Pub Date : 1996-10-15DOI: 10.1109/PIMRC.1996.568471
J. Mar, Hung-Yi Chen
An effect of multipath on the performance of cellular code division multiple access (CDMA) is investigated. The bit error rate (BER) for both the forward link and reverse link over Rayleigh frequency-selective fading channels are derived. The coherent BPSK modulation with asynchronous direct-sequence (DS) spreading is assumed. The analysis results show the performance degradation of cellular CDMA system as the number of simultaneous users increase. The impact of imperfect power control on the performance of the cellular CDMA system is also investigated.
{"title":"Performance evaluation of a cellular CDMA system over frequency-selective fading channels","authors":"J. Mar, Hung-Yi Chen","doi":"10.1109/PIMRC.1996.568471","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.568471","url":null,"abstract":"An effect of multipath on the performance of cellular code division multiple access (CDMA) is investigated. The bit error rate (BER) for both the forward link and reverse link over Rayleigh frequency-selective fading channels are derived. The coherent BPSK modulation with asynchronous direct-sequence (DS) spreading is assumed. The analysis results show the performance degradation of cellular CDMA system as the number of simultaneous users increase. The impact of imperfect power control on the performance of the cellular CDMA system is also investigated.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122814654","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567460
M. Jin, K. Kwak
In this paper, we propose some schemes of efficient multiple access for multiuser detection in spread spectrum communications. The first scheme is based on the relationship between Walsh code and PN code, and the second and third scheme are based on new scheme called code hopping CDMA (CH-CDMA), but with different signal sets.
{"title":"A new scheme for multiuser detection in DS-CDMA system","authors":"M. Jin, K. Kwak","doi":"10.1109/PIMRC.1996.567460","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567460","url":null,"abstract":"In this paper, we propose some schemes of efficient multiple access for multiuser detection in spread spectrum communications. The first scheme is based on the relationship between Walsh code and PN code, and the second and third scheme are based on new scheme called code hopping CDMA (CH-CDMA), but with different signal sets.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125165232","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.568472
O. Sallent, R. Agustí
This paper presents a novel adaptive DS-CDMA slotted-ALOHA packet random access scheme with transmitter-based spreading codes for mobiles. It is aimed at improving the throughput and message delay delivery when traffic load values below the saturation point of the conventional DS-CDMA slotted-ALOHA system are sensed in the channel. For this purpose a mobile assisted algorithm is envisaged to control the change of the transmission rate according to the traffic load. This algorithm revealed that the optimum behavior, obtained using a Markov chain model, may be almost reached at a low complexity cost. Moreover, priorities between mobiles could be easily established. Finally, a traffic model based on a realistic statistical length distribution of the messages illustrates how the delay delivery can be greatly reduced.
{"title":"A mobile controlled algorithm for improving the throughput in a S-ALOHA DS-CDMA system","authors":"O. Sallent, R. Agustí","doi":"10.1109/PIMRC.1996.568472","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.568472","url":null,"abstract":"This paper presents a novel adaptive DS-CDMA slotted-ALOHA packet random access scheme with transmitter-based spreading codes for mobiles. It is aimed at improving the throughput and message delay delivery when traffic load values below the saturation point of the conventional DS-CDMA slotted-ALOHA system are sensed in the channel. For this purpose a mobile assisted algorithm is envisaged to control the change of the transmission rate according to the traffic load. This algorithm revealed that the optimum behavior, obtained using a Markov chain model, may be almost reached at a low complexity cost. Moreover, priorities between mobiles could be easily established. Finally, a traffic model based on a realistic statistical length distribution of the messages illustrates how the delay delivery can be greatly reduced.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125194683","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567400
WuSeong Lee, D.J.Y. Lee
A model constituting microcell prediction under real terrain, considering the effects of terrain contour changes on urban microcell radio propagation is proposed. Various comparisons were done to show that the model is appropriate under line of sight, obstruction due to terrain contours i.e.: under shadow conditions also when blocked by buildings. Wide scale analysis on the San Francisco, Tokyo, Amsterdam and Rome terrain proved the model calculation for diffraction loss and effective antenna gains encountered in the path of the mobile fairly accurate.
