>
{"title":"Electromagnetic-induction vehicle sensor detecting the gradient of magnetic flux","authors":"T. Fujimoto, M. Mizuno, K. Kanayama","doi":"10.1109/VETEC.1990.110301","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110301","url":null,"abstract":"A stable and highly reliable electromagnetic-induction-type vehicle sensor that takes appearance, installation, and maintenance into consideration is developed. It utilizes the electromagnetic coupling of two kinds of ferrite coils. This sensor detects the magnetic field generated by one ferrite coil with the other ferrite coil, and detects the presence of a vehicle from the minute change in the magnetic field generated when the vehicle enters. The installation of the ferrite coils is fairly simple, and this application as other types of sensors can also be considered. The basic principles, configuration of the equipment, and results of experiments on the highly sensitive directional synthesizing system which can sense the minute change in the magnetic field caused by an entering vehicle, and automatically maximize its sensitivity, are discussed. In practical tests, vehicles were satisfactorily detected even when the transmitting and receiving units were installed in the road 3.5 m apart. When installed at the roadside at intervals of one meter, a detection distance of 2.0 m was obtained. These experiments confirmed the ease of installation and the high sensitivity of this sensor.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"49 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":"128136048","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.1990.110347
L. Jalloul, S. Nanda, David J. Goodman
Packet reservation multiple access (PRMA) allows a group of spatially dispersed terminals to transmit packet voice and data over a common channel. A means to model and evaluate the effects of packet transmission errors on PRMA is developed. PRMA is considered in the context of a cellular system, and the effects of fading on the performance of PRMA are studied. PRMA performance is assessed in terms of system capacity, outage, and cellular efficiency when the transmission channel is subject to slow and fast fading. It is shown that for fast-fading channels simple forward-error correction is sufficient for acceptable system performance. In slow-fading channels, however, other techniques such as selection diversity are required.<>
{"title":"Packet reservation multiple access over slow and fast fading channels","authors":"L. Jalloul, S. Nanda, David J. Goodman","doi":"10.1109/VETEC.1990.110347","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110347","url":null,"abstract":"Packet reservation multiple access (PRMA) allows a group of spatially dispersed terminals to transmit packet voice and data over a common channel. A means to model and evaluate the effects of packet transmission errors on PRMA is developed. PRMA is considered in the context of a cellular system, and the effects of fading on the performance of PRMA are studied. PRMA performance is assessed in terms of system capacity, outage, and cellular efficiency when the transmission channel is subject to slow and fast fading. It is shown that for fast-fading channels simple forward-error correction is sufficient for acceptable system performance. In slow-fading channels, however, other techniques such as selection diversity are required.<<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":"126380096","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.1990.110364
Y. Kamio
A multifrequency channel transmission method for trellis-coded quadrature amplitude modulation (QAM) that uses an interleaving function to improve bit error rate (BER) performance under Rayleigh fading environment conditions is described. A multifrequency channel transmission method for trellis-coded modulation (TCM) that uses interleaving is proposed to distribute the burst error that occurs in the time and frequency domains, and its performance is examined by computer simulation. Computer simulation shows that this method should be useful for land mobile communications.<>
{"title":"Performance of trellis coded modulation using multi-frequency channels in land mobile communications","authors":"Y. Kamio","doi":"10.1109/VETEC.1990.110364","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110364","url":null,"abstract":"A multifrequency channel transmission method for trellis-coded quadrature amplitude modulation (QAM) that uses an interleaving function to improve bit error rate (BER) performance under Rayleigh fading environment conditions is described. A multifrequency channel transmission method for trellis-coded modulation (TCM) that uses interleaving is proposed to distribute the burst error that occurs in the time and frequency domains, and its performance is examined by computer simulation. Computer simulation shows that this method should be useful for land mobile communications.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"11 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":"121841193","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.1990.110370
K. Yamamoto, A. Nakajima
The significant protocol structure of a radio link using the open systems interconnection (OSI) model for a digital mobile communications system is described. The OSI model is applied to this structure for functional expansion of the system. The layer-three part is fundamentally based on the I-interface of the ISDN. There is a special part for the mobile communications system which emphasizes radio frequency efficiency. A technique to reduce the number of signals and the transmission volume is described. The basic procedures and the supplementary service procedures to which this signaling protocol structure is applied are described.<>
{"title":"The signalling protocol structure on the radio link for the digital mobile communications system","authors":"K. Yamamoto, A. Nakajima","doi":"10.1109/VETEC.1990.110370","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110370","url":null,"abstract":"The significant protocol structure of a radio link using the open systems interconnection (OSI) model for a digital mobile communications system is described. The OSI model is applied to this structure for functional expansion of the system. The layer-three part is fundamentally based on the I-interface of the ISDN. There is a special part for the mobile communications system which emphasizes radio frequency efficiency. A technique to reduce the number of signals and the transmission volume is described. The basic procedures and the supplementary service procedures to which this signaling protocol structure is applied are described.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"96 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":"121720929","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.1990.110353
P. Karlsson
An empirical propagation model and the performance of a two-branch macroscopic diversity configuration for indoor microcells are presented. The model is based on measurements made in three different cell types classified according to the indoor environment. Analysis of measured signal strength levels has shown that macroscopic diversity techniques can be used to reduce the link margin for the required 99% area coverage in each cell type. The reduction is dependent of the fading distribution and the maximum achievable rate at which the best path can be selected. The gain with selective macroscopic diversity varies from 4 dB in a cell with high overall propagation attenuation to 10 dB in an open area cell type with lower propagation attenuation. This reduction is obtained when the selections between base stations are made at intervals shorter than 25 cm and the short-fading component is eliminated. The gain can be as high as 12 dB, if all fading is taken into account and the selections are made at intervals shorter than 4 cm.<>
