Pub Date : 1997-09-01DOI: 10.1109/PIMRC.1997.627079
B. Jones, D. Skellern
HIPERLAN is a high speed wireless LAN standard adopted by the ETSI. It operates in 150 MHz of spectrum in the 5 GHz band, with up to five TDD channels provided for duplex data transmission at up to 23.5 Mb/s. This paper shows that in the presence of cochannel cells and full link utilisation, HIPERLAN performs poorly when using its DCA-type clear channel assessment (CCA) scheme, and that the target performance levels are only achievable under optimal FCA-type channel assignments. Two main factors contribute to this poor performance: HIPERLAN has insufficient channels to meet C/I constraints in the presence of cochannel cells; and the CCA scheme results in poor channel distributions.
{"title":"HIPERLAN system performance under DCA and FCA","authors":"B. Jones, D. Skellern","doi":"10.1109/PIMRC.1997.627079","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.627079","url":null,"abstract":"HIPERLAN is a high speed wireless LAN standard adopted by the ETSI. It operates in 150 MHz of spectrum in the 5 GHz band, with up to five TDD channels provided for duplex data transmission at up to 23.5 Mb/s. This paper shows that in the presence of cochannel cells and full link utilisation, HIPERLAN performs poorly when using its DCA-type clear channel assessment (CCA) scheme, and that the target performance levels are only achievable under optimal FCA-type channel assignments. Two main factors contribute to this poor performance: HIPERLAN has insufficient channels to meet C/I constraints in the presence of cochannel cells; and the CCA scheme results in poor channel distributions.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"29 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":"129325856","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.1997.630949
A. Grimaldi, S. Marano, C. Mastroianni, M. Scarpelli
Future cellular systems are expected to use differently sized and shaped cells, depending on the area to be covered (urban or rural) and the user density. This paper proposes a cellular system that uses a two-tier cellular scheme, with macrocells and microcells. Mobile users are grouped into two classes, "slow" and "fast" users: to estimate user speed, a procedure is implemented, based on the evaluation of the amount of time a mobile station resides in a microcell. A channel assignment strategy, which tries to allocate "slow" users to the low tier (microcells) and "fast" users to the high tier (macrocells), is proposed: in this way, low mobility users undergo handovers at microcell boundaries, and high mobility users undergo handovers at macrocell boundaries. A simulation study is carried out to show that the handover rate, as well as the system signaling load, are kept at an acceptable level.
{"title":"A macro-microcellular system with mobile user speed estimation","authors":"A. Grimaldi, S. Marano, C. Mastroianni, M. Scarpelli","doi":"10.1109/PIMRC.1997.630949","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.630949","url":null,"abstract":"Future cellular systems are expected to use differently sized and shaped cells, depending on the area to be covered (urban or rural) and the user density. This paper proposes a cellular system that uses a two-tier cellular scheme, with macrocells and microcells. Mobile users are grouped into two classes, \"slow\" and \"fast\" users: to estimate user speed, a procedure is implemented, based on the evaluation of the amount of time a mobile station resides in a microcell. A channel assignment strategy, which tries to allocate \"slow\" users to the low tier (microcells) and \"fast\" users to the high tier (macrocells), is proposed: in this way, low mobility users undergo handovers at microcell boundaries, and high mobility users undergo handovers at macrocell boundaries. A simulation study is carried out to show that the handover rate, as well as the system signaling load, are kept at an acceptable level.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"2 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":"130682087","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.1997.631118
P. Diaz, J. Olmos, I. Berberana, F. Casadevall
An overview of the main characteristics of the real time emulator (RTE) to be implemented in the context of the Rainbow project is presented. First of all, the RTE functional description is shown in order to justify the rationality of the envisaged approach. Next, a description of the emulation and simulation models used in the RTE for CoDiT is provided. Off-line simulation models are used to estimate the parameters to be employed in the emulation of the different scenarios, while the use of emulation models allows for a reduction of the RTE complexity.
{"title":"Modelling approach used in the real time emulator of the Rainbow demonstrator","authors":"P. Diaz, J. Olmos, I. Berberana, F. Casadevall","doi":"10.1109/PIMRC.1997.631118","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.631118","url":null,"abstract":"An overview of the main characteristics of the real time emulator (RTE) to be implemented in the context of the Rainbow project is presented. First of all, the RTE functional description is shown in order to justify the rationality of the envisaged approach. Next, a description of the emulation and simulation models used in the RTE for CoDiT is provided. Off-line simulation models are used to estimate the parameters to be employed in the emulation of the different scenarios, while the use of emulation models allows for a reduction of the RTE complexity.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"80 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":"123348029","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.1997.626986
F. Santucci, W. Huang, V. Bhargava
An analysis of the user membership in a cellular CDMA network is proposed. It is based on the estimate of the local mean attenuation on the radio links from a mobile terminal to each of the surrounding base stations. The estimate is carried out through proper filtering of the sequences of signal strength measurements performed on the received pilot signals. Two performance measures are considered: the probability that the best base station will not be selected, and the average number of membership switchings per time unit. Assuming a channel model with log-normal shadowing and fast fading superimposed, it is seen that a proper choice of the filter parameters is required to achieve the lowest values for these performance measures. The results obtained are of interest for handover and power control algorithms.
