Pub Date : 2004-12-01DOI: 10.1109/ISSSTA.2004.1371793
D. Yoshioka, A. Tsuneda, T. Inoue
We present a new criterion for selecting initial phases of maximal-period sequences which are kinds of chaos-based spreading sequences. The sequences with the phase obtained by such a criterion have advantages in asynchronous DS-CDMA with respect to deviations of cochannel interference parameters from their average value. We can select a large class of sequences with "good" properties by using the proposed criterion as a sieve.
{"title":"Initial phase selection of chaos-based spreading sequences in asynchronous DS-CDMA systems","authors":"D. Yoshioka, A. Tsuneda, T. Inoue","doi":"10.1109/ISSSTA.2004.1371793","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371793","url":null,"abstract":"We present a new criterion for selecting initial phases of maximal-period sequences which are kinds of chaos-based spreading sequences. The sequences with the phase obtained by such a criterion have advantages in asynchronous DS-CDMA with respect to deviations of cochannel interference parameters from their average value. We can select a large class of sequences with \"good\" properties by using the proposed criterion as a sieve.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124898552","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 : 2004-12-01DOI: 10.1109/ISSSTA.2004.1371750
A. C. Gordillo, G. D. de Abreu, R. Kohno
This paper addresses the design of an equally frequency limited set of orthogonal pulses adequate for an impulse radio (IR) ultra wideband (UWB) communication system employing M-ary pulse shape modulation (PSM). UWB systems have to face many spectrum restrictions due to potential interference to sensitive existing systems, comply with maximum bandwidth regulations or fit into spectrum masks like the one emitted by the Federal Communications Commission (FCC). Then, UWB systems have to restrict their bandwidth and maximize its usage efficiency. Additionally, future narrowband communication systems can be allocated in portions of the spectrum where UWB systems operate, and they may not tolerate possible interference from UWB emissions, this would lead to the mandatory use of a stop-band filter in the UWB transmitters. The proposed set of orthogonal pulse-shapes provides both pulses equally limited in frequency and robustness against such a narrowband interference canceller filter.
{"title":"Band-limited frequency efficient orthogonal pulse shape modulation for UWB communications","authors":"A. C. Gordillo, G. D. de Abreu, R. Kohno","doi":"10.1109/ISSSTA.2004.1371750","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371750","url":null,"abstract":"This paper addresses the design of an equally frequency limited set of orthogonal pulses adequate for an impulse radio (IR) ultra wideband (UWB) communication system employing M-ary pulse shape modulation (PSM). UWB systems have to face many spectrum restrictions due to potential interference to sensitive existing systems, comply with maximum bandwidth regulations or fit into spectrum masks like the one emitted by the Federal Communications Commission (FCC). Then, UWB systems have to restrict their bandwidth and maximize its usage efficiency. Additionally, future narrowband communication systems can be allocated in portions of the spectrum where UWB systems operate, and they may not tolerate possible interference from UWB emissions, this would lead to the mandatory use of a stop-band filter in the UWB transmitters. The proposed set of orthogonal pulse-shapes provides both pulses equally limited in frequency and robustness against such a narrowband interference canceller filter.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126047997","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 : 2004-12-01DOI: 10.1109/ISSSTA.2004.1371753
G. Alfano, A. Tulino, A. Lozano, S. Verdú
We present closed-form expressions for the marginal density distribution of the unordered eigenvalues of HFH* where F is an input covariance and H is a matrix representing a MIMO (multi-input multi-output) Rayleigh-faded channel with one-sided correlation at either end of the link, transmitter or receiver, with no constraints on the numbers of antennas therein. Using the foregoing distribution, we then derive analytical expressions for the capacity. The expressions found are evaluated through several examples conducted with correlation structures of practical interest.
{"title":"Capacity of MIMO channels with one-sided correlation","authors":"G. Alfano, A. Tulino, A. Lozano, S. Verdú","doi":"10.1109/ISSSTA.2004.1371753","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371753","url":null,"abstract":"We present closed-form expressions for the marginal density distribution of the unordered eigenvalues of HFH* where F is an input covariance and H is a matrix representing a MIMO (multi-input multi-output) Rayleigh-faded channel with one-sided correlation at either end of the link, transmitter or receiver, with no constraints on the numbers of antennas therein. Using the foregoing distribution, we then derive analytical expressions for the capacity. The expressions found are evaluated through several examples conducted with correlation structures of practical interest.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"2008 20","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114087031","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 : 2004-12-01DOI: 10.1109/ISSSTA.2004.1371716
A. Tsuneda, D. Yoshioka, T. Hadate
Spreading sequences with a negative auto-correlation for time-delay one are designed based on the Bernoulli and tent maps which are well-known one-dimensional chaotic maps. We also show that maximal-period binary sequences with negative auto-correlation based on such maps with finite bits can be generated by a class of nonlinear feedback shift registers (NFSRs). Furthermore, we perform computer simulations of asynchronous DS/CDMA communications using such negatively auto-correlated spreading sequences.
