Pub Date : 1990-05-06DOI: 10.1109/VETEC.1990.110316
T. Kanai, M. Taketsugu, S. Kondo
An experimental digital cellular system composed of a private branch exchange (PBX)-based MSC (mobile switching center), three base stations, two mobile stations, and a radio channel simulator, is developed. The system uses a mobile originated handoff process; i.e. a mobile station requests a handoff to the MSC based on signal strength from surrounding base stations. All control channels are multiplexed on the same carrier so that mobile stations can monitor signal strength quickly. Experimental results show that a handoff decision can be made within a second, even under slow fading (such as walking speed), which agrees with the theoretical calculation very well. It is shown that the whole handoff procedure works reliably under a typical microcell propagation condition.<>
{"title":"Experimental digital cellular system for microcellular handoff","authors":"T. Kanai, M. Taketsugu, S. Kondo","doi":"10.1109/VETEC.1990.110316","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110316","url":null,"abstract":"An experimental digital cellular system composed of a private branch exchange (PBX)-based MSC (mobile switching center), three base stations, two mobile stations, and a radio channel simulator, is developed. The system uses a mobile originated handoff process; i.e. a mobile station requests a handoff to the MSC based on signal strength from surrounding base stations. All control channels are multiplexed on the same carrier so that mobile stations can monitor signal strength quickly. Experimental results show that a handoff decision can be made within a second, even under slow fading (such as walking speed), which agrees with the theoretical calculation very well. It is shown that the whole handoff procedure works reliably under a typical microcell propagation condition.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"67 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":"133649226","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.1990.110331
W.R. Mande
In the future pan-European cellular mobile telephone system of the 'Groupe Speciale Mobile (GSM)' of CEPT, the decision whether a handover shall happen can be based on a set of variables whose values are measured in the system. Some performance measures for handover algorithms are reported, and a simulation tool for the evaluation of a proposed GSM handover algorithm is described. Some results of the evaluation are included. Special attention is given to the time over which the sampled values are averaged. The evaluation is based on a model of a cellular network, where the radio propagation characteristics are assumed to follow a lognormal law with Rayleigh fading. For given routes of mobiles, measurements of the received signal level are obtained by simulation and fed to the handover algorithm.<>
{"title":"Evaluation of a proposed handover algorithm for the GSM cellular system","authors":"W.R. Mande","doi":"10.1109/VETEC.1990.110331","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110331","url":null,"abstract":"In the future pan-European cellular mobile telephone system of the 'Groupe Speciale Mobile (GSM)' of CEPT, the decision whether a handover shall happen can be based on a set of variables whose values are measured in the system. Some performance measures for handover algorithms are reported, and a simulation tool for the evaluation of a proposed GSM handover algorithm is described. Some results of the evaluation are included. Special attention is given to the time over which the sampled values are averaged. The evaluation is based on a model of a cellular network, where the radio propagation characteristics are assumed to follow a lognormal law with Rayleigh fading. For given routes of mobiles, measurements of the received signal level are obtained by simulation and fed to the handover algorithm.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"7 11","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114031552","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.1990.110362
P. Mogensen, B.L. Andersen, B. Madsen, J. Andersen
Measurements of complex impulse responses and transmission of pan-European mobile telephone system GSM timeslots have been carried out in different environments. The short-term variations of the mobile channel have been simulated on computer for comparison. Power, time and phase gradients put demands on the receiver. The variations of these parameters are discussed in theoretical, numerical, and experimental terms. The experimentally obtained values of power gradients are on the order 10 dB between two frames at the 1% level, while the variation from one timeslot to the next is on the order 3 dB at normal speeds of about 50 km/h. Theoretically obtained values show considerably higher variations. The distributions of time-jitter as a function of different environments are also given.<>
{"title":"Short-term variations of the mobile channel and the GSM signal","authors":"P. Mogensen, B.L. Andersen, B. Madsen, J. Andersen","doi":"10.1109/VETEC.1990.110362","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110362","url":null,"abstract":"Measurements of complex impulse responses and transmission of pan-European mobile telephone system GSM timeslots have been carried out in different environments. The short-term variations of the mobile channel have been simulated on computer for comparison. Power, time and phase gradients put demands on the receiver. The variations of these parameters are discussed in theoretical, numerical, and experimental terms. The experimentally obtained values of power gradients are on the order 10 dB between two frames at the 1% level, while the variation from one timeslot to the next is on the order 3 dB at normal speeds of about 50 km/h. Theoretically obtained values show considerably higher variations. The distributions of time-jitter as a function of different environments are also given.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"75 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":"116260081","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.1990.110348
J. Mccartin, T. Ha
An analysis of the throughput for two variable-packet ALOHA network models is presented. Variable-packet ALOHA does not require (1) padded bits to fill up a packet to its specified length (which may significantly reduce the throughput of fixed-packet ALOHA), or (2) bit stuffing and destuffing logics (which increase equipment cost in fixed-packet ALOHA). The first model uses random two power levels to induce receiver capture. The second model considers the near/far effect between users and the base station in a local or mobile radio networkl. Analytical results that indicate a significant increase in throughput for both models are presented.<>
