CDMA通信系统中盲多用户检测技术的研究
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摘要
在码分多址(CDMA)系统中多个用户均占用同一时隙、同一频隙,不同的是选取的地址码不相同,在实际应用中,地址码又不可能达到理想的状态,因此在多个用户通信时,一定会产生多址干扰(MAI)。随着用户数目的不断变化,多址干扰就成为CDMA系统中最主要的干扰。多用户检测技术则是充分利用所有用户的信息来做检测,抑制多址干扰,提高系统的容量,解决了远近效应问题。在实际应用中要求多用户检测算法既能满足性能优良又能满足复杂度低,然而现有的多用户检测技术还不能在这两者之间取得平衡,因此有必要对多用户检测进行更深入细致的研究。
本文首先对直接序列扩频码分多址(DS-CDMA)系统的多用户检测技术的理论与技术进行系统的介绍,然后从最原始的传统检测机到盲自适应检测机进行介绍,并对多用户检测的应用及应用前景进行探讨,对线性盲自适应多用户检测算法进行具体的比较和分析。在此基础上,本文给出了一种改进的基于压缩预测逼近子空间跟踪算法(iPASTd),以及一种基于改进的压缩预测逼近算法(iPASTd)和Kalman滤波相结合的盲自适应多用户的检测器。仿真实验结果表明,本文给出的盲自适应多用户检测器与基于最小二乘(RLS)算法的盲自适应多用户检测器和基于最小均方(LMS)算法的盲自适应多用户检测器相比较具有良好的跟踪性能,较低的复杂度,在加性高斯白噪声(AWGN)信道中取得良好的信干比,并且在高信噪比和强远近效应的情况下,本文给出的盲自适应多用户检测器能实现更快的全局收敛并且具有良好的跟踪性能。
In the CDMA system multiple users are housed in the same slot and the same band gap, but select a different address code.In practice, the address code can not possibly meet ideal conditions. when multiple users communicating, it will produce multiple access interference (MAI). With the changing number of users, multiple access interference has become the most important interference in CDMA systems. Multi-user detection technology is the full use of all user information to perform detection, suppress multiple access interference and increase system capacity. In practice multi-user detection algorithm is required to meet for both excellent performance and can meet the low complexity, while the natural existing multi-user detection techniques can not achieve balance between these two. Hence the need for more multi-user detection intensive research.
First the article introduce multiuser detection theory and technology in DS-CDMA systems. Then the most primitive from to the traditional blind adaptive detector testing machines are introduced in the paper. The application and the application prospect of multi-user detection will be introduced in the paper, then the paper will do a specific comparison and analysis for linear blind adaptive multiuser detection algorithm. On this basis, the paper gives an improved prediction based compression approximation subspace tracking algorithm (iPASTd), as well as an improved forecast based on improved approximation algorithm for the compression (iPASTd) and the Kalman filter combining blind adaptive multi-user detector. Simulation results show that given the blind adaptive multiuser detection algorithm based on RLS blind adaptive multiuser detector, and based on LMS algorithm for blind adaptive multiuser detector compared with a good tracking performance, lower complexity, in the AWGN channel to obtain a good signal to interference ratio, and high SNR and strong near-far situation, this paper, blind adaptive multiuser detector can achieve a faster global convergence and good tracking performance.
本文首先对直接序列扩频码分多址(DS-CDMA)系统的多用户检测技术的理论与技术进行系统的介绍,然后从最原始的传统检测机到盲自适应检测机进行介绍,并对多用户检测的应用及应用前景进行探讨,对线性盲自适应多用户检测算法进行具体的比较和分析。在此基础上,本文给出了一种改进的基于压缩预测逼近子空间跟踪算法(iPASTd),以及一种基于改进的压缩预测逼近算法(iPASTd)和Kalman滤波相结合的盲自适应多用户的检测器。仿真实验结果表明,本文给出的盲自适应多用户检测器与基于最小二乘(RLS)算法的盲自适应多用户检测器和基于最小均方(LMS)算法的盲自适应多用户检测器相比较具有良好的跟踪性能,较低的复杂度,在加性高斯白噪声(AWGN)信道中取得良好的信干比,并且在高信噪比和强远近效应的情况下,本文给出的盲自适应多用户检测器能实现更快的全局收敛并且具有良好的跟踪性能。
In the CDMA system multiple users are housed in the same slot and the same band gap, but select a different address code.In practice, the address code can not possibly meet ideal conditions. when multiple users communicating, it will produce multiple access interference (MAI). With the changing number of users, multiple access interference has become the most important interference in CDMA systems. Multi-user detection technology is the full use of all user information to perform detection, suppress multiple access interference and increase system capacity. In practice multi-user detection algorithm is required to meet for both excellent performance and can meet the low complexity, while the natural existing multi-user detection techniques can not achieve balance between these two. Hence the need for more multi-user detection intensive research.