{"title":"Design of spreading sequences with negative auto-correlations realizable by nonlinear feedback shift registers","authors":"A. Tsuneda, D. Yoshioka, T. Hadate","doi":"10.1109/ISSSTA.2004.1371716","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371716","url":null,"abstract":"Spreading sequences with a negative auto-correlation for time-delay one are designed based on the Bernoulli and tent maps which are well-known one-dimensional chaotic maps. We also show that maximal-period binary sequences with negative auto-correlation based on such maps with finite bits can be generated by a class of nonlinear feedback shift registers (NFSRs). Furthermore, we perform computer simulations of asynchronous DS/CDMA communications using such negatively auto-correlated spreading sequences.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133584102","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 : 2004-08-30DOI: 10.1109/ISSSTA.2004.1371673
Tao Wang, Yong Wang
The jam resistance performance of UWB impulse radio with bipolar modulation and time hopping or direct sequence is analyzed in terms of the processing gain theoretically, where the jam interference is modeled as a continuous wide sense stationary random process whose bandwidth is much smaller than the impulse radio bandwidth. The general closed form expressions for the processing gain are derived, and they show when the data rate is fixed, the processing gain can be increased through decreasing the UWB pulse spectrum in the band where the jam interference lies. In particular the condition is presented to judge which spread spectrum technique can provide the superior processing gain, and a signal parameter design guide is given to improve the processing gain of time hopping impulse radio to be a prescribed extent above that of direct sequence impulse radio. Simulations demonstrate the theoretical analysis.
{"title":"Jam resistance performance of UWB BPM impulse radio with time hopping vs. direct sequence","authors":"Tao Wang, Yong Wang","doi":"10.1109/ISSSTA.2004.1371673","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371673","url":null,"abstract":"The jam resistance performance of UWB impulse radio with bipolar modulation and time hopping or direct sequence is analyzed in terms of the processing gain theoretically, where the jam interference is modeled as a continuous wide sense stationary random process whose bandwidth is much smaller than the impulse radio bandwidth. The general closed form expressions for the processing gain are derived, and they show when the data rate is fixed, the processing gain can be increased through decreasing the UWB pulse spectrum in the band where the jam interference lies. In particular the condition is presented to judge which spread spectrum technique can provide the superior processing gain, and a signal parameter design guide is given to improve the processing gain of time hopping impulse radio to be a prescribed extent above that of direct sequence impulse radio. Simulations demonstrate the theoretical analysis.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115138058","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 : 2004-08-30DOI: 10.1109/ISSSTA.2004.1371699
K. Mori, H. Kobayashi
The shared TDD scheme has been proposed for accommodation of asymmetric traffic between uplinks and downlinks. The cellular systems applying the shared-TDD scheme cause interlink interference. This paper proposes a downlink packet transmission control scheme in order to relieve the effect of interlink interference in CDMA/shared-TDD cellular packet systems. In the proposed scheme, base stations select the slots transmitting downlink packets based on both the location of receiving mobile stations and the slot allocations in the adjacent cells. Computer simulation shows that the proposed scheme relieves the effect of interlink interference, and thus improves the downlink transmission efficiency.
{"title":"Downlink packet transmission control for asymmetric traffic in CDMA/shared-TDD cellular communication systems","authors":"K. Mori, H. Kobayashi","doi":"10.1109/ISSSTA.2004.1371699","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371699","url":null,"abstract":"The shared TDD scheme has been proposed for accommodation of asymmetric traffic between uplinks and downlinks. The cellular systems applying the shared-TDD scheme cause interlink interference. This paper proposes a downlink packet transmission control scheme in order to relieve the effect of interlink interference in CDMA/shared-TDD cellular packet systems. In the proposed scheme, base stations select the slots transmitting downlink packets based on both the location of receiving mobile stations and the slot allocations in the adjacent cells. Computer simulation shows that the proposed scheme relieves the effect of interlink interference, and thus improves the downlink transmission efficiency.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"230 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123070836","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 : 2004-08-30DOI: 10.1109/ISSSTA.2004.1371717
J. Tropp, I. Dhillon, R. Heath
A description of optimal sequences for direct-sequence code division multiple access is a byproduct of recent characterizations of the sum capacity. The paper restates the sequence design problem as an inverse singular value problem and shows that it can be solved with finite-step algorithms from matrix analysis. Relevant algorithms are reviewed and a new one-sided construction is proposed that obtains the sequences directly instead of computing the Gram matrix of the optimal signatures.
