OFDM系统基于导频的信道估计  

Pilot-based Channel Estimation for OFDM System

作　　者：孟琳君[1] 

机构地区：[1]南京邮电大学光电工程,江苏南京210003

出　　处：《绵阳师范学院学报》2007年第11期28-31,共4页Journal of Mianyang Teachers＇ College

摘　　要：提出了OFDM系统中一种新的基于软信息迭代处理的信道估计算法。该算法将面向判决最小二乘估计算法和盲估计算法相结合,在估计器中构造了一种新的置信度量函数,根据解码和软映射重构的反馈信号置信度大小在两种估计算法中自适应选择,这样估计的信道频响可以有效提高软信息迭代接收性能,大大降低信道估计训练开销。仿真结果表明,该文提出的算法能有效跟踪信道时变,限制传统面向判决估计的错误传播,达到好的系统性能。In this paper,we propose a new channel estimator based on iterative soft information processing. The algorithm combines the decision - directed IS algorithm and the blind estimation algorithm. A new reliability measurement function is constructed in the estimator. Based on the reliability factor of the feedback signal which is reconstructed by the decoder and soft - mapping, an option is made adaptively between two estimation algorithms. The channel response from the estimator can improve the performance of the iterative receiver with soft inform, reduce greatly the training cost for channel estimation. Simulation results show that the proposed algorithm can track the time - varying channel efficiendy, limit the conventional decision - directed estimation＇s errors, and achieve good system performance.

关 键 词：EM算法 BCJR算法 SISO LS(最小二乘算法) 

分 类 号：TN914[电子电信—通信与信息系统]