MIMO-OFDM系统的一种新的半盲估计  

A Noval Semi-blind Channel Estimation for MIMO-OFDM Systems

作　　者：胡峰[1] 李建平[1] 刘瑞奇[2] 

机构地区：[1]中国传媒大学,北京100024 [2]电子科技大学,成都610054

出　　处：《中国传媒大学学报（自然科学版）》2010年第2期36-40,35,共6页Journal of Communication University of China：Science and Technology

基　　金：教育部留学归国人员科研启动基金项目(2007[24]);教育部科学技术重点项目(106042)

摘　　要：构造一种在MIMO-OFDM系统下的信道估计算法,该算法是将信道矩阵分解为一个下三角矩阵R和一个酉矩阵Q的估计过程,由此命名为RQ估计。R矩阵可以通过提取接收信号的相关信息盲估计得到,而Q矩阵需要应用Cholesky分解和OPML技术从训练序列中专门估计出来。采用酉矩阵的算法参量化后的待估参数明显减少,信道估计的精度因此得到了极大地改善。另外,这种估计算法在接收天线数目大于或等于发射天线的时候,优势更为明显。实验结果表明,基于Q矩阵的估计比直接的训练序列信道估计算法更为高效;在瑞利衰落信道条件下处理200个训练序列时,两者的性能差距能达到4dB。This paper proposes a channel estimation algorithm for multiple-input and multiple-output orthogonal frequency division multiplexing（MIMO-OFDM） systems.The algorithm named RQ estimator is based on decomposition of channel matrix H as a down-trigonal matrix R and a unitary rotation matrix Q.The matrix R is estimated blindly by using only received data while the optimum rotation matrix Q is estimated exclusively from training samples based on Cholesky decomposition and OPML（Orthogonal Pilot ML Estimator） techniques.Significant estimation gains can be achieved by estimation of such optimum rotation matrices which are parameterized a fewer number of parameters.This semi-blind scheme is shown to be very efficient when the number of receive antennas is greater than or equal to the number of transmit antennas.Simulation results confirm that the presented estimation based on estimating only the Q matrix from training sequences can perform more efficiently than estimating H directly from the pilot data,and an additional about 4 dB in performance gain would result when adopting 200 PN sequence over Rayleigh fading channels.

关 键 词：CHOLESKY分解 MIMO-OFDM OPML算法 QR分解 半盲信道估计 

分 类 号：TN92[电子电信—通信与信息系统]