Pub Date : 1996-10-15DOI: 10.1109/PIMRC.1996.567479
G. Brasche
One major issue of the phase 2+ development of the pan-European Global System for Mobile communications (GSM) is to specify a general packet radio service (GPRS). Such a service is necessary to be able to fulfil the increased user requirements for reasonable data services. In this paper, an overview about the overall GPRS concept, its architecture and service characteristics is given. In addition, a medium access control protocol that controls access of multiple mobile stations onto the radio channel is introduced and evaluated by simulation. The protocol is mainly characterized by dynamic bandwidth allocation and its multi-slot features. Finally, conclusions are drawn and further work items are discussed.
{"title":"Evaluation of a MAC protocol proposed for a general packet radio service in GSM","authors":"G. Brasche","doi":"10.1109/PIMRC.1996.567479","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567479","url":null,"abstract":"One major issue of the phase 2+ development of the pan-European Global System for Mobile communications (GSM) is to specify a general packet radio service (GPRS). Such a service is necessary to be able to fulfil the increased user requirements for reasonable data services. In this paper, an overview about the overall GPRS concept, its architecture and service characteristics is given. In addition, a medium access control protocol that controls access of multiple mobile stations onto the radio channel is introduced and evaluated by simulation. The protocol is mainly characterized by dynamic bandwidth allocation and its multi-slot features. Finally, conclusions are drawn and further work items are discussed.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"202 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":"116390654","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.1996.567469
K. Chua, D. Wong, J. Mark
We describe the architecture design of a wireless cellular ATM access network. A MAC protocol that has been designed to take into consideration the traffic characteristics of different service classes to provide bandwidth efficiency, good QoS for real-time traffic, and reasonable QoS for non-time-critical traffic is also described.
{"title":"Design of a cellular wireless ATM access network","authors":"K. Chua, D. Wong, J. Mark","doi":"10.1109/PIMRC.1996.567469","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567469","url":null,"abstract":"We describe the architecture design of a wireless cellular ATM access network. A MAC protocol that has been designed to take into consideration the traffic characteristics of different service classes to provide bandwidth efficiency, good QoS for real-time traffic, and reasonable QoS for non-time-critical traffic is also described.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"20 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":"116514931","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.1996.568402
B. Ibrahim, H. Aghvami
In frequency selective channels, the delay-lock loop, and tracking systems derived from it are not ideal candidates for PN code tracking. This is because they are primarily designed for the AWGN channel. A tracking system designed specifically for use in frequency selective channels is presented. It is shown that with the knowledge of the channel response of the first few resolvable paths, an extended Kalman filter can be used to generate estimates of the PN code delay from the output of baseband inphase and quadrature early-late detectors, similar to those used in delay-lock loops. From computer simulation results of a practical model of the tracking system, it is shown that the tracking system is quite robust to errors in the parameters used to describe the PN code timing process. It is also shown that a simple channel noise estimation system can be used to provide the extended Kalman algorithm with reliable estimates of the channel noise. The performance of the tracking system in PN code clock drift situations is also presented.
{"title":"The performance of a direct sequence spread spectrum PN code tracking system for frequency selective channels","authors":"B. Ibrahim, H. Aghvami","doi":"10.1109/PIMRC.1996.568402","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.568402","url":null,"abstract":"In frequency selective channels, the delay-lock loop, and tracking systems derived from it are not ideal candidates for PN code tracking. This is because they are primarily designed for the AWGN channel. A tracking system designed specifically for use in frequency selective channels is presented. It is shown that with the knowledge of the channel response of the first few resolvable paths, an extended Kalman filter can be used to generate estimates of the PN code delay from the output of baseband inphase and quadrature early-late detectors, similar to those used in delay-lock loops. From computer simulation results of a practical model of the tracking system, it is shown that the tracking system is quite robust to errors in the parameters used to describe the PN code timing process. It is also shown that a simple channel noise estimation system can be used to provide the extended Kalman algorithm with reliable estimates of the channel noise. The performance of the tracking system in PN code clock drift situations is also presented.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"51 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":"127253972","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.1996.567415
M. Reed, S. S. Pietrobon
A coding scheme, termed turbo-codes was proposed, which achieves results very close to the Shannon-limit. The encoding and decoding of turbo-codes is reviewed. In particular, a comparison of the current methods used for terminating the trellis of the turbo-code are described. A novel approach to termination of the code is introduced which removes the need to transmit tail bits across the channel. A reduction in transmitted symbols by 2 percent is achieved for PCS CDMA type applications. Simulations confirm that the novel approach is better in terms of BER than other methods of termination.
