WPT-CDMA系统中的鲁棒自适应波束形成算法的研究  

Robust Adaptive Beamforming Algorithm in WPT-CDMA System

作　　者：李建林[1] 刘梅[1] 张君威[1] 丁力[1] 杨莹[1] 

机构地区：[1]哈尔滨工业大学电子与信息技术研究院,黑龙江哈尔滨150001

出　　处：《通信技术》2009年第4期1-3,共3页Communications Technology

基　　金：哈尔滨市科技攻关计划项目支持(编号:2006AA1CG102)

摘　　要：利用小波包变换的多载波调制避免了OFDM技术中由多径效应引起的载波的正交性损失,同时降低了为此加入的循环前缀引起的信噪比损失,因而使用小波包变换的多载波CDMA系统(WPT-CDMA)性能优于传统的OFDM-CDMA系统。但在MIMO多用户传输环境下,接收机端的约束最小均方(CLMS)自适应波束形成算法在信号方向向量存在偏差及采样样本数目较少的情况下,会出现收敛速度慢、输出性能下降、不稳定等问题。针对这些问题本文提出应用在WPT-CDMA系统中的基于最差性能的鲁棒CLMS算法。从理论分析与仿真实验的结果都可以看到系统性能的改善。The multi-carrier modulation with wavelet packet resolves the orthogonality damage in OFDM modulation caused by multi path effect while decreases the SNR loss caused by cyclic prefix. Thus multi-carrier CDMA system using wavelet packet transformation （WPT-CDMA） has higher performance than OFDM-CDMA system. In the MIMO multi-user transmission condition, however, there are some flaws for constrained linear minimum square （CLMS） adaptive beamforming algorithm in WPT-CDMAsystem, e.g. the convergence is slower, the output performance worsens and the instability appears due to deviation from direction vector of received signal and limited samples. Therefore, a robust CLMS adaptive beamforming algorithm applied to WPT-CDMA system based on worst performance is proposed：. thus to address these problems. Theoretical analysis and simulation results indicate that the system performance is significantly improved.

关 键 词：鲁棒CLMS算法 MIMO WPT—CDMA 

分 类 号：TN911[电子电信—通信与信息系统]