Pub Date : 2004-08-30DOI: 10.1109/ISSSTA.2004.1371829
Y. Jitsumatsu, Y. Hattori, T. A. Khan, T. Kohda
In spread spectrum (SS)-based digital watermarking systems, watermark information is spread by a pseudorandom code and added to the original information signal. On the other hand, we have proposed another watermarking system having one watermark channel and several image transmission channels. Information data is modulated by SS codes with variable code length according to its significance. This paper inspects bit error rate of such a watermarking system for both watermark channel and image transmission channels.
{"title":"Bit error rate in digital watermarking systems using spread spectrum techniques","authors":"Y. Jitsumatsu, Y. Hattori, T. A. Khan, T. Kohda","doi":"10.1109/ISSSTA.2004.1371829","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371829","url":null,"abstract":"In spread spectrum (SS)-based digital watermarking systems, watermark information is spread by a pseudorandom code and added to the original information signal. On the other hand, we have proposed another watermarking system having one watermark channel and several image transmission channels. Information data is modulated by SS codes with variable code length according to its significance. This paper inspects bit error rate of such a watermarking system for both watermark channel and image transmission channels.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"31 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":"134274224","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.2004.1371744
Duong H. Pham, J. Manton
Block transmission systems with guard intervals usually either use a cyclic prefix or introduce a sequence of zeros of length greater than or equal to an upper bound of the channel memory between blocks to prevent inter-block interference. Another possibility is to transmit known symbols in the guard interval. Although this has been considered before, the proposed channel identification algorithm was computationally intensive. We propose a simpler algorithm based on first order statistics. At the receiver, the channel is estimated by first computing the mean of the relevant parts of the received blocks. To enhance the performance at high signal-to-noise ratio, we combine the first order statistical algorithm with a simple iterative source-channel estimation algorithm. There is no extra loss of information rate as opposed to training sequence based methods for systems with guard intervals, no condition imposed on the channel and no scaling ambiguity as opposed to second (or higher) order statistical or finite alphabet-based methods. Just like zero guard intervals, known symbol guard intervals guarantee free inter-block interference and channel irrespective symbol detectability.
{"title":"Channel identification using known symbol guard intervals","authors":"Duong H. Pham, J. Manton","doi":"10.1109/ISSSTA.2004.1371744","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371744","url":null,"abstract":"Block transmission systems with guard intervals usually either use a cyclic prefix or introduce a sequence of zeros of length greater than or equal to an upper bound of the channel memory between blocks to prevent inter-block interference. Another possibility is to transmit known symbols in the guard interval. Although this has been considered before, the proposed channel identification algorithm was computationally intensive. We propose a simpler algorithm based on first order statistics. At the receiver, the channel is estimated by first computing the mean of the relevant parts of the received blocks. To enhance the performance at high signal-to-noise ratio, we combine the first order statistical algorithm with a simple iterative source-channel estimation algorithm. There is no extra loss of information rate as opposed to training sequence based methods for systems with guard intervals, no condition imposed on the channel and no scaling ambiguity as opposed to second (or higher) order statistical or finite alphabet-based methods. Just like zero guard intervals, known symbol guard intervals guarantee free inter-block interference and channel irrespective symbol detectability.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"89 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":"131804488","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.2004.1371765
Jinho Choi
Low density spreading (LDS) for multicarrier (MC) systems has been proposed to exploit the trade-off between the receiver complexity and performance improvement. Due to the LSD, the diversity gain from the frequency domain can be achieved by the maximum-likelihood (ML) detector. The structured LDS allows the use of the Viterbi algorithm (VA) to implement the ML detection computationally efficiently. It is also shown that the LSD-MC can perform better than orthogonal frequency division multiplexing (OFDM) for coded signals.