{"title":"Turbo-code termination schemes and a novel alternative for short frames","authors":"M. Reed, S. S. Pietrobon","doi":"10.1109/PIMRC.1996.567415","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567415","url":null,"abstract":"A coding scheme, termed turbo-codes was proposed, which achieves results very close to the Shannon-limit. The encoding and decoding of turbo-codes is reviewed. In particular, a comparison of the current methods used for terminating the trellis of the turbo-code are described. A novel approach to termination of the code is introduced which removes the need to transmit tail bits across the channel. A reduction in transmitted symbols by 2 percent is achieved for PCS CDMA type applications. Simulations confirm that the novel approach is better in terms of BER than other methods of termination.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"76 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":"125518282","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.1996.568395
Young-Jo Lee, Dae-Joong Kim, S. Kwon, C. Kang
For mobile communication systems, the RSSE (reduced state sequence estimation) receiver must be made adaptive to learn and to track the channel parameters. This is achieved by the adaptive channel estimator. But the channel estimator using the tentative decisions has error propagation because of incorrect decisions. This paper presents a new channel estimator using the path history in the Viterbi decoder for preventing error propagation. The selection of the path history depends on the path metric as in the decoding of the Viterbi decoder in the RSSE. A discussion on the channel estimator with different adaptation algorithms such as the least mean square (LMS) algorithm and recursive least square (RLS) algorithm is provided. Results from computer simulations show that the RSSE receivers using the proposed channel estimator have better performance than the other conventional RSSE receiver, and the channel estimator with the RLS algorithm obtains adequate performance.
{"title":"The RSSE receiver with the channel estimator using the path history","authors":"Young-Jo Lee, Dae-Joong Kim, S. Kwon, C. Kang","doi":"10.1109/PIMRC.1996.568395","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.568395","url":null,"abstract":"For mobile communication systems, the RSSE (reduced state sequence estimation) receiver must be made adaptive to learn and to track the channel parameters. This is achieved by the adaptive channel estimator. But the channel estimator using the tentative decisions has error propagation because of incorrect decisions. This paper presents a new channel estimator using the path history in the Viterbi decoder for preventing error propagation. The selection of the path history depends on the path metric as in the decoding of the Viterbi decoder in the RSSE. A discussion on the channel estimator with different adaptation algorithms such as the least mean square (LMS) algorithm and recursive least square (RLS) algorithm is provided. Results from computer simulations show that the RSSE receivers using the proposed channel estimator have better performance than the other conventional RSSE receiver, and the channel estimator with the RLS algorithm obtains adequate performance.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"53 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":"120962532","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.1996.568428
Char-Horng Liu, Chia-Chi Huang
A median-rate speech delta coder with low complexity is presented in this paper. It combines the features of one-step look-ahead decision, syllabic companding, instantaneous companding, and adaptive prediction. This coder uses not only short-term prediction filter but also long-term prediction filter to estimate the current speech sample. The performance for this coder with and without pitch prediction is compared by computer simulation. Comparisons between the performance of this coder and the performance of CVSD are also included.