{"title":"Analysis of user membership in cellular CDMA networks","authors":"F. Santucci, W. Huang, V. Bhargava","doi":"10.1109/PIMRC.1997.626986","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.626986","url":null,"abstract":"An analysis of the user membership in a cellular CDMA network is proposed. It is based on the estimate of the local mean attenuation on the radio links from a mobile terminal to each of the surrounding base stations. The estimate is carried out through proper filtering of the sequences of signal strength measurements performed on the received pilot signals. Two performance measures are considered: the probability that the best base station will not be selected, and the average number of membership switchings per time unit. Assuming a channel model with log-normal shadowing and fast fading superimposed, it is seen that a proper choice of the filter parameters is required to achieve the lowest values for these performance measures. The results obtained are of interest for handover and power control algorithms.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"8 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":"114332357","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.1997.627038
H. C. Lee, Junping Sun
This paper presents a multilayered mobile tracking strategy. The resource needed to page a mobile station in a mobile telephone system is a major contributor of the forward control channel (FOCC) bottleneck problem. In order to minimize the paging cost and to maximize utilization of the bandwidth in the FOCC, a new paging strategy with multilayered paging areas is presented. By using mobility pattern changes in both time and location, multilayered optimal paging zones are derived such that the paging cost to locate a mobile station (MS) is minimized.
{"title":"Multilayered model strategy for optimal mobile location tracking","authors":"H. C. Lee, Junping Sun","doi":"10.1109/PIMRC.1997.627038","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.627038","url":null,"abstract":"This paper presents a multilayered mobile tracking strategy. The resource needed to page a mobile station in a mobile telephone system is a major contributor of the forward control channel (FOCC) bottleneck problem. In order to minimize the paging cost and to maximize utilization of the bandwidth in the FOCC, a new paging strategy with multilayered paging areas is presented. By using mobility pattern changes in both time and location, multilayered optimal paging zones are derived such that the paging cost to locate a mobile station (MS) is minimized.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"106 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":"114786438","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.1997.630912
C. Tellambura, Y. Guo, S. Barton
A fast computation method for the tap weights of a linear equaliser is developed. By approximating the channel autocorrelation matrix, which has a Toeplitz structure, by a circulant matrix, the tap weights can be solved via discrete fourier transform (DFT) techniques. For an equaliser with N taps, the approximate tap weights approach the exact tap weights as N/spl rarr//spl infin/. Excess mean-square error and bit error rate (BER) degradation caused by the approximate tap weights are computed for a representative channel.
{"title":"A noniterative approach for computing linear equaliser tap weights","authors":"C. Tellambura, Y. Guo, S. Barton","doi":"10.1109/PIMRC.1997.630912","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.630912","url":null,"abstract":"A fast computation method for the tap weights of a linear equaliser is developed. By approximating the channel autocorrelation matrix, which has a Toeplitz structure, by a circulant matrix, the tap weights can be solved via discrete fourier transform (DFT) techniques. For an equaliser with N taps, the approximate tap weights approach the exact tap weights as N/spl rarr//spl infin/. Excess mean-square error and bit error rate (BER) degradation caused by the approximate tap weights are computed for a representative channel.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"315 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":"124470075","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.1997.631045
K. Arimochi, S. Sampei, N. Morinaga
This paper proposes an adaptive modulation system (AMS) with a discrete power control combined with a predistortion (PD)-type nonlinear distortion compensation technique for high quality and high power efficient high-bit-rate wireless communication systems. In the PD-type nonlinear distortion compensator, predistortion look-up table is updated using a teaching signal embedded in the guard time. In this process, nonlinear input signal vs. output distortion performance is discretely measured during the guard time period, and at the end of the guard time, a sequence of the measured distortion is interpolated using a cubic spline function to reduce memory size and the number of computation. More over, in the power control section, three levels of transmitter power attenuation, i.e., 0, 10 and 20 dB are prepared, and they are selected according to the expected carrier power to noise power spectral density (C/N/sub 0/) of the transmitter. Computer simulation confirms that the proposed method can sufficiently suppress the non-linear distortion in the adaptive modulation TDMA/TDD systems.
