Pub Date : 1997-09-01DOI: 10.1109/PIMRC.1997.630968
J. Brecht, L. Hanzo, M. D. Buono
Multi-frame packet reservation multiple access or MF-PRMA is proposed for supporting multi-rate, multi-media users in high-rate systems employing time-division multi-frames. PRMA and MF-PRMA are compared for a variety of traffic scenarios using optimised system parameters.
{"title":"Multi-frame packet reservation multiple access for variable-rate multimedia users","authors":"J. Brecht, L. Hanzo, M. D. Buono","doi":"10.1109/PIMRC.1997.630968","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.630968","url":null,"abstract":"Multi-frame packet reservation multiple access or MF-PRMA is proposed for supporting multi-rate, multi-media users in high-rate systems employing time-division multi-frames. PRMA and MF-PRMA are compared for a variety of traffic scenarios using optimised system parameters.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121042948","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 : 1997-09-01DOI: 10.1109/PIMRC.1997.631109
M. Williamson, G. Athanasiadou, A. Nix
This paper investigates the nature of the indoor radio channel at 60 GHz, with regard to its use for future high bit-rate broadband wireless networks. It is proposed that, for operation in the millimetre-wave indoor channel, directional antennas can be used to mitigate multipath effects, thus reducing the need for complex equalisation or multi-carrier techniques. An image based, ray-tracing prediction model is used to study the channel characteristics and to analyse the variation in received power, RMS delay spread and k-factor within a typical operating environment. The performances of different antenna combinations are investigated and narrowbeam, suitably aligned antennas are shown to reduce received delay spread for both LOS and non-LOS locations. The effects of non-optimal antenna alignment are observed, and system outage is determined for certain system design criteria. The results suggest that it will feasible to combat multipath effects using switched-beam directional antennas.
{"title":"Investigating the effects of antenna directivity on wireless indoor communication at 60 GHz","authors":"M. Williamson, G. Athanasiadou, A. Nix","doi":"10.1109/PIMRC.1997.631109","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.631109","url":null,"abstract":"This paper investigates the nature of the indoor radio channel at 60 GHz, with regard to its use for future high bit-rate broadband wireless networks. It is proposed that, for operation in the millimetre-wave indoor channel, directional antennas can be used to mitigate multipath effects, thus reducing the need for complex equalisation or multi-carrier techniques. An image based, ray-tracing prediction model is used to study the channel characteristics and to analyse the variation in received power, RMS delay spread and k-factor within a typical operating environment. The performances of different antenna combinations are investigated and narrowbeam, suitably aligned antennas are shown to reduce received delay spread for both LOS and non-LOS locations. The effects of non-optimal antenna alignment are observed, and system outage is determined for certain system design criteria. The results suggest that it will feasible to combat multipath effects using switched-beam directional antennas.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114076130","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 : 1997-09-01DOI: 10.1109/PIMRC.1997.630898
W. Hollemans, R. Prasad, A. Kegel
The performance of cellular digital mobile radio systems is investigated using quadrature amplitude modulation (4-QAM) and differential phase shift keying (DPSK) in a frequency nonselective Rayleigh fading environment with lognormal shadowing, including the effects of (white) Gaussian noise, narrow-band impulsive noise/interference (Middleton's Class A model), and cochannel interference. The performance is analyzed in terms of probability of bit error. The UHF groundwave propagation law is introduced by considering the local mean power to be inversely proportional to the fourth power of propagation distance. To investigate the improvement in performance the influence of selection diversity and maximal ratio combining on the bit error probability is analyzed. It has been found that shadowing significantly affects the bit error performance. Application of selection diversity or maximal ratio combining results in important improvement of system performance. Selection diversity gives better results than maximal ratio combining for low signal-to-noise ratios. Results of our analysis show maximal ratio combining is not that sensitive to unequal branch signal-to-noise-plus-interference ratio.