{"title":"A new controlled adaptive prediction delta coder for wireless PCN applications","authors":"Char-Horng Liu, Chia-Chi Huang","doi":"10.1109/PIMRC.1996.568428","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.568428","url":null,"abstract":"A median-rate speech delta coder with low complexity is presented in this paper. It combines the features of one-step look-ahead decision, syllabic companding, instantaneous companding, and adaptive prediction. This coder uses not only short-term prediction filter but also long-term prediction filter to estimate the current speech sample. The performance for this coder with and without pitch prediction is compared by computer simulation. Comparisons between the performance of this coder and the performance of CVSD are also included.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"5 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":"127982759","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.1996.567533
Yi-Bing Lin, I. Chlamtac
This paper addresses two important PCS cost and performance issues: (1) are blocking probabilities (for new call blocking, forced termination or call completion) appropriate for PCS network performance measurement? (2) Should PCS service providers offer discounts to phone calls that are force terminated? In order to do that we derive the effective call holding time distributions for complete/incomplete calls by using an analytic model. We assume that the cell residence times have a general distribution so that the measured data from the field trials, after a second order approximation, can be used to drive our model. Our study on the effective call holding time distributions indicates that (1) blocking probabilities do not provide sufficient information to evaluate the performance of a PCS network, and that output measures, such as expected effective call holding times for complete/incomplete calls, are desirable; (2) for a PCS network with moderate user mobility, the service provider can offer substantial discounts to incomplete calls (to increase the user satisfaction) without significantly reducing the profit margin. A quantitative analysis is also provided that can be used to determine the discount factor.
{"title":"Large effective call holding times for a PCS network","authors":"Yi-Bing Lin, I. Chlamtac","doi":"10.1109/PIMRC.1996.567533","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567533","url":null,"abstract":"This paper addresses two important PCS cost and performance issues: (1) are blocking probabilities (for new call blocking, forced termination or call completion) appropriate for PCS network performance measurement? (2) Should PCS service providers offer discounts to phone calls that are force terminated? In order to do that we derive the effective call holding time distributions for complete/incomplete calls by using an analytic model. We assume that the cell residence times have a general distribution so that the measured data from the field trials, after a second order approximation, can be used to drive our model. Our study on the effective call holding time distributions indicates that (1) blocking probabilities do not provide sufficient information to evaluate the performance of a PCS network, and that output measures, such as expected effective call holding times for complete/incomplete calls, are desirable; (2) for a PCS network with moderate user mobility, the service provider can offer substantial discounts to incomplete calls (to increase the user satisfaction) without significantly reducing the profit margin. A quantitative analysis is also provided that can be used to determine the discount factor.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"34 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":"128933023","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.1996.568480
K. Yeung, T. Yum, M. Choy
Since call termination as a result of handoff failure is considerably less desirable from the user's viewpoint than the blocking of a new call, a prioritized handoff scheme is essential. Especially for microcellular systems where the mobile cell boundary crossing rate is high. Therefore an efficient DCA should give priority to handoff calls. Two DCA strategies for prioritized handoff are proposed based on a DCA called BDCL (borrowing with directional channel locking): (i) FCA with BDCL for handoff calls, and (ii) BDCL with channel reservation. FCA with BDCL for handoff calls allows a handoff call to borrow a channel using BDCL strategy if no free nominal channel in the call arrival cell is available. In BDCL with channel reservation, both the new call and handoff call can use a borrowed channel. But a fixed number of nominal channels in a cell are reserved for exclusive use of handoff calls. To study the performance of the two proposed strategies, a widely accepted mobility model is adopted. Based on this model, we derive the handoff call arrival rates and channel holding time from the given mean mobile speed. The performance of the two proposed algorithms is studied by simulations and we found that they are very effective in reducing the handoff call blocking probability while not affecting the new call performance.