{"title":"Optimal CDMA signatures: a finite-step approach","authors":"J. Tropp, I. Dhillon, R. Heath","doi":"10.1109/ISSSTA.2004.1371717","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371717","url":null,"abstract":"A description of optimal sequences for direct-sequence code division multiple access is a byproduct of recent characterizations of the sum capacity. The paper restates the sequence design problem as an inverse singular value problem and shows that it can be solved with finite-step algorithms from matrix analysis. Relevant algorithms are reviewed and a new one-sided construction is proposed that obtains the sequences directly instead of computing the Gram matrix of the optimal signatures.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116861941","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 : 2004-08-30DOI: 10.1109/ISSSTA.2004.1371775
N. Souto, J.C. Silva, A. Correia, F. Cercas, A. Rodrigues
HSDPA is the already standardized evolution of UMTS to significantly increase the data rate achieving peak values over 10 Mbit/s. This paper addresses the performance improvement of the HSDPA in multipath fading channels when using several transmitting antennas at the BS. 3GPP specifications define several transmit diversity schemes for two antennas, namely the standardized closed loop modes 1 and 2 and the open loop space time transmit diversity (STTD). This paper studies these techniques but also other transmitting schemes such as open loop modes using space time block codes (STBC) for 4 and 8 transmitting antennas, selective transmit diversity (STD) and hybrid modes combining space time block codes and STD. The performance impact of all these techniques is compared and evaluated using a HSDPA link level simulator.
{"title":"Transmit diversity schemes for high speed downlink packet access in 3.5G cellular systems","authors":"N. Souto, J.C. Silva, A. Correia, F. Cercas, A. Rodrigues","doi":"10.1109/ISSSTA.2004.1371775","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371775","url":null,"abstract":"HSDPA is the already standardized evolution of UMTS to significantly increase the data rate achieving peak values over 10 Mbit/s. This paper addresses the performance improvement of the HSDPA in multipath fading channels when using several transmitting antennas at the BS. 3GPP specifications define several transmit diversity schemes for two antennas, namely the standardized closed loop modes 1 and 2 and the open loop space time transmit diversity (STTD). This paper studies these techniques but also other transmitting schemes such as open loop modes using space time block codes (STBC) for 4 and 8 transmitting antennas, selective transmit diversity (STD) and hybrid modes combining space time block codes and STD. The performance impact of all these techniques is compared and evaluated using a HSDPA link level simulator.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117150138","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 : 2004-08-30DOI: 10.1109/ISSSTA.2004.1371813
F. Ono, H. Habuchi
A time-hopping modified pulse spacing modulation system with restricted amplitude levels is proposed. The proposed system combines multipulse pulse position modulation (MPPM) with code shift keying. The average frame length of the transmitted signal for the proposed system not only becomes shorter than that for the MPPM system, but the amplitude of the transmitted signal is restricted to 2 levels. The basic performance of the proposed system is evaluated by theoretical analysis. As a result, the data transmission rate of the proposed system is 2.4 times higher than that of the spread-spectrum pulse position modulation (SS-PPM) system. The probability of block error that takes into account the synchronization performance can reach the lower bound by making use of the preamble signal. Moreover, the spectral efficiency of the proposed system is 1.8 times greater than that of the SS-PPM system.
{"title":"Proposal of a time-hopping modified multipulse PPM system with restricted amplitude levels","authors":"F. Ono, H. Habuchi","doi":"10.1109/ISSSTA.2004.1371813","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371813","url":null,"abstract":"A time-hopping modified pulse spacing modulation system with restricted amplitude levels is proposed. The proposed system combines multipulse pulse position modulation (MPPM) with code shift keying. The average frame length of the transmitted signal for the proposed system not only becomes shorter than that for the MPPM system, but the amplitude of the transmitted signal is restricted to 2 levels. The basic performance of the proposed system is evaluated by theoretical analysis. As a result, the data transmission rate of the proposed system is 2.4 times higher than that of the spread-spectrum pulse position modulation (SS-PPM) system. The probability of block error that takes into account the synchronization performance can reach the lower bound by making use of the preamble signal. Moreover, the spectral efficiency of the proposed system is 1.8 times greater than that of the SS-PPM system.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"35 24","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120994646","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 : 2004-08-30DOI: 10.1109/ISSSTA.2004.1371802
I. Casella, E. Sousa, P. Jeszensky
Equalization post-combining with channel estimation (EPCCE) has recently been presented for applications with space-time block coding in frequency selective fading channels. In spite of offering full diversity, EPCCE can suffer from performance degradation due to imperfect channel estimate. We propose a new EPCCE receiver using decision feedback equalization (DFE) and iterative channel estimation based on inter-antenna interference cancellation in order to improve the channel estimate and the performance of the receiver when the number of training symbols is limited.
{"title":"Space-time block coding using decision feedback equalization and iterative channel estimation with inter-antenna interference cancellation","authors":"I. Casella, E. Sousa, P. Jeszensky","doi":"10.1109/ISSSTA.2004.1371802","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371802","url":null,"abstract":"Equalization post-combining with channel estimation (EPCCE) has recently been presented for applications with space-time block coding in frequency selective fading channels. In spite of offering full diversity, EPCCE can suffer from performance degradation due to imperfect channel estimate. We propose a new EPCCE receiver using decision feedback equalization (DFE) and iterative channel estimation based on inter-antenna interference cancellation in order to improve the channel estimate and the performance of the receiver when the number of training symbols is limited.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124943260","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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