First the article introduce multiuser detection theory and technology in DS-CDMA systems. Then the most primitive from to the traditional blind adaptive detector testing machines are introduced in the paper. The application and the application prospect of multi-user detection will be introduced in the paper, then the paper will do a specific comparison and analysis for linear blind adaptive multiuser detection algorithm. On this basis, the paper gives an improved prediction based compression approximation subspace tracking algorithm (iPASTd), as well as an improved forecast based on improved approximation algorithm for the compression (iPASTd) and the Kalman filter combining blind adaptive multi-user detector. Simulation results show that given the blind adaptive multiuser detection algorithm based on RLS blind adaptive multiuser detector, and based on LMS algorithm for blind adaptive multiuser detector compared with a good tracking performance, lower complexity, in the AWGN channel to obtain a good signal to interference ratio, and high SNR and strong near-far situation, this paper, blind adaptive multiuser detector can achieve a faster global convergence and good tracking performance.
引文
[1]张平,王卫东,崔春凤等.第三代移动通信系统—WCDMA.北京：北京邮电大学出版社,2000,9-15
[2]胡捍英,杨峰义.第三代移动通信系统.北京：人民邮电出版社,2001,7-12
[3]Tero Ojanpera, Ramjee Prasad.宽带CDMA:第三代移动通信技术.朱旭红,卢学军,卓天真.北京：人民邮电出版社,2001,41-45
[4]Schneider K S.Optimum detection of code division multiplexed signals.IEEE Transaction on Aeros Electron System,1979,15(1):181-185
[5]Verdu S.Minimum probability of error for asynchronous gaussian multiple Acess channels.IEEE Transactions on IT,1986,32(1):85-96
[6]Verdu S.Optimum multiuser asymptotic efficiency.IEEE Transaction on Communication,1986,34(9):890-897
[7]Honig M,Madow U,Verdu S.Blind adaptive multiuser detection.IEEE Transaction on Information Theory,1995,41(4):944-960
[8]Wang X D,Poor H V.Blind multiuser detection:a subspace approach.IEEE Transaction on Information Theory,1998,44(2):677-690
[9]Xiaodong Wang,H Vincent Poor. Space-time multiuser detection in multipath CDMA channels.IEEE Transaction on Signal processing,1999,47(9):2356-2374
[10]Champagne B,Q G Liu.Plane rotation-based EVD updating schemes for efficient subspace tracking.IEEE Transaction on Signal Process,1998,46(7):1886-1900
[11]Papandriopoulos J,Evans J,Dey S.Iterative power control and multiuser detection with outage probability constraints. In:ICC'03. Austrial 2003,2509-2513
[12]Poor H V, Verdu S.Probability of Error in MMSE Multiuser Detection.IEEE Transactions on Information Theory,1997,43(5):858-871
[13]Woodward G, Vucetic B S.Adaptive Detection for DS-CDMA.IEEE Proceedings Communications,1998,86(7):1413-1434
[14]Porat B, Friedlander B.Parametric Techniques for Adaptive Detection of Gaussian Signals.IEEE Transactions on Signal Processing,1994,32(8):780-790
[15]Barbosa A N, Miller S L.Adaptive Detection of DS/CDMA Signals in Fading Channels.IEEE Transactions on Communications,1998,46(1):115-124
[16]Zhang Aiping,Luo Hanwen.Iterative Multiuser Receiver Based on Decorrelating Decision-Feedback Detection.JOURNAL OF SYSTEMS ENGINEERING AND ELECTRONICS,2003,14(1):86-91
[17]Verdu S.Optimum multi-user signal detection:[dissertation]. Urabana Changpaign:Univ.of Illinois,1984,12-16
