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.1996.567506
T. Imai, T. Fujii
In mobile communication systems, especially digital wireless PBX systems, it is very important to clarify the service area in case of indoor base stations. However it is very difficult to estimate the propagation characteristics accurately under these environments because the indoor components, ex. wall partition, etc., are not only positioned randomly, but also made from complex materials. An indoor micro cell area prediction system, which can be easily estimate the propagation characteristics using the ray-tracing method, is proposed and its system configuration and major performance are described.
{"title":"Indoor micro cell area prediction system using ray-tracing for mobile communication systems","authors":"T. Imai, T. Fujii","doi":"10.1109/PIMRC.1996.567506","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567506","url":null,"abstract":"In mobile communication systems, especially digital wireless PBX systems, it is very important to clarify the service area in case of indoor base stations. However it is very difficult to estimate the propagation characteristics accurately under these environments because the indoor components, ex. wall partition, etc., are not only positioned randomly, but also made from complex materials. An indoor micro cell area prediction system, which can be easily estimate the propagation characteristics using the ray-tracing method, is proposed and its system configuration and major performance are described.","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":"115189211","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.1996.567399
Yung-Liang Huang, Chia-Chi Huang
This paper records our work in developing a GMSK modem with joint symbol timing recovery and frequency offset compensation capability. The received RF signal is first down converted to a low IF and then converted to complex baseband by a digital complex sampler. This baseband signal is then frequency discriminated and passed through a digital filter which in fact performs a fast Fourier transform (FFT). In other words, we apply an FFT algorithm on the frequency discriminated baseband signal in order to estimate symbol timing error and frequency offset simultaneously. The frequency offset can be estimated from the DC component of the FFT and the symbol timing error can be estimated from the phase angle of the FFT at a specified frequency which is equal to an integral multiple of half the bit rate. These two estimated parameters are then used for symbol timing recovery and frequency offset compensation. The bit error rate (BER) performance of our GMSK receiver architecture is assessed for an AWGN channel by computer simulation.
{"title":"A low IF GMSK modem architecture with joint symbol timing recovery and frequency offset compensation","authors":"Yung-Liang Huang, Chia-Chi Huang","doi":"10.1109/PIMRC.1996.567399","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567399","url":null,"abstract":"This paper records our work in developing a GMSK modem with joint symbol timing recovery and frequency offset compensation capability. The received RF signal is first down converted to a low IF and then converted to complex baseband by a digital complex sampler. This baseband signal is then frequency discriminated and passed through a digital filter which in fact performs a fast Fourier transform (FFT). In other words, we apply an FFT algorithm on the frequency discriminated baseband signal in order to estimate symbol timing error and frequency offset simultaneously. The frequency offset can be estimated from the DC component of the FFT and the symbol timing error can be estimated from the phase angle of the FFT at a specified frequency which is equal to an integral multiple of half the bit rate. These two estimated parameters are then used for symbol timing recovery and frequency offset compensation. The bit error rate (BER) performance of our GMSK receiver architecture is assessed for an AWGN channel by computer simulation.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"25 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":"115699937","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.1996.568426
R. P. Jiménez, J. A. R. Borges, David Ortega, V. M. Melián, M. J. Betancor
The design and evaluation of a modem prototype, based on FQPSK-2 modulation, is presented. Its main application is wireless infrared local area networks. The bit rate of this prototype is 2 Mb/s, but this magnitude can be taken up to 4.8 Mb/s just by substituting the quartz crystals on the oscillator and the A/D and D/A converters in the emitter low-pass filters of the receiver. The design is full-digital in order to allow its integration on a single chip. We have chosen FQPSK-2 modulation due to its high spectral efficiency (300% better than GMSK), robustness against jitter and the constant amplitude of its complex envelope. This permits the possibility of using non-linear amplifiers and reducing power consumption. This is the most important characteristic when the system is based on portable equipment, such as laptops. Finally, extensive experimental results are presented, and BER measurements of this prototype are also given.
{"title":"FQPSK-2 high speed modem for infrared wireless LAN","authors":"R. P. Jiménez, J. A. R. Borges, David Ortega, V. M. Melián, M. J. Betancor","doi":"10.1109/PIMRC.1996.568426","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.568426","url":null,"abstract":"The design and evaluation of a modem prototype, based on FQPSK-2 modulation, is presented. Its main application is wireless infrared local area networks. The bit rate of this prototype is 2 Mb/s, but this magnitude can be taken up to 4.8 Mb/s just by substituting the quartz crystals on the oscillator and the A/D and D/A converters in the emitter low-pass filters of the receiver. The design is full-digital in order to allow its integration on a single chip. We have chosen FQPSK-2 modulation due to its high spectral efficiency (300% better than GMSK), robustness against jitter and the constant amplitude of its complex envelope. This permits the possibility of using non-linear amplifiers and reducing power consumption. This is the most important characteristic when the system is based on portable equipment, such as laptops. Finally, extensive experimental results are presented, and BER measurements of this prototype are also given.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"101 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":"124673787","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.1996.567425
F. Khan, D. Zeghlache
We analyze the performance of a priority oriented multiple access mechanism for wireless PCS. The scheme supports multiple services (including data transmission in ATM cell formats) to comply with future provisions in wireless networks. Numerical results are provided (through the definition of a multi-dimensional Markov chain model for the information slot queueing process) for the proposed technique which is called priority-based multiple access (PBMA). The overall access delay due to collision resolution and information slot allocation is also extracted from a comprehensive computer simulation. Finally, we set limits on the achievable multiplexing gains with priority-based bandwidth reservation schemes by considering an ideal scheduler for the information slot allocation.
{"title":"Performance analysis of a priority oriented multiple access mechanism for wireless PCS","authors":"F. Khan, D. Zeghlache","doi":"10.1109/PIMRC.1996.567425","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567425","url":null,"abstract":"We analyze the performance of a priority oriented multiple access mechanism for wireless PCS. The scheme supports multiple services (including data transmission in ATM cell formats) to comply with future provisions in wireless networks. Numerical results are provided (through the definition of a multi-dimensional Markov chain model for the information slot queueing process) for the proposed technique which is called priority-based multiple access (PBMA). The overall access delay due to collision resolution and information slot allocation is also extracted from a comprehensive computer simulation. Finally, we set limits on the achievable multiplexing gains with priority-based bandwidth reservation schemes by considering an ideal scheduler for the information slot allocation.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"29 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":"124921257","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}
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.1996.568395
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.1996.567437
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}
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