{"title":"Investigation of radio propagation and macroscopic diversity in indoor microcells at 1700 MHz","authors":"P. Karlsson","doi":"10.1109/VETEC.1990.110353","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110353","url":null,"abstract":"An empirical propagation model and the performance of a two-branch macroscopic diversity configuration for indoor microcells are presented. The model is based on measurements made in three different cell types classified according to the indoor environment. Analysis of measured signal strength levels has shown that macroscopic diversity techniques can be used to reduce the link margin for the required 99% area coverage in each cell type. The reduction is dependent of the fading distribution and the maximum achievable rate at which the best path can be selected. The gain with selective macroscopic diversity varies from 4 dB in a cell with high overall propagation attenuation to 10 dB in an open area cell type with lower propagation attenuation. This reduction is obtained when the selections between base stations are made at intervals shorter than 25 cm and the short-fading component is eliminated. The gain can be as high as 12 dB, if all fading is taken into account and the selections are made at intervals shorter than 4 cm.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"45 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":"124948648","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.1990.110391
P. Driessen
900 MHz multipath intensity profiles (impulse response estimates) which may be expected in mountainous terrain are described. Using standard propagation models, it is shown that excess delays greater than 100 mu s may be encountered in scenarios with a line-of-sight path to large scatterers and an obstructed direct path. Possible scenarios in which large excess delays may occur are presented, and two models are proposed. These models are used to predict the channel impulse response that may be expected. Calculated results are presented, and a comparison with measured results in the literature is given. The measurement equipment is briefly described. Such long excess delays are consistent with measured results.<>
{"title":"Measured propagation characteristics of 900 MHz mobile radio channels in mountainous terrain","authors":"P. Driessen","doi":"10.1109/VETEC.1990.110391","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110391","url":null,"abstract":"900 MHz multipath intensity profiles (impulse response estimates) which may be expected in mountainous terrain are described. Using standard propagation models, it is shown that excess delays greater than 100 mu s may be encountered in scenarios with a line-of-sight path to large scatterers and an obstructed direct path. Possible scenarios in which large excess delays may occur are presented, and two models are proposed. These models are used to predict the channel impulse response that may be expected. Calculated results are presented, and a comparison with measured results in the literature is given. The measurement equipment is briefly described. Such long excess delays are consistent with measured results.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"39 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":"131298643","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.1990.110401
A. Narasimhan, S. Chennakeshu, J.B. Anderson
A study of an adaptive decision feedback equalizer (DFE) based on a lattice structure, for application in the US digital cellular radio telephone system, is conducted. The scheme uses a least-squares algorithm that is capable of tracking rapid channel variations. The equalizer exploits the order-recursive nature of the lattice structure to adaptively vary the number of taps, thereby achieving a relatively uniform bit error rate (BER) performance over a wide range of delay spreads. Simulation results illustrate the equalizer's sensitivity to delay spread variation, Doppler shift, and sample timing jitter. Comparisons are made with the performance of a fractionally spaced DFE that uses a complex fast Kalman algorithm. Issues of complexity and finite precision implementation are addressed.<>
{"title":"An adaptive lattice decision feedback equalizer for digital cellular radio","authors":"A. Narasimhan, S. Chennakeshu, J.B. Anderson","doi":"10.1109/VETEC.1990.110401","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110401","url":null,"abstract":"A study of an adaptive decision feedback equalizer (DFE) based on a lattice structure, for application in the US digital cellular radio telephone system, is conducted. The scheme uses a least-squares algorithm that is capable of tracking rapid channel variations. The equalizer exploits the order-recursive nature of the lattice structure to adaptively vary the number of taps, thereby achieving a relatively uniform bit error rate (BER) performance over a wide range of delay spreads. Simulation results illustrate the equalizer's sensitivity to delay spread variation, Doppler shift, and sample timing jitter. Comparisons are made with the performance of a fractionally spaced DFE that uses a complex fast Kalman algorithm. Issues of complexity and finite precision implementation are addressed.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"11 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":"121053128","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.1990.110321
H. Tawfik
Cellular systems where interference is the limiting factor are discussed. In an interference-limited environment, two important system design parameters that directly affect the capacity of the overall system are the minimum carrier to cochannel interference ratio (C/I) and the maximum adjacent channel interference ratio (ACI) the system can tolerate without degrading the speech quality. For these reasons, Northern Telecom has proposed a digital cellular system that is capable of meeting the requirements that were set by members of the Cellular Telecommunication Industry Association (CTIA) for the digital cellular system. Worst-case figures for both C/I and ACI are computed for typical applications for both the forward and the reverse channels, with different reuse patterns, antenna configurations, and terrain. As a result, some frequency planning guidelines for the proper operation of the digital cellular system are presented.<>
{"title":"Frequency planning considerations for digital cellular systems","authors":"H. Tawfik","doi":"10.1109/VETEC.1990.110321","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110321","url":null,"abstract":"Cellular systems where interference is the limiting factor are discussed. In an interference-limited environment, two important system design parameters that directly affect the capacity of the overall system are the minimum carrier to cochannel interference ratio (C/I) and the maximum adjacent channel interference ratio (ACI) the system can tolerate without degrading the speech quality. For these reasons, Northern Telecom has proposed a digital cellular system that is capable of meeting the requirements that were set by members of the Cellular Telecommunication Industry Association (CTIA) for the digital cellular system. Worst-case figures for both C/I and ACI are computed for typical applications for both the forward and the reverse channels, with different reuse patterns, antenna configurations, and terrain. As a result, some frequency planning guidelines for the proper operation of the digital cellular system are presented.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"124 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":"116431146","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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