{"title":"Performance analysis of cellular digital mobile radio systems including diversity techniques","authors":"W. Hollemans, R. Prasad, A. Kegel","doi":"10.1109/PIMRC.1997.630898","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.630898","url":null,"abstract":"The performance of cellular digital mobile radio systems is investigated using quadrature amplitude modulation (4-QAM) and differential phase shift keying (DPSK) in a frequency nonselective Rayleigh fading environment with lognormal shadowing, including the effects of (white) Gaussian noise, narrow-band impulsive noise/interference (Middleton's Class A model), and cochannel interference. The performance is analyzed in terms of probability of bit error. The UHF groundwave propagation law is introduced by considering the local mean power to be inversely proportional to the fourth power of propagation distance. To investigate the improvement in performance the influence of selection diversity and maximal ratio combining on the bit error probability is analyzed. It has been found that shadowing significantly affects the bit error performance. Application of selection diversity or maximal ratio combining results in important improvement of system performance. Selection diversity gives better results than maximal ratio combining for low signal-to-noise ratios. Results of our analysis show maximal ratio combining is not that sensitive to unequal branch signal-to-noise-plus-interference ratio.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122501189","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 : 1997-09-01DOI: 10.1109/PIMRC.1997.626995
C. Tellambura, I. Johnson, Y. Guo, S. Barton
To reduce the effects of intersymbol interference resulting from the dispersive nature of the indoor radio channel most HIPERLAN receivers will incorporate an adaptive equaliser. The computational complexity of several equaliser algorithms is estimated. The effect of frequency offset between the transmitter and receiver on the performance of such an equaliser is investigated. By employing a decision feedback equaliser incorporating a second order phase locked loop, the effect of both the intersymbol interference and frequency offset can be significantly reduced. Using such a technique, the packet error ratio (PER) of a HIPERLAN radio link in a multipath channel is found by simulation.
{"title":"Equalisation and frequency offset correction for HIPERLAN","authors":"C. Tellambura, I. Johnson, Y. Guo, S. Barton","doi":"10.1109/PIMRC.1997.626995","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.626995","url":null,"abstract":"To reduce the effects of intersymbol interference resulting from the dispersive nature of the indoor radio channel most HIPERLAN receivers will incorporate an adaptive equaliser. The computational complexity of several equaliser algorithms is estimated. The effect of frequency offset between the transmitter and receiver on the performance of such an equaliser is investigated. By employing a decision feedback equaliser incorporating a second order phase locked loop, the effect of both the intersymbol interference and frequency offset can be significantly reduced. Using such a technique, the packet error ratio (PER) of a HIPERLAN radio link in a multipath channel is found by simulation.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122619776","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 : 1997-09-01DOI: 10.1109/PIMRC.1997.624399
S. Grujev, R. Prasad
The paper presents the performance analysis in terms of outage probability of a cellular hybrid DS/SFH CDMA system for the analytical channel model. The mobile-to-base link is modelled as a Rayleigh fading channel with all users experiencing independent fading. The standard receiver for CDMA systems is susceptible to the near-far effect problem. Power control techniques attempt to overcome near-far effect by varying transmitted power levels to ensure that all signals are received with equal power levels. We evaluated the performance for given a bit rate in a situation with and without power control and selection diversity. Since the power control algorithms cannot perfectly compensate for power fluctuations in a mobile communications channel, the performance of the system is reduced for a given BER. This paper examines the effect of imperfect power control on the number of users by extending analytical techniques that account for multiple access and adjacent cell interference.
{"title":"Outage probability of a cellular hybrid DS/SFH CDMA system","authors":"S. Grujev, R. Prasad","doi":"10.1109/PIMRC.1997.624399","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.624399","url":null,"abstract":"The paper presents the performance analysis in terms of outage probability of a cellular hybrid DS/SFH CDMA system for the analytical channel model. The mobile-to-base link is modelled as a Rayleigh fading channel with all users experiencing independent fading. The standard receiver for CDMA systems is susceptible to the near-far effect problem. Power control techniques attempt to overcome near-far effect by varying transmitted power levels to ensure that all signals are received with equal power levels. We evaluated the performance for given a bit rate in a situation with and without power control and selection diversity. Since the power control algorithms cannot perfectly compensate for power fluctuations in a mobile communications channel, the performance of the system is reduced for a given BER. This paper examines the effect of imperfect power control on the number of users by extending analytical techniques that account for multiple access and adjacent cell interference.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129568196","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 : 1997-09-01DOI: 10.1109/PIMRC.1997.631179
M. Reed, P. Alexander, J. Asenstorfer, C. Schlegel
This paper discusses a code-division multiple access (CDMA) iterative multi-user receiver with forward error control (FEC) decoding. The maximum a-posteriori probability (MAP) criteria is used to derive the receiver. The decoding is done using a turbo-code decoder with modifications which are discussed. Iterations of the system are used to attain large performance improvements over conventional systems.