{"title":"Prioritized handoff strategies using channel borrowing-based dynamic channel assignment","authors":"K. Yeung, T. Yum, M. Choy","doi":"10.1109/PIMRC.1996.568480","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.568480","url":null,"abstract":"Since call termination as a result of handoff failure is considerably less desirable from the user's viewpoint than the blocking of a new call, a prioritized handoff scheme is essential. Especially for microcellular systems where the mobile cell boundary crossing rate is high. Therefore an efficient DCA should give priority to handoff calls. Two DCA strategies for prioritized handoff are proposed based on a DCA called BDCL (borrowing with directional channel locking): (i) FCA with BDCL for handoff calls, and (ii) BDCL with channel reservation. FCA with BDCL for handoff calls allows a handoff call to borrow a channel using BDCL strategy if no free nominal channel in the call arrival cell is available. In BDCL with channel reservation, both the new call and handoff call can use a borrowed channel. But a fixed number of nominal channels in a cell are reserved for exclusive use of handoff calls. To study the performance of the two proposed strategies, a widely accepted mobility model is adopted. Based on this model, we derive the handoff call arrival rates and channel holding time from the given mean mobile speed. The performance of the two proposed algorithms is studied by simulations and we found that they are very effective in reducing the handoff call blocking probability while not affecting the new call performance.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"268 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":"133525380","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.1996.567437
M. Tolonen, J. Talvitie
The performance of carrier recovery and tracking for CDMA systems was evaluated in a realistic land mobile satellite channel as function of elevation angle and pilot channel signal-to-noise ratio. The carrier frequency is recovered by an AFC loop assuming a rough estimate of the carrier frequency is available. After frequency recovery and tracking is accomplished, the residual phase error is estimated by a feedforward structure. The performance results are presented in terms of the AFC loop acquisition time, the rms frequency error and the rms phase error. The results indicate that a two-step frequency acquisition strategy is useful to reach a good compromise between short acquisition time and low rms frequency error. The worst-case acquisition times of the AFC loop were achieved at low elevations, being below 297 ms at signal-to-noise ratios of 9 dB or higher. The worst-case frequency and phase errors were also found at low elevations, being 11.4 Hz and 23.3 degrees at 9 dB SNR, respectively.
{"title":"Carrier recovery and tracking performance for CDMA land mobile satellite links","authors":"M. Tolonen, J. Talvitie","doi":"10.1109/PIMRC.1996.567437","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567437","url":null,"abstract":"The performance of carrier recovery and tracking for CDMA systems was evaluated in a realistic land mobile satellite channel as function of elevation angle and pilot channel signal-to-noise ratio. The carrier frequency is recovered by an AFC loop assuming a rough estimate of the carrier frequency is available. After frequency recovery and tracking is accomplished, the residual phase error is estimated by a feedforward structure. The performance results are presented in terms of the AFC loop acquisition time, the rms frequency error and the rms phase error. The results indicate that a two-step frequency acquisition strategy is useful to reach a good compromise between short acquisition time and low rms frequency error. The worst-case acquisition times of the AFC loop were achieved at low elevations, being below 297 ms at signal-to-noise ratios of 9 dB or higher. The worst-case frequency and phase errors were also found at low elevations, being 11.4 Hz and 23.3 degrees at 9 dB SNR, respectively.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"4 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":"130336580","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.1996.568403
M. El-Tarhuni, A. Sheikh
This paper investigates the tracking of DS/SS signals based on an adaptive filtering technique. It is shown that a previously proposed system for code acquisition is also capable of code tracking and, by performing both acquisition and tracking with the same circuitry, significant simplification in the overall DS/SS receiver is gained. Analytical results show that the proposed scheme has a good tracking performance, as measured by the hold-in time and the false alarm penalty time, and less sensitivity to variations in the received SNR compared to conventional delay lock loops (DLLs).
{"title":"On code tracking in direct sequence spread spectrum systems using adaptive filtering techniques","authors":"M. El-Tarhuni, A. Sheikh","doi":"10.1109/PIMRC.1996.568403","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.568403","url":null,"abstract":"This paper investigates the tracking of DS/SS signals based on an adaptive filtering technique. It is shown that a previously proposed system for code acquisition is also capable of code tracking and, by performing both acquisition and tracking with the same circuitry, significant simplification in the overall DS/SS receiver is gained. Analytical results show that the proposed scheme has a good tracking performance, as measured by the hold-in time and the false alarm penalty time, and less sensitivity to variations in the received SNR compared to conventional delay lock loops (DLLs).","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"83 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":"132730607","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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