{"title":"Low density spreading for multicarrier systems","authors":"Jinho Choi","doi":"10.1109/ISSSTA.2004.1371765","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371765","url":null,"abstract":"Low density spreading (LDS) for multicarrier (MC) systems has been proposed to exploit the trade-off between the receiver complexity and performance improvement. Due to the LSD, the diversity gain from the frequency domain can be achieved by the maximum-likelihood (ML) detector. The structured LDS allows the use of the Viterbi algorithm (VA) to implement the ML detection computationally efficiently. It is also shown that the LSD-MC can perform better than orthogonal frequency division multiplexing (OFDM) for coded signals.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"87 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":"116235475","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.2004.1371654
I. Collings, M. Butler, Matthew R. McKay
This paper considers multiple-input multiple-output (MIMO) systems with bit-interleaved coded modulation (BICM). Two receiver structures are considered, one based on zero-forcing, the other on minimum mean square error (MMSE). An approximate log-likelihood (ALL) decoding approach is examined in each case, for PSK and QAM. The resulting receivers are significantly lower complexity compared to the maximum likelihood (ML) receiver. We expand on previous results which showed that for the ZF-ALL receiver the performance gap, compared to ML, reduces when either the number of receive antennas or the modulation order is increased. We demonstrate that the ALL metric with BICM counteracts any noise enhancement from the linear receivers. We also show that the linear BICM schemes outperform the corresponding BLAST approaches.
{"title":"Low complexity receiver design for MIMO bit-interleaved coded modulation","authors":"I. Collings, M. Butler, Matthew R. McKay","doi":"10.1109/ISSSTA.2004.1371654","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371654","url":null,"abstract":"This paper considers multiple-input multiple-output (MIMO) systems with bit-interleaved coded modulation (BICM). Two receiver structures are considered, one based on zero-forcing, the other on minimum mean square error (MMSE). An approximate log-likelihood (ALL) decoding approach is examined in each case, for PSK and QAM. The resulting receivers are significantly lower complexity compared to the maximum likelihood (ML) receiver. We expand on previous results which showed that for the ZF-ALL receiver the performance gap, compared to ML, reduces when either the number of receive antennas or the modulation order is increased. We demonstrate that the ALL metric with BICM counteracts any noise enhancement from the linear receivers. We also show that the linear BICM schemes outperform the corresponding BLAST approaches.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"18 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":"123444173","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.2004.1371830
Kegen Yu, I. Oppermann
We investigate the outage probability of a multiuser receiver in fading channels. We focus on the multipath, Nakagami-m channels with arbitrary m and path powers. Approximate analytical expressions of the outage probability of the linear minimum mean-squared error (LMMSE) receiver are derived when the receiver employs the channel gain variances of the interferers. In deriving the analytical expressions, we exploit large system analysis and the gamma series representation of the probability density function (PDF) of a sum of independent gamma variables. The outage probability is evaluated under a range of receiver implementations. The accuracy of the theoretical results is examined through simulation.
{"title":"Outage probability of LMMSE receiver in multipath Nakagami-m fading channels","authors":"Kegen Yu, I. Oppermann","doi":"10.1109/ISSSTA.2004.1371830","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371830","url":null,"abstract":"We investigate the outage probability of a multiuser receiver in fading channels. We focus on the multipath, Nakagami-m channels with arbitrary m and path powers. Approximate analytical expressions of the outage probability of the linear minimum mean-squared error (LMMSE) receiver are derived when the receiver employs the channel gain variances of the interferers. In deriving the analytical expressions, we exploit large system analysis and the gamma series representation of the probability density function (PDF) of a sum of independent gamma variables. The outage probability is evaluated under a range of receiver implementations. The accuracy of the theoretical results is examined through simulation.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"67 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":"126142455","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: 10.1093/ietfec/e88-a.10.2669
H. Fujisaki, Yosuke Yamada
We discuss evaluations of bit error probabilities in SSMA (spread spectrum multiple access) communication systems using binary spreading sequences of Markov chains and the designing of binary spreading sequences of Markov chains optimal in terms of bit error probabilities. We study SSMA communication systems using binary spreading sequences of Markov chains and give a necessary and sufficient condition that the distribution of the normalized MAI (multiple-access interference) is Gaussian. Based on this result, we discuss theoretical evaluations of bit error probabilities in such systems based on the CLT (central limit theorem) and those based on the SGA (standard Gaussian approximation). We compare these theoretical evaluations with experimental results and also discuss the optimum spreading sequences of Markov chains in terms of bit error probabilities based on the CLT.
