Pub Date : 1997-09-01DOI: 10.1109/PIMRC.1997.631059
P. Hafezi, D. Wedge, M. Beach, M. Lawton
This paper presents the results of an investigation into the wideband propagation characteristics of four different indoor operational environments within the 5.2 GHz band using a swept time-delay cross-correlator (STDCC) channel sounder. For each environment the cumulative distribution of delay spread for both omni-directional and a 20 dB horn antenna are presented. It is shown that a suitably aligned narrowbeam antenna makes possible to achieve delay spread reduction through spatial filtering. The effects of moving people and different room transmission situations are also presented.
{"title":"Propagation measurements at 5.2 GHz in commercial and domestic environments","authors":"P. Hafezi, D. Wedge, M. Beach, M. Lawton","doi":"10.1109/PIMRC.1997.631059","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.631059","url":null,"abstract":"This paper presents the results of an investigation into the wideband propagation characteristics of four different indoor operational environments within the 5.2 GHz band using a swept time-delay cross-correlator (STDCC) channel sounder. For each environment the cumulative distribution of delay spread for both omni-directional and a 20 dB horn antenna are presented. It is shown that a suitably aligned narrowbeam antenna makes possible to achieve delay spread reduction through spatial filtering. The effects of moving people and different room transmission situations are also presented.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"28 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":"117304915","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.1997.630968
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.1997.630967
R. Verdone
Packet radio systems with random multiple access where the geometry of the scenario determines the presence of a maximum of two simultaneous transmitters, are analysed. Packet capture probability is evaluated in order to investigate the possible improvements of the random transmission power strategy first proposed by Lee (1987). Propagation is characterised by a path-loss exponent. The capture effect is taken into account by means of a threshold model. Averaging over interfering distance is accomplished. After an analytical development, the packet capture probability is found to be determinable by means of closed-form expressions. It is shown that the random transmission power strategy improves system performance in certain conditions. Some examples of application of this technique are given.
{"title":"On the performance improvement of packet radio systems with one single interferer due to random transmission power strategy","authors":"R. Verdone","doi":"10.1109/PIMRC.1997.630967","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.630967","url":null,"abstract":"Packet radio systems with random multiple access where the geometry of the scenario determines the presence of a maximum of two simultaneous transmitters, are analysed. Packet capture probability is evaluated in order to investigate the possible improvements of the random transmission power strategy first proposed by Lee (1987). Propagation is characterised by a path-loss exponent. The capture effect is taken into account by means of a threshold model. Averaging over interfering distance is accomplished. After an analytical development, the packet capture probability is found to be determinable by means of closed-form expressions. It is shown that the random transmission power strategy improves system performance in certain conditions. Some examples of application of this technique are given.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"35 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":"116672505","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}
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.1997.627052
M. Lamarca, G. Vázquez
A blind algorithm for channel distortion compensation is presented which can be employed in spatial or temporal diversity receivers. The proposed technique can be used in frequency selective and frequency flat fading mobile channels, using burst transmission schemes in the first case and OFDM modulation in the second one. The algorithm is base on a deterministic criteria and is suited for estimation when short sets of data are available.
{"title":"Diversity techniques for blind channel equalization in mobile communications","authors":"M. Lamarca, G. Vázquez","doi":"10.1109/PIMRC.1997.627052","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.627052","url":null,"abstract":"A blind algorithm for channel distortion compensation is presented which can be employed in spatial or temporal diversity receivers. The proposed technique can be used in frequency selective and frequency flat fading mobile channels, using burst transmission schemes in the first case and OFDM modulation in the second one. The algorithm is base on a deterministic criteria and is suited for estimation when short sets of data are available.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"12 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":"124934547","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.1997.627068
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.1997.624376
H. Matsutani, Y. Sanada, M. Nakagawa
A new intracell orthogonalization technique for a code division multiple access (CDMA) wireless local communication system is posed. On the forward link of the system, it is necessary to achieve high bit rate transmission and to reduce the complexity of the receiving terminal. To meet these two requirements, cyclically shifted spreading sequences are utilized. However, it is necessary to orthogonalize the multiple signals since these sequences are cross-correlated. One way of achieving orthogonalization is pre-decorrelation. However, the orthogonality does not clearly appear in a multipath fading channel because of the interchip interference caused by multipath. Therefore in this paper, pre-decorrelation is combined with multicarrier modulation. The results obtained through computer simulation show that the proposed technique can achieve orthogonality in a multipath fading channel. Also the proposed technique makes efficient forward link power control possible, and reduces intercell interference.
{"title":"A forward link intracell orthogonalization technique using multicarrier pre-decorrelation for CDMA wireless local communication system","authors":"H. Matsutani, Y. Sanada, M. Nakagawa","doi":"10.1109/PIMRC.1997.624376","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.624376","url":null,"abstract":"A new intracell orthogonalization technique for a code division multiple access (CDMA) wireless local communication system is posed. On the forward link of the system, it is necessary to achieve high bit rate transmission and to reduce the complexity of the receiving terminal. To meet these two requirements, cyclically shifted spreading sequences are utilized. However, it is necessary to orthogonalize the multiple signals since these sequences are cross-correlated. One way of achieving orthogonalization is pre-decorrelation. However, the orthogonality does not clearly appear in a multipath fading channel because of the interchip interference caused by multipath. Therefore in this paper, pre-decorrelation is combined with multicarrier modulation. The results obtained through computer simulation show that the proposed technique can achieve orthogonality in a multipath fading channel. Also the proposed technique makes efficient forward link power control possible, and reduces intercell interference.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"50 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":"128385339","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}
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