[18]Li Junqiang,K B Ltaief,Cao Zhigang.A Novel Multiuser Detection Using Group Classification with Smart Antennas for Multi-canrier CDMA Systems.CHINESE JOURNAL OF ELECTRONICS,2003,12(2):208-214
[19]Lupas R, Verdu S.Near-far Resistance of Multiuser Detectors in Asynchronous Channels.IEEE Transactions on Information Theory,1991,37(5):453-465
[20]Poor H V, Verdu S.Probability of Error in MMSE Multiuser Detection.IEEE Transactions on Information Theory,1997,43(5):858-871
[21]Madkour M F,Gupta S C,Wang Y.Sucessive Interference Cancellation Algorithms for Downlink W-CDMA Communications.IEEE Transactions on Wireless Communications,2002,1(1):169-177
[22]Patel P, Holtzman J.Analysis of a Simple Successive Interference Cancellation Scheme in a DS/CDMA System.IEEE Journal on Selected Areas in Communications,1994,12(6):796-807
[23]Patel P,Holtzman J.Performance Comparison of a DS/CDMA System Using a Successive Interference Cancellation (IC) Scheme and a Parallel IC Scheme under Fading Channels. In:ICC 94, SUPERCOMM/ICC'94, Conference Record, Serving Humanity Through Communications. New Orleans,1994,510-514
[24]Xie Z,Short R T, Rushforth C K.A Family of Suboptimum Detectors for Coherent Multi-user Communications.IEEE Journal on Communications, 1990,8(4):683-690
[25]Varanasi M K, Aazhang B.Multistage Detection in Asynchronous Code Division Multiple Access Communications.IEEE Transactions on Communications, 1990,38(4):509-519
[26]Duel-Hallen A.A family of Multiuser Decision-feedback Detectors for Asynchronous Code-division Multiple-access Channels. IEEE Transactions on Communications,1995,43(2):421-434
[27]Behrens R T,Scharf L L.Signal processing applications of oblique projection operators.IEEE Transaction on Signal Processing,1994,42(6):1413-1424
[28]Verdu S.Multiuser detection. Greenwich:JAI Press,1993,369-409
[29]Madhow U,Hoing M.MMSE interference suppression for direct-sequency spread spetrum CDMA.IEEE Transactions on Communications,1994,42(12):3178-3188
[30]冯熳,廖桂生.恒模算法：进展与展望.信号处理,2003,19(5)：441-445
[31]刘胜美,赵春明.基于最小二乘算法及子空间方法的盲多用户检测算法.通信学报,2003,24(5)：29-132
[32]王艺,薛强.多用户检测中盲自适应算法的研究.电讯技术,2000,4(1)：37-40
[33]薛强,吴伟陵.衰落信道中基于CMA的自适应多用户检测算法.北京邮电大学学报,2003,26(1)：78-81
[34]朱小刚,潘理,诸鸿文等.盲恒模多用户检测算法的实现和性能优化.通信技术,2002,35(1)：9-11
[35]Haykin S.Adaptive filter theory.Englewood:Prentice Hall,1996,35-43
[36]Amari S,Cichocki A.Adaptive blind signal processing-Neural network approaches.Procedding of the IEEE,1998,86(10):2026-2048
[37]Yang B.Projection approximation subspace tracking.IEEE Transaction on Signal Process,1995,43(1):95-107
[38]Zhou H,Wo W L,Sharif B S.Subspace based on Blind Adaptive Multiuser Detection Using Kalman Filter.IEE Proceedings Communications,2005,52(3):302-310
[39]Zhang X, Wei W.Blind adaptive multiuser detection based on Kalman filtering.IEEE Transactions on Signal Process,2002,50(1):87-94
[40]Manai N,Ayed R B,Bouallegue R.A Software Simulation Testbed for Multi-user Detection Based on Modified Hopfield Network. In:First International Symposium on Control, Communications and Signal Processing. Hammamet, 2004,335-338
[41]王永刚,焦李成.基于随机Hopfield神经网络的最优多用户检测.电子学报,2004,32(10)：1630-1634
[42]韩靖,郑宝玉.基于Hopfield神经网络的DS-CDMA多用户检测.南京邮电学报,1998,18(2)：1-4
[43]Filippidis,Jain L C,Martin N M.Using Genetic Algorithms and Neural Networks for Surface Land Mine Detection.IEEE Transactions on Signal Processing,1999, 47(1):176-186
