MIMO-OFDM系统Turbo接收机中的信道估计器  

Channel Estimator for Turbo Receiver in MIMO-OFDM Systems

作　　者：胡艳芬[1] 张晓瀛[2] 魏急波[2] 

机构地区：[1]北京邮电大学电信学院,北京100876 [2]国防科技大学电子科学与工程学院,湖南长沙410073

出　　处：《国防科技大学学报》2008年第1期42-46,共5页Journal of National University of Defense Technology

摘　　要：设计了一种新的MIMO-OFDM系统Turbo接收机中的信道估计器。考虑了信道估计误差对编码比特外信息计算的影响,利用软球形译码器的搜索列表和解码器反馈的先验信息对传统EM信道估计中的软信息近似处理进行了修正,获得了更为准确的软符号统计信息用于信道估计,提出了考虑软符号互相关性的Bayesian EM(BEM)信道估计算法。仿真结果表明,新算法较传统EM算法具有更低的误码率和更小的估计均方误差值。A new channel estimator is proposed for Turbo receiver in MIMO-OFDM systems. The channel estimation error was taken into account in the evaluation of the extrinsic information for the coded bits. With the help of the candidates list of the list sphere decoder （LSD） and a prior information from the decoder, the approximation of the soft information in the conventional EM channel estimator was amended, and the statistic information of the soft symbols was improved for channel estimation. A new Bayesian EM channel estimation algorithm, which considers the autocorrelation of the soft symbols, was obtained. The simulation results show that the newly proposed algorithm has better performance in terms of both BER and mean square estimation error in comparison with the conventional EM algorithm.

关 键 词：MIMO-OFDM系统 BEM算法 软球形译码 

分 类 号：TN919[电子电信—通信与信息系统]