{"title":"On bit error probabilities of SSMA communication systems using spreading sequences of Markov chains","authors":"H. Fujisaki, Yosuke Yamada","doi":"10.1093/ietfec/e88-a.10.2669","DOIUrl":"https://doi.org/10.1093/ietfec/e88-a.10.2669","url":null,"abstract":"We discuss evaluations of bit error probabilities in SSMA (spread spectrum multiple access) communication systems using binary spreading sequences of Markov chains and the designing of binary spreading sequences of Markov chains optimal in terms of bit error probabilities. We study SSMA communication systems using binary spreading sequences of Markov chains and give a necessary and sufficient condition that the distribution of the normalized MAI (multiple-access interference) is Gaussian. Based on this result, we discuss theoretical evaluations of bit error probabilities in such systems based on the CLT (central limit theorem) and those based on the SGA (standard Gaussian approximation). We compare these theoretical evaluations with experimental results and also discuss the optimum spreading sequences of Markov chains in terms of bit error probabilities based on the CLT.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"20 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":"130162267","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.2004.1371660
Xia Wang, Shihua Zhu, Delong Sun
Based on an analysis of the cochannel interference (CCI) pattern of a frequency hopped multiple access signal, the paper proposes a new multiuser detection algorithm for canceling the CCI in frequency hopped multiple access systems. In the proposed scheme, the CCI is cancelled by first detecting the frequency hopping slot, and then classifying and regenerating the candidates of the interference pattern from the time-frequency matrix. Both theoretical analysis and computer simulation results show that, compared to the conventional detector and Mabuchi's detector, this new multiuser detector has lower complexity, better convergence stability, and is suitable for both additive white Gaussian noise (AWGN) channels and Rayleigh fading channels.
{"title":"Cochannel interference cancellation for frequency hopped multiple access systems","authors":"Xia Wang, Shihua Zhu, Delong Sun","doi":"10.1109/ISSSTA.2004.1371660","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371660","url":null,"abstract":"Based on an analysis of the cochannel interference (CCI) pattern of a frequency hopped multiple access signal, the paper proposes a new multiuser detection algorithm for canceling the CCI in frequency hopped multiple access systems. In the proposed scheme, the CCI is cancelled by first detecting the frequency hopping slot, and then classifying and regenerating the candidates of the interference pattern from the time-frequency matrix. Both theoretical analysis and computer simulation results show that, compared to the conventional detector and Mabuchi's detector, this new multiuser detector has lower complexity, better convergence stability, and is suitable for both additive white Gaussian noise (AWGN) channels and Rayleigh fading channels.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"1 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":"129446319","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.2004.1371783
A. Pouttu, H. Saarnisaari, S. Glisic
We propose and analyse the performance of the coherent mMCSK-mMFSK modulation technique. The technique combines CSK and FSK modulation formats. The mMFSK component apart from data modulation is also used to decide the number of frequencies of mf signal to be transmitted. On each of these frequencies a number of codes mc of a even larger set of codes is transmitted. The technique offers high data rate capabilities and the performance compared to other modulation formats of the same order is excellent.
