基于WR分解的多用户多天线OFDM系统半盲信道估计  

A Whitening-rotation-based Semi-blind Channel Estimation Method for Multiuser Multiantenna OFDM System

作　　者：高月幸[1] 杨杰[1] 朱卫平[1] 孟庆民[1] 

机构地区：[1]南京邮电大学信号处理与传输研究院,江苏南京210003

出　　处：《南京邮电大学学报（自然科学版）》2012年第3期16-20,共5页Journal of Nanjing University of Posts and Telecommunications：Natural Science Edition

基　　金：国家自然科学基金(60872104);江苏省高校自然科学基金(08KJD510001);教育部博士基金(20080293004)资助项目

摘　　要：在多用户多天线OFDM上行信道的模型下,提出一种改进的基于WR分解的半盲信道估计算法。改进算法利用接收信号的统计特性和子空间分解法直接估计白化矩阵W,避免了对导频信号的依赖和模糊矩阵的求解问题。在已知W矩阵后,根据正交导频的设计方案,由最小均方误差准则得到Q矩阵。计算机仿真结果表明,系统的信道冲击响应可以被很好的跟踪,且当信噪比达到20 dB时,改进算法的RMSE比LS算法降低约1～1.5 dB。与此同时,正交导频的长度对于改进算法的性能具有较大的影响,当导频信号的长度达到整个OFDM符号块长度的1/5时,改进算法的RMSE比LS算法降低约1～2 dB。A novel semi-blind channel estimation method, which is based on WR decomposition, is proposed under the model of multiuser and muhiantenna OFDM uplink system. In this algorithm, whitening matrix W is estimated directly by the statistical of received signals and the subspace decomposition algo- rithm without the aid of pilot signals and the computing of the ambiguity matrix. With the knowledge of matrix W and orthogonal pilots, matrix Q can be estimated quickly through the least mean square criteri- on. Simulation results show that channel responses of the uplink channels can be traced well. Compared with LS algorithm, when SNR approaches 20 dB, RMSE can be reduced by 1 - 1.5 dB. At the same time, when the length approaches 1/5 of the whole OFDM block, RMSE can be reduced by 1 -2 dB.

关 键 词：多用户多天线 半盲信道估计 WR分解 子空间分解法 归一化最小均方误差 

分 类 号：TN929.5[电子电信—通信与信息系统]