{"title":"Near single user performance using iterative multi-user detection for CDMA with turbo-code decoders","authors":"M. Reed, P. Alexander, J. Asenstorfer, C. Schlegel","doi":"10.1109/PIMRC.1997.631179","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.631179","url":null,"abstract":"This paper discusses a code-division multiple access (CDMA) iterative multi-user receiver with forward error control (FEC) decoding. The maximum a-posteriori probability (MAP) criteria is used to derive the receiver. The decoding is done using a turbo-code decoder with modifications which are discussed. Iterations of the system are used to attain large performance improvements over conventional systems.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128055769","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 : 1997-09-01DOI: 10.1109/PIMRC.1997.627068
M-Reza Koohrangpour, A. Svensson
Direct-sequence code-division multiple access (DS-CDMA) is a popular wireless technology. In DS-CDMA communications, all of the users' signals overlap in time and frequency and cause mutual interference. In this paper a novel multi-user decoding scheme for coded synchronous DS-CDMA is proposed. The decoder performs joint successive interference cancellation (SIC) and Viterbi decoding (VD) in each step of the interference cancellation. In a conventional SIC scheme, SIC is performed first, followed by VD that uses the outputs of the last stage of the SIC scheme for metric calculation. Simulated bit error probability for the proposed scheme is presented and compared with bit error probability of a conventional scheme. A capacity increase of at least 4 compared to SIC followed by VD is reported in one example.
直接序列码分多址（DS-CDMA）是一种流行的无线技术。在 DS-CDMA 通信中，所有用户的信号在时间和频率上都会重叠，从而造成相互干扰。本文针对编码同步 DS-CDMA 提出了一种新型多用户解码方案。解码器在干扰消除的每一步都执行联合连续干扰消除（SIC）和维特比解码（VD）。在传统的 SIC 方案中，首先执行 SIC，然后执行 VD，VD 使用 SIC 方案最后阶段的输出进行度量计算。演示了拟议方案的模拟误码率，并与传统方案的误码率进行了比较。在一个实例中，与先 SIC 后 VD 的方案相比，容量至少增加了 4 倍。
{"title":"Joint interference cancellation and Viterbi decoding in DS-CDMA","authors":"M-Reza Koohrangpour, A. Svensson","doi":"10.1109/PIMRC.1997.627068","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.627068","url":null,"abstract":"Direct-sequence code-division multiple access (DS-CDMA) is a popular wireless technology. In DS-CDMA communications, all of the users' signals overlap in time and frequency and cause mutual interference. In this paper a novel multi-user decoding scheme for coded synchronous DS-CDMA is proposed. The decoder performs joint successive interference cancellation (SIC) and Viterbi decoding (VD) in each step of the interference cancellation. In a conventional SIC scheme, SIC is performed first, followed by VD that uses the outputs of the last stage of the SIC scheme for metric calculation. Simulated bit error probability for the proposed scheme is presented and compared with bit error probability of a conventional scheme. A capacity increase of at least 4 compared to SIC followed by VD is reported in one example.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128479090","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 : 1997-09-01DOI: 10.1109/PIMRC.1997.627059
J. Kivinen, P. Vainikainen
This paper describes the problems caused by the phase noise in the development of micro- and millimeterwave range crosscorrelation type wideband channel sounders. The procedure to estimate the phase noise and its effect on the dynamic range of the impulse response measurement is given. It can be seen that the effect of the phase noise becomes more significant as the measurement frequency increases. With typical components a dynamic range of 35 dB was estimated at 60 GHz.