[44]Ergun,Hacioglu K. Application of a Genetic Algorithm to Multi-stage Detection in CDMA Systems. IN:Electrotechnical Conference. Mediterranean,1998,846 850
[45]Al-Sawafi M M S,Jervase J A.A Micro-genetic Algorithm-based CDMA Multi-user Detector. In:Second Annual Conference on Communication Networks and Services Research Proceedings. Fredericton,2004,175-180
[46]Papadias C B,Paulraj A.A constant modulus algorithm for multi-user signal separation in presence of delay spread using antenna array.IEEE Signal Processing Lett,1997,1 (4):178-181
[47]张贤达,保铮.通信信号处理.北京：国防工业出版社,2002,200-203
[48]张贤达.现代信号处理.北京：清华大学出版社,2002,246-249
[2]胡捍英,杨峰义.第三代移动通信系统.北京：人民邮电出版社,2001,7-12
[3]Tero Ojanpera, Ramjee Prasad.宽带CDMA:第三代移动通信技术.朱旭红,卢学军,卓天真.北京：人民邮电出版社,2001,41-45
[4]Schneider K S.Optimum detection of code division multiplexed signals.IEEE Transaction on Aeros Electron System,1979,15(1):181-185
[5]Verdu S.Minimum probability of error for asynchronous gaussian multiple Acess channels.IEEE Transactions on IT,1986,32(1):85-96
[6]Verdu S.Optimum multiuser asymptotic efficiency.IEEE Transaction on Communication,1986,34(9):890-897
[7]Honig M,Madow U,Verdu S.Blind adaptive multiuser detection.IEEE Transaction on Information Theory,1995,41(4):944-960
[8]Wang X D,Poor H V.Blind multiuser detection:a subspace approach.IEEE Transaction on Information Theory,1998,44(2):677-690
[9]Xiaodong Wang,H Vincent Poor. Space-time multiuser detection in multipath CDMA channels.IEEE Transaction on Signal processing,1999,47(9):2356-2374
[10]Champagne B,Q G Liu.Plane rotation-based EVD updating schemes for efficient subspace tracking.IEEE Transaction on Signal Process,1998,46(7):1886-1900
[11]Papandriopoulos J,Evans J,Dey S.Iterative power control and multiuser detection with outage probability constraints. In:ICC'03. Austrial 2003,2509-2513
[12]Poor H V, Verdu S.Probability of Error in MMSE Multiuser Detection.IEEE Transactions on Information Theory,1997,43(5):858-871
[13]Woodward G, Vucetic B S.Adaptive Detection for DS-CDMA.IEEE Proceedings Communications,1998,86(7):1413-1434
[14]Porat B, Friedlander B.Parametric Techniques for Adaptive Detection of Gaussian Signals.IEEE Transactions on Signal Processing,1994,32(8):780-790
[15]Barbosa A N, Miller S L.Adaptive Detection of DS/CDMA Signals in Fading Channels.IEEE Transactions on Communications,1998,46(1):115-124
[16]Zhang Aiping,Luo Hanwen.Iterative Multiuser Receiver Based on Decorrelating Decision-Feedback Detection.JOURNAL OF SYSTEMS ENGINEERING AND ELECTRONICS,2003,14(1):86-91
[17]Verdu S.Optimum multi-user signal detection:[dissertation]. Urabana Changpaign:Univ.of Illinois,1984,12-16
[18]Li Junqiang,K B Ltaief,Cao Zhigang.A Novel Multiuser Detection Using Group Classification with Smart Antennas for Multi-canrier CDMA Systems.CHINESE JOURNAL OF ELECTRONICS,2003,12(2):208-214
[19]Lupas R, Verdu S.Near-far Resistance of Multiuser Detectors in Asynchronous Channels.IEEE Transactions on Information Theory,1991,37(5):453-465
[20]Poor H V, Verdu S.Probability of Error in MMSE Multiuser Detection.IEEE Transactions on Information Theory,1997,43(5):858-871
[21]Madkour M F,Gupta S C,Wang Y.Sucessive Interference Cancellation Algorithms for Downlink W-CDMA Communications.IEEE Transactions on Wireless Communications,2002,1(1):169-177