{"title":"Variable packet ALOHA networks","authors":"J. Mccartin, T. Ha","doi":"10.1109/VETEC.1990.110348","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110348","url":null,"abstract":"An analysis of the throughput for two variable-packet ALOHA network models is presented. Variable-packet ALOHA does not require (1) padded bits to fill up a packet to its specified length (which may significantly reduce the throughput of fixed-packet ALOHA), or (2) bit stuffing and destuffing logics (which increase equipment cost in fixed-packet ALOHA). The first model uses random two power levels to induce receiver capture. The second model considers the near/far effect between users and the base station in a local or mobile radio networkl. Analytical results that indicate a significant increase in throughput for both models are presented.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"33 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":"124988726","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.1990.110398
G. Falciasecca, M. Frullone, G. Riva, A. M. Serra
The effect of unpredictable traffic oscillations (due to traffic jams or accidents for example) occurring in urban areas with heavy road traffic and resulting in unacceptable performances of mobile radio systems are studied. The main goal is to determine whether an improvement in counteracting traffic bursts can be accomplished by means of dynamic channel allocation (DCA), with respect to fixed schemes. The control and management procedures used in the analysis do not represent a proposal for the architecture of the final system. They are very simple, and should be intended only as tools for illustrating the capabilities of DCA strategies. A description of a methodology suitable for evaluating system performances is given. The performance of fixed and dynamic schemes, with uniform spatial traffic distribution by means of a computer simulation program, are compared. A cellular layout based on a hexagonal grid where cell radius is equal to one kilometer is considered.<>
{"title":"On the impact of traffic burst on performances of high capacity cellular systems","authors":"G. Falciasecca, M. Frullone, G. Riva, A. M. Serra","doi":"10.1109/VETEC.1990.110398","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110398","url":null,"abstract":"The effect of unpredictable traffic oscillations (due to traffic jams or accidents for example) occurring in urban areas with heavy road traffic and resulting in unacceptable performances of mobile radio systems are studied. The main goal is to determine whether an improvement in counteracting traffic bursts can be accomplished by means of dynamic channel allocation (DCA), with respect to fixed schemes. The control and management procedures used in the analysis do not represent a proposal for the architecture of the final system. They are very simple, and should be intended only as tools for illustrating the capabilities of DCA strategies. A description of a methodology suitable for evaluating system performances is given. The performance of fixed and dynamic schemes, with uniform spatial traffic distribution by means of a computer simulation program, are compared. A cellular layout based on a hexagonal grid where cell radius is equal to one kilometer is considered.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"19 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":"128142098","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.1990.110356
H. Leib, S. Pasupathy
Noncoherent demodulation of phase shift keying (PSK) over a multisymbol observation interval is considered. It is shown that by performing noncoherent demodulation over an increased observation interval, the performance approaches that of coherent PSK. This block demodulation technique of PSK is a natural generalization of differentially coherent detection, and yields improved signal-to-noise ratio (SNR) performance. Some structural properties of this demodulation technique are explored, and its performance is analyzed by using the union-bound.<>
{"title":"Noncoherent block demodulation of PSK","authors":"H. Leib, S. Pasupathy","doi":"10.1109/VETEC.1990.110356","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110356","url":null,"abstract":"Noncoherent demodulation of phase shift keying (PSK) over a multisymbol observation interval is considered. It is shown that by performing noncoherent demodulation over an increased observation interval, the performance approaches that of coherent PSK. This block demodulation technique of PSK is a natural generalization of differentially coherent detection, and yields improved signal-to-noise ratio (SNR) performance. Some structural properties of this demodulation technique are explored, and its performance is analyzed by using the union-bound.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"42 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":"127989929","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.1990.110392
S. Mockford, A. Turkmani, J. D. Parsons
Analysis of mobile radio propagation results from surveys made in rural areas of England have shown that over different distances, the local mean of the signal envelope is well described by a lognormal distribution. This analysis has provided a knowledge of the standard deviation of the lognormal distribution, sigma /sub L/, as a function of the size of area under consideration. It has also shown categorically that sigma /sub L/ is independent of path length. Large amounts of data were collected along several survey routes, so that the parameters of a local mean fading simulator could be determined. The power spectral density of the local mean signal measured along rural routes is estimated. The relative spectral density of the local mean signal variations is found to be always less than -10 dB for frequencies greater than f/sub D//360.<>