{"title":"Microcell prediction enhancement for terrain","authors":"WuSeong Lee, D.J.Y. Lee","doi":"10.1109/PIMRC.1996.567400","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567400","url":null,"abstract":"A model constituting microcell prediction under real terrain, considering the effects of terrain contour changes on urban microcell radio propagation is proposed. Various comparisons were done to show that the model is appropriate under line of sight, obstruction due to terrain contours i.e.: under shadow conditions also when blocked by buildings. Wide scale analysis on the San Francisco, Tokyo, Amsterdam and Rome terrain proved the model calculation for diffraction loss and effective antenna gains encountered in the path of the mobile fairly accurate.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125662077","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567535
S. Tasaka, H. Imura
This paper describes an experiment of a temporal resolution control scheme of stored video traffic in a wireless LAN. The scheme switches the resolution between two levels according to the network load. We propose a simple method of detecting network congestion which uses only local information. We have implemented the scheme on a wireless LAN based on ALTAIR and have made performance measurement in terms of throughput and total output time. As a result, we observe that although the scheme does not improve the throughput performance, it is effective in suppressing an increase of the total output time due to the network delays.
{"title":"Dynamic resoltuion control of stored video traffic in a wireless LAN","authors":"S. Tasaka, H. Imura","doi":"10.1109/PIMRC.1996.567535","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567535","url":null,"abstract":"This paper describes an experiment of a temporal resolution control scheme of stored video traffic in a wireless LAN. The scheme switches the resolution between two levels according to the network load. We propose a simple method of detecting network congestion which uses only local information. We have implemented the scheme on a wireless LAN based on ALTAIR and have made performance measurement in terms of throughput and total output time. As a result, we observe that although the scheme does not improve the throughput performance, it is effective in suppressing an increase of the total output time due to the network delays.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125908043","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.568487
R. Zaffino
Through the 1980s the principal emphasis of cellular mobile radio services was on providing basic telephone communications to vehicular users over fairly large geographic areas. Initial wireless systems met a basic user need and cellular telephony became a comfortable and useful tool for managing the general business needs of mobile users. More recently, technology and manufacturing innovations have reduced the size and power requirements of mobile handsets, with the result that the larger non-vehicular population of users has been drawn to wireless communications. However, one subset of this population-in building users-has communications needs which are not adequately addressed through basic communications alone. This paper discusses the communications needs of premises users, describes several architectures for providing in building wireless services and provides an overview of access and network technologies which can be used to realize seamless in building services as an integral part of a macro network services environment.
{"title":"Wireless premises services using TDMA and the wireless intelligent network","authors":"R. Zaffino","doi":"10.1109/PIMRC.1996.568487","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.568487","url":null,"abstract":"Through the 1980s the principal emphasis of cellular mobile radio services was on providing basic telephone communications to vehicular users over fairly large geographic areas. Initial wireless systems met a basic user need and cellular telephony became a comfortable and useful tool for managing the general business needs of mobile users. More recently, technology and manufacturing innovations have reduced the size and power requirements of mobile handsets, with the result that the larger non-vehicular population of users has been drawn to wireless communications. However, one subset of this population-in building users-has communications needs which are not adequately addressed through basic communications alone. This paper discusses the communications needs of premises users, describes several architectures for providing in building wireless services and provides an overview of access and network technologies which can be used to realize seamless in building services as an integral part of a macro network services environment.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129675934","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567527
X. H. Chen, T. Lang, J. Oksman
This paper studies several algorithms for constructing quasi-optimal m-sequence subfamilies in terms of minimized BER under co-channel interference. The results show that the performance of resultant sub-families is sensitive to the sub-family sizes and the algorithms employed. A new criterion based on combinational (even plus odd) maximum cross-correlation for the code selection is introduced, based on which both highest-peak-deleting and most-peak-deleting algorithms are effective to construct the quasi-optimal subfamilies.
{"title":"Searching for quasi-optimal subfamilies of m-sequences for CDMA systems","authors":"X. H. Chen, T. Lang, J. Oksman","doi":"10.1109/PIMRC.1996.567527","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567527","url":null,"abstract":"This paper studies several algorithms for constructing quasi-optimal m-sequence subfamilies in terms of minimized BER under co-channel interference. The results show that the performance of resultant sub-families is sensitive to the sub-family sizes and the algorithms employed. A new criterion based on combinational (even plus odd) maximum cross-correlation for the code selection is introduced, based on which both highest-peak-deleting and most-peak-deleting algorithms are effective to construct the quasi-optimal subfamilies.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130048363","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567532
H. Olofsson, S. Magnusson, M. Almgren
In the near future, capacity needs will lead to cellular systems with a complex mixture of cells with different sizes and unpredictable coverage areas. Such complex systems will increase the need for manual radio network planning dramatically, unless intelligent tools are developed to assist in the planning. This paper addresses the problem of determining which cells are neighbors to a certain cell in a TDMA system. At present this has to be manually determined for each cell in a system. A concept is proposed where the neighbor cell lists are dynamically planned during system operation, with little or no manual assistance. The proposed class of algorithms uses information about the long term network behavior, and the neighbor cell lists are continuously updated. The proposed concept considerably reduces manual planning, and simulation results show that the scheme also improves the overall system quality by reducing the length of the neighbor cell lists.