[22]Patel P, Holtzman J.Analysis of a Simple Successive Interference Cancellation Scheme in a DS/CDMA System.IEEE Journal on Selected Areas in Communications,1994,12(6):796-807
[23]Patel P,Holtzman J.Performance Comparison of a DS/CDMA System Using a Successive Interference Cancellation (IC) Scheme and a Parallel IC Scheme under Fading Channels. In:ICC 94, SUPERCOMM/ICC'94, Conference Record, Serving Humanity Through Communications. New Orleans,1994,510-514
[24]Xie Z,Short R T, Rushforth C K.A Family of Suboptimum Detectors for Coherent Multi-user Communications.IEEE Journal on Communications, 1990,8(4):683-690
[25]Varanasi M K, Aazhang B.Multistage Detection in Asynchronous Code Division Multiple Access Communications.IEEE Transactions on Communications, 1990,38(4):509-519
[26]Duel-Hallen A.A family of Multiuser Decision-feedback Detectors for Asynchronous Code-division Multiple-access Channels. IEEE Transactions on Communications,1995,43(2):421-434
[27]Behrens R T,Scharf L L.Signal processing applications of oblique projection operators.IEEE Transaction on Signal Processing,1994,42(6):1413-1424
[28]Verdu S.Multiuser detection. Greenwich:JAI Press,1993,369-409
[29]Madhow U,Hoing M.MMSE interference suppression for direct-sequency spread spetrum CDMA.IEEE Transactions on Communications,1994,42(12):3178-3188
[30]冯熳,廖桂生.恒模算法：进展与展望.信号处理,2003,19(5)：441-445
[31]刘胜美,赵春明.基于最小二乘算法及子空间方法的盲多用户检测算法.通信学报,2003,24(5)：29-132
[32]王艺,薛强.多用户检测中盲自适应算法的研究.电讯技术,2000,4(1)：37-40
[33]薛强,吴伟陵.衰落信道中基于CMA的自适应多用户检测算法.北京邮电大学学报,2003,26(1)：78-81
[34]朱小刚,潘理,诸鸿文等.盲恒模多用户检测算法的实现和性能优化.通信技术,2002,35(1)：9-11
[35]Haykin S.Adaptive filter theory.Englewood:Prentice Hall,1996,35-43
[36]Amari S,Cichocki A.Adaptive blind signal processing-Neural network approaches.Procedding of the IEEE,1998,86(10):2026-2048
[37]Yang B.Projection approximation subspace tracking.IEEE Transaction on Signal Process,1995,43(1):95-107
[38]Zhou H,Wo W L,Sharif B S.Subspace based on Blind Adaptive Multiuser Detection Using Kalman Filter.IEE Proceedings Communications,2005,52(3):302-310
[39]Zhang X, Wei W.Blind adaptive multiuser detection based on Kalman filtering.IEEE Transactions on Signal Process,2002,50(1):87-94
[40]Manai N,Ayed R B,Bouallegue R.A Software Simulation Testbed for Multi-user Detection Based on Modified Hopfield Network. In:First International Symposium on Control, Communications and Signal Processing. Hammamet, 2004,335-338
[41]王永刚,焦李成.基于随机Hopfield神经网络的最优多用户检测.电子学报,2004,32(10)：1630-1634
[42]韩靖,郑宝玉.基于Hopfield神经网络的DS-CDMA多用户检测.南京邮电学报,1998,18(2)：1-4
[43]Filippidis,Jain L C,Martin N M.Using Genetic Algorithms and Neural Networks for Surface Land Mine Detection.IEEE Transactions on Signal Processing,1999, 47(1):176-186
[44]Ergun,Hacioglu K. Application of a Genetic Algorithm to Multi-stage Detection in CDMA Systems. IN:Electrotechnical Conference. Mediterranean,1998,846 850
[45]Al-Sawafi M M S,Jervase J A.A Micro-genetic Algorithm-based CDMA Multi-user Detector. In:Second Annual Conference on Communication Networks and Services Research Proceedings. Fredericton,2004,175-180
[46]Papadias C B,Paulraj A.A constant modulus algorithm for multi-user signal separation in presence of delay spread using antenna array.IEEE Signal Processing Lett,1997,1 (4):178-181
[47]张贤达,保铮.通信信号处理.北京：国防工业出版社,2002,200-203
[48]张贤达.现代信号处理.北京：清华大学出版社,2002,246-249