{"title":"Phase noise in a direct sequence based channel sounder","authors":"J. Kivinen, P. Vainikainen","doi":"10.1109/PIMRC.1997.627059","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.627059","url":null,"abstract":"This paper describes the problems caused by the phase noise in the development of micro- and millimeterwave range crosscorrelation type wideband channel sounders. The procedure to estimate the phase noise and its effect on the dynamic range of the impulse response measurement is given. It can be seen that the effect of the phase noise becomes more significant as the measurement frequency increases. With typical components a dynamic range of 35 dB was estimated at 60 GHz.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121623705","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 : 1997-09-01DOI: 10.1109/PIMRC.1997.631154
F. Babich, F. Vatta
The bit-stream generated by most source coding algorithms, for voice, audio and images, usually consists of bits of different significance and error sensitivity. By exploiting this property, in the design of a wireless communication system, it is possible to obtain significant advantages. First, the network capacity can be increased, with a smoother quality degradation under heavy traffic or severe interference conditions. Secondly, the application of source sensitivity matched FEC (forward error correction) protection schemes, leads to a higher robustness of source bits to channel impairments. We evaluate the usefulness of prioritized, variable-rate speech encoding schemes, for handling congestion over packet switching systems. The system performance is shown to be sensitive to the fraction of information placed in each priority and to the number of priorities. The applicability of source-sensitivity matched error protection schemes, for variable-rate speech transmission on a radio channel, is also investigated.
{"title":"Source-matched channel coding and networking techniques for mobile communications","authors":"F. Babich, F. Vatta","doi":"10.1109/PIMRC.1997.631154","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.631154","url":null,"abstract":"The bit-stream generated by most source coding algorithms, for voice, audio and images, usually consists of bits of different significance and error sensitivity. By exploiting this property, in the design of a wireless communication system, it is possible to obtain significant advantages. First, the network capacity can be increased, with a smoother quality degradation under heavy traffic or severe interference conditions. Secondly, the application of source sensitivity matched FEC (forward error correction) protection schemes, leads to a higher robustness of source bits to channel impairments. We evaluate the usefulness of prioritized, variable-rate speech encoding schemes, for handling congestion over packet switching systems. The system performance is shown to be sensitive to the fraction of information placed in each priority and to the number of priorities. The applicability of source-sensitivity matched error protection schemes, for variable-rate speech transmission on a radio channel, is also investigated.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"66 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120842345","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 : 1997-09-01DOI: 10.1109/PIMRC.1997.624356
K. Pehkonen, H. Holma, I. Keskitalo, E. Nikula, T. Westman
Universal Mobile Telecommunications System (UMTS) has a target maximum user bit rate of 2 Mbit/s. We present a performance comparison between four TDMA schemes and one CDMA scheme that all can provide the required user data rate. Evaluation considers link level performance, noise limited uplink range and cellular capacity. Three different environments, indoor large room, street micro cell and urban macro cell, have been used. Results show that when sophisticated methods are utilized schemes based on both TDMA and CDMA access methods can provide very similar performance for implementing UMTS high bit rate services when many different environments are considered.
{"title":"A performance analysis of TDMA and CDMA based air interface solutions for UMTS high bit rate services","authors":"K. Pehkonen, H. Holma, I. Keskitalo, E. Nikula, T. Westman","doi":"10.1109/PIMRC.1997.624356","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.624356","url":null,"abstract":"Universal Mobile Telecommunications System (UMTS) has a target maximum user bit rate of 2 Mbit/s. We present a performance comparison between four TDMA schemes and one CDMA scheme that all can provide the required user data rate. Evaluation considers link level performance, noise limited uplink range and cellular capacity. Three different environments, indoor large room, street micro cell and urban macro cell, have been used. Results show that when sophisticated methods are utilized schemes based on both TDMA and CDMA access methods can provide very similar performance for implementing UMTS high bit rate services when many different environments are considered.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"5 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121349479","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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