改进的OFDM系统半盲信道估计算法

Improved OFDM Semi-blind Channel Estimation Algorithm

信道估计算法从先验信息的角度,可分为3类:基于参考信号的估计、盲估计和半盲估计。半盲估计是结合盲估计与基于训练序列估计这2种方法优点的信道估计算法。本文首先通过基于导频辅助的半盲信道算法和基于直接判决的半盲信道算法得出信道的估计值,再定义一个置信度函数得出加权系数γ,使基于导频辅助的半盲信道算法和基于直接判决估计算法有效结合起来,有效提高信道估计的精度。

Channel estimation algorithm can be divided into three categories for priori information：the estimation based on refer-ence signal, blind estimation and semi-blind estimation.Semi-blind estimation is a channel estimation algorithm combined with the advantages of the blind estimation and channel estimation method and the estimation method based on training sequence .This paper obtains the channel estimation value through semi-blind channel estimation algorithm based on pilot assisted and semi-blind channel estimation algorithm based on direct judgment , then defines a confidence function to obtain the weighted coefficient γ, combines the semi-blind channel algorithm based on pilot assisted and the estimation algorithm based on direct judgment to effec -tively improve