{"title":"A concept for dynamic neighbor cell list planning in a cellular system","authors":"H. Olofsson, S. Magnusson, M. Almgren","doi":"10.1109/PIMRC.1996.567532","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567532","url":null,"abstract":"In the near future, capacity needs will lead to cellular systems with a complex mixture of cells with different sizes and unpredictable coverage areas. Such complex systems will increase the need for manual radio network planning dramatically, unless intelligent tools are developed to assist in the planning. This paper addresses the problem of determining which cells are neighbors to a certain cell in a TDMA system. At present this has to be manually determined for each cell in a system. A concept is proposed where the neighbor cell lists are dynamically planned during system operation, with little or no manual assistance. The proposed class of algorithms uses information about the long term network behavior, and the neighbor cell lists are continuously updated. The proposed concept considerably reduces manual planning, and simulation results show that the scheme also improves the overall system quality by reducing the length of the neighbor cell lists.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130203937","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567449
T. Vu, N. Lam, H. Chen, G. Jonas, T. Millett
The PCN/cordless/mobile communications industry has experienced an extraordinary growth in the last few years, with prediction of a worldwide subscriber population of 900 million by the year 2010. To successfully cater for this huge market, new technologies must be developed to greatly improve the system capacity within the constraint of the limited availability of the RF spectrum. One way of increasing the system capacity is to adopt more sophisticated frequency re-use scheme via the use of smart directional base-station antennas that can automatically adapt themselves to the changing mobile environment to minimise the interference from adjacent channels, co-channels, etc. For a DSP-based phased array where the signal from each array element is downconverted to a very low frequency for digitisation and then directly processed to realise various beam-forming algorithms, a parallel-processing architecture represents the most choice. This paper focuses on the implementation of such an architecture based on the TMS320C40 platform.
{"title":"A tracking antenna based on a parallel DSP architecture","authors":"T. Vu, N. Lam, H. Chen, G. Jonas, T. Millett","doi":"10.1109/PIMRC.1996.567449","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567449","url":null,"abstract":"The PCN/cordless/mobile communications industry has experienced an extraordinary growth in the last few years, with prediction of a worldwide subscriber population of 900 million by the year 2010. To successfully cater for this huge market, new technologies must be developed to greatly improve the system capacity within the constraint of the limited availability of the RF spectrum. One way of increasing the system capacity is to adopt more sophisticated frequency re-use scheme via the use of smart directional base-station antennas that can automatically adapt themselves to the changing mobile environment to minimise the interference from adjacent channels, co-channels, etc. For a DSP-based phased array where the signal from each array element is downconverted to a very low frequency for digitisation and then directly processed to realise various beam-forming algorithms, a parallel-processing architecture represents the most choice. This paper focuses on the implementation of such an architecture based on the TMS320C40 platform.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122030934","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.568430
Shiuh-Ku Weng, Jyi-Chang Tsai, C. Hsieh, Yue-Dar Jou
This paper presents a new DCT-based intraframe coding algorithm. The algorithm exploits the interblock correlation by grouping the similar blocks in an image into a category. The center of a category is then encoded with the JPEG algorithm. Simulation results indicate that the proposed algorithm improves the compression efficiency significantly at low bit rate, as compared to JPEG.
{"title":"DCT-based intraframe coding using block grouping algorithm","authors":"Shiuh-Ku Weng, Jyi-Chang Tsai, C. Hsieh, Yue-Dar Jou","doi":"10.1109/PIMRC.1996.568430","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.568430","url":null,"abstract":"This paper presents a new DCT-based intraframe coding algorithm. The algorithm exploits the interblock correlation by grouping the similar blocks in an image into a category. The center of a category is then encoded with the JPEG algorithm. Simulation results indicate that the proposed algorithm improves the compression efficiency significantly at low bit rate, as compared to JPEG.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121242892","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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