{"title":"Adaptive modulation system with discrete power control and predistortion-type nonlinear compensation for high spectral efficient and high power efficient wireless communication systems","authors":"K. Arimochi, S. Sampei, N. Morinaga","doi":"10.1109/PIMRC.1997.631045","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.631045","url":null,"abstract":"This paper proposes an adaptive modulation system (AMS) with a discrete power control combined with a predistortion (PD)-type nonlinear distortion compensation technique for high quality and high power efficient high-bit-rate wireless communication systems. In the PD-type nonlinear distortion compensator, predistortion look-up table is updated using a teaching signal embedded in the guard time. In this process, nonlinear input signal vs. output distortion performance is discretely measured during the guard time period, and at the end of the guard time, a sequence of the measured distortion is interpolated using a cubic spline function to reduce memory size and the number of computation. More over, in the power control section, three levels of transmitter power attenuation, i.e., 0, 10 and 20 dB are prepared, and they are selected according to the expected carrier power to noise power spectral density (C/N/sub 0/) of the transmitter. Computer simulation confirms that the proposed method can sufficiently suppress the non-linear distortion in the adaptive modulation TDMA/TDD systems.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"53 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":"126541445","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.1997.627078
M. Ruggieri
The paper proposes a design methodology for the development of wideband wireless local area networks. The approach moves from a modeling environment where the value of a properly defined cost-to-benefit of the system is adopted to measure the design effectiveness. A possible design tool consists of performance charts where the design requirements are related to the model parameters and hence, to the system parameters. The general design formulation and the performance charts are presented.
{"title":"Design of wideband wireless LANs through performance charts","authors":"M. Ruggieri","doi":"10.1109/PIMRC.1997.627078","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.627078","url":null,"abstract":"The paper proposes a design methodology for the development of wideband wireless local area networks. The approach moves from a modeling environment where the value of a properly defined cost-to-benefit of the system is adopted to measure the design effectiveness. A possible design tool consists of performance charts where the design requirements are related to the model parameters and hence, to the system parameters. The general design formulation and the performance charts are presented.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126571614","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.1997.624378
F. Layer, R. Kattenbach, H. Früchting
For investigations on channel characteristics in a deterministic indoor environment, a ray-tracing-based wideband wave propagation model with moving receiver is proposed. Considering multiple reflections and transmissions to be basic propagation effects inside buildings, the space-variant complex channel impulse response and the scattering function are calculated and compared to wideband measurements at 1800 MHz carried out in a shelter. Good agreement was found for delay times, detection of propagation paths and general characteristics of the impulse responses both for the LOS and NLOS cases. Yet, especially the magnitudes in the NLOS case suffer, for example, from uncertainties caused by an arbitrary choice of material parameters. Further investigations have to show, whether it is possible to apply the model to less deterministic environments.
{"title":"Ray optical approach for a wideband indoor wave propagation model with moving receiver","authors":"F. Layer, R. Kattenbach, H. Früchting","doi":"10.1109/PIMRC.1997.624378","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.624378","url":null,"abstract":"For investigations on channel characteristics in a deterministic indoor environment, a ray-tracing-based wideband wave propagation model with moving receiver is proposed. Considering multiple reflections and transmissions to be basic propagation effects inside buildings, the space-variant complex channel impulse response and the scattering function are calculated and compared to wideband measurements at 1800 MHz carried out in a shelter. Good agreement was found for delay times, detection of propagation paths and general characteristics of the impulse responses both for the LOS and NLOS cases. Yet, especially the magnitudes in the NLOS case suffer, for example, from uncertainties caused by an arbitrary choice of material parameters. Further investigations have to show, whether it is possible to apply the model to less deterministic environments.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"33 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":"132250701","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.1997.627069
R. Tanner, D. Cruickshank
This paper presents a Volterra function based filter as the receiver for a direct-sequence-code-divisionmultiplex-access (DS-CDMA) system. The envisaged application would be cellular telephony, where the receiver will be required to be adaptive due to channel effects. The results obtained from the Volterra filter are compared against the linear minimum-meansquare-error (MMSE) filter and the nonlinear radialbasis-function (RBF) network in a stationary multipath channel. Further, the computational complexity will be investigated and compared against the MMSE.
{"title":"Volterra Based Receivers for Ds-Cdma","authors":"R. Tanner, D. Cruickshank","doi":"10.1109/PIMRC.1997.627069","DOIUrl":"https://doi.org/10.1109/PIMRC.1997.627069","url":null,"abstract":"This paper presents a Volterra function based filter as the receiver for a direct-sequence-code-divisionmultiplex-access (DS-CDMA) system. The envisaged application would be cellular telephony, where the receiver will be required to be adaptive due to channel effects. The results obtained from the Volterra filter are compared against the linear minimum-meansquare-error (MMSE) filter and the nonlinear radialbasis-function (RBF) network in a stationary multipath channel. Further, the computational complexity will be investigated and compared against the MMSE.","PeriodicalId":362340,"journal":{"name":"Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97","volume":"31 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132531618","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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