{"title":"mMCSK-mMFSK modulation","authors":"A. Pouttu, H. Saarnisaari, S. Glisic","doi":"10.1109/ISSSTA.2004.1371783","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371783","url":null,"abstract":"We propose and analyse the performance of the coherent mMCSK-mMFSK modulation technique. The technique combines CSK and FSK modulation formats. The mMFSK component apart from data modulation is also used to decide the number of frequencies of mf signal to be transmitted. On each of these frequencies a number of codes mc of a even larger set of codes is transmitted. The technique offers high data rate capabilities and the performance compared to other modulation formats of the same order is excellent.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"78 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":"126307808","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.2004.1371832
L. Shang, Z. M. Hussain, R. Harris
Blind source separation (BSS) based on time-frequency distributions (TFD) has certain advantages over other methods, such as allowing the separation of Gaussian sources with identical spectral shape but different t-f localization properties. However, quadratic TFD, which are the most important class of TFD suitable for this approach, differ widely in resolution and ability to reduce the cross-terms that disturb the signal interpretation. This paper investigates the performance of different time-frequency distributions on the blind separation of speech signals and nonlinear FM signals. We also discuss the possibility and the suitability of the solution to convolutive mixture of the speech signals using time-frequency based blind source separation because of its ability to process complex-valued signals.
{"title":"Performance of quadratic time-frequency distributions in blind source separation of speech signals","authors":"L. Shang, Z. M. Hussain, R. Harris","doi":"10.1109/ISSSTA.2004.1371832","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371832","url":null,"abstract":"Blind source separation (BSS) based on time-frequency distributions (TFD) has certain advantages over other methods, such as allowing the separation of Gaussian sources with identical spectral shape but different t-f localization properties. However, quadratic TFD, which are the most important class of TFD suitable for this approach, differ widely in resolution and ability to reduce the cross-terms that disturb the signal interpretation. This paper investigates the performance of different time-frequency distributions on the blind separation of speech signals and nonlinear FM signals. We also discuss the possibility and the suitability of the solution to convolutive mixture of the speech signals using time-frequency based blind source separation because of its ability to process complex-valued signals.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"252 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":"121138232","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.2004.1371731
L. Krikidis, J. Danger, L. Naviner
Third generation (3G) mobile communication systems can provide high data rates with spectrum efficiency over multipath fading channels. In order to make that feasible, they use low processing gains while maintaining a fixed bandwidth. For the lowest spreading gains, multiple access interference (MAI) can be considered low and inter-path interference (IPI) becomes the principal factor for performance degradation of the conventional RAKE receiver. We adapt the approach of interference cancellation, a well-known technique for multiuser detection, to mitigate the effects of self-interference in a single-user direct sequence code division multiple access (DS-CDMA) system over high data rate connections. We introduce an interference canceller (IC) which aims to improve system performance by regenerating, and then subtracting, estimates of the interfering signals, embedded in the initial correlator output, and channel estimation. By repeating this operation in a multi-stage scheme, we can improve system performance significantly at high data rates. Also, we propose an architecture for this repeating cancellation scheme and we discuss its calculated power requirements.
{"title":"A DS-CDMA multi-stage inter-path interference canceller for high bit rates","authors":"L. Krikidis, J. Danger, L. Naviner","doi":"10.1109/ISSSTA.2004.1371731","DOIUrl":"https://doi.org/10.1109/ISSSTA.2004.1371731","url":null,"abstract":"Third generation (3G) mobile communication systems can provide high data rates with spectrum efficiency over multipath fading channels. In order to make that feasible, they use low processing gains while maintaining a fixed bandwidth. For the lowest spreading gains, multiple access interference (MAI) can be considered low and inter-path interference (IPI) becomes the principal factor for performance degradation of the conventional RAKE receiver. We adapt the approach of interference cancellation, a well-known technique for multiuser detection, to mitigate the effects of self-interference in a single-user direct sequence code division multiple access (DS-CDMA) system over high data rate connections. We introduce an interference canceller (IC) which aims to improve system performance by regenerating, and then subtracting, estimates of the interfering signals, embedded in the initial correlator output, and channel estimation. By repeating this operation in a multi-stage scheme, we can improve system performance significantly at high data rates. Also, we propose an architecture for this repeating cancellation scheme and we discuss its calculated power requirements.","PeriodicalId":340769,"journal":{"name":"Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738)","volume":"15 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":"115342126","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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