DS-CDMA水声通信多用户检测空时自适应均衡算法  

Adaptive Multiuser Detection Space-Time Equalization Algorithms for DS-CDMA Underwater Communication System

作　　者：韩晶[1] 黄建国[1] 何成兵[1] 

机构地区：[1]西北工业大学航海学院,陕西西安710072

出　　处：《西北工业大学学报》2010年第3期398-403,共6页Journal of Northwestern Polytechnical University

基　　金：中国博士后科学基金(20080441183)资助

摘　　要：在具有扩展多径与快速时变特性的水声信道环境中,文章对采用直接序列码分多址的多用户网络水声通信进行研究。提出了2种自适应均衡算法:串行干扰抵消符号判决反馈空时二维均衡(SIC-ST-SDFE)算法与串行干扰抵消码片假设反馈空时二维均衡(SIC-ST-CHFE)算法。两算法分别基于符号速率与码片速率更新均衡器系数,同时通过交叉反馈滤波器实现SIC多用户检测。仿真与湖上实验结果显示,DS-CDMA系统采用上述算法,具有较传统非中心化空时均衡算法更强的MAI抑制能力,其中SIC-ST-CHFE以增加计算复杂度为代价,可获得更强的信道时变跟踪能力。提出的算法在5 km浅水信道、两用户配置且接收信噪比分别为0 dB与7 dB的实验条件下实现了信息的可靠接收检测。Our aim is to suppress the multi-access interference （MAI）. We propose two new algorithms： SIC-ST- SDFE and SIC-ST-CHFE, where SIC is successive interference cancellation, ST is space-time, FE is feedback equalization, SD is symbol decision, CH is chip hypothesis. Section 1 of the full paper briefs the DS-CDMA （ directsequence code division multiple access） system model. Section 2 briefs the optimal space time multiuser receiver. Section 3 explains our two new algorithms; its core consists of： （1） that the two algorithms update the coefficients of the receiver＇ s equalizer at symbol rate and chip rate respectively and implement the SIC multiuser detection by using cress-over feedback filters; （2） that we give Figs. 2 and 3 to show their architectures. In section 4, we simulated the algorithms and did lake tests; the simulation results and test results, presented in Figs. 4 （a） through 4 （ f）, and their analysis show preliminarily that： （ 1 ） both our algorithms have better capability of suppressing MAI than the conventional decentralized space-time equalizer; besides this, the SIC-ST-CHFE algorithm has a better time-variability tracking performance, although its computational complexity increases; （2） under the test conditions that the communication channel is over 5 km and that two users have the SNR approximately 0 dB and 7 dB respectively, both our new algorithms can achieve reliable information transmission.

关 键 词：水声通信 码分多址 空时处理 多用户检测 假设反馈均衡 串行干扰抵消 

分 类 号：TN929.3[电子电信—通信与信息系统]