{"title":"Local mean signal variability in rural areas at 900 MHz","authors":"S. Mockford, A. Turkmani, J. D. Parsons","doi":"10.1109/VETEC.1990.110392","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110392","url":null,"abstract":"Analysis of mobile radio propagation results from surveys made in rural areas of England have shown that over different distances, the local mean of the signal envelope is well described by a lognormal distribution. This analysis has provided a knowledge of the standard deviation of the lognormal distribution, sigma /sub L/, as a function of the size of area under consideration. It has also shown categorically that sigma /sub L/ is independent of path length. Large amounts of data were collected along several survey routes, so that the parameters of a local mean fading simulator could be determined. The power spectral density of the local mean signal measured along rural routes is estimated. The relative spectral density of the local mean signal variations is found to be always less than -10 dB for frequencies greater than f/sub D//360.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"s3-50 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":"130238653","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.1990.110365
S. Sampei, T. Sunaga
A novel type of space diversity with maximal ratio combining for multilevel quadrature amplitude modulation (QAM) in land mobile communications to improve transmission performance is proposed. In order to realize maximal ratio combining space diversity for QAM, a novel type of diversity combining method using a pilot symbol insertion type fading estimator is applied. The proposed diversity combining is carried out at the baseband using digital signal processing, simplifying the diversity receiver hardware. Computer simulation and laboratory experiments confirm that the multilevel QAM using the proposed method is effective for improving the transmission performance of land mobile communications.<>
{"title":"Performance of multi-level QAM with maximal ratio combining space diversity for land mobile radio communications","authors":"S. Sampei, T. Sunaga","doi":"10.1109/VETEC.1990.110365","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110365","url":null,"abstract":"A novel type of space diversity with maximal ratio combining for multilevel quadrature amplitude modulation (QAM) in land mobile communications to improve transmission performance is proposed. In order to realize maximal ratio combining space diversity for QAM, a novel type of diversity combining method using a pilot symbol insertion type fading estimator is applied. The proposed diversity combining is carried out at the baseband using digital signal processing, simplifying the diversity receiver hardware. Computer simulation and laboratory experiments confirm that the multilevel QAM using the proposed method is effective for improving the transmission performance of land mobile communications.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"23 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":"124691765","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.1990.110338
R. W. Nettleton
A novel family of techniques for assigning channels to calls in a cellular mobile telephone system based on real-time measurements of signal strength is introduced. A discussion of the behavior of the system using self-organizing techniques is presented. Results are presented for traffic distribution per channel, traffic distribution per cell site, mean time between handoffs, and mean signal-to-interference ratio. In each case, it is shown that the system behavior is progressive and degrades gracefully with increasing traffic; there is, for example, no threshold behavior in signal-to-interference ratio. This suggests that the concept can be introduced in stages as the traffic demand increases, without abrupt changes in system behavior.<>
{"title":"Traffic statistics in a self-organizing cellular telephone system","authors":"R. W. Nettleton","doi":"10.1109/VETEC.1990.110338","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110338","url":null,"abstract":"A novel family of techniques for assigning channels to calls in a cellular mobile telephone system based on real-time measurements of signal strength is introduced. A discussion of the behavior of the system using self-organizing techniques is presented. Results are presented for traffic distribution per channel, traffic distribution per cell site, mean time between handoffs, and mean signal-to-interference ratio. In each case, it is shown that the system behavior is progressive and degrades gracefully with increasing traffic; there is, for example, no threshold behavior in signal-to-interference ratio. This suggests that the concept can be introduced in stages as the traffic demand increases, without abrupt changes in system behavior.<<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":"128457857","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.1990.110329
G. Atkin, R.A. Khalona
Signal sets are considered which give rise to multitone M-ary frequency shift keying (MT-MFSK) modulation, which represents a bandwidth efficient alternative to optimum performance modulation schemes for the AWGN channel (simplex signaling for coherent detection and orthogonal signaling for noncoherent detection). The channel is examined in the power-limited region, and it is shown that MT-MFSK modulation exhibits optimum asymptotic performance with bandwidth efficiency gains of an order of magnitude over the orthogonal MFSK modulation technique for sets of finite size. MT-MFSK is viewed as a class of signal sets derived from combinatorial designs. The main properties and structure of such sets are presented and exploited to derive tight upper bounds for the error probability.<>
{"title":"Bandwidth efficient signal sets with partitioned equicorrelated properties for the AWGN channel","authors":"G. Atkin, R.A. Khalona","doi":"10.1109/VETEC.1990.110329","DOIUrl":"https://doi.org/10.1109/VETEC.1990.110329","url":null,"abstract":"Signal sets are considered which give rise to multitone M-ary frequency shift keying (MT-MFSK) modulation, which represents a bandwidth efficient alternative to optimum performance modulation schemes for the AWGN channel (simplex signaling for coherent detection and orthogonal signaling for noncoherent detection). The channel is examined in the power-limited region, and it is shown that MT-MFSK modulation exhibits optimum asymptotic performance with bandwidth efficiency gains of an order of magnitude over the orthogonal MFSK modulation technique for sets of finite size. MT-MFSK is viewed as a class of signal sets derived from combinatorial designs. The main properties and structure of such sets are presented and exploited to derive tight upper bounds for the error probability.<<ETX>>","PeriodicalId":366352,"journal":{"name":"40th IEEE Conference on Vehicular Technology","volume":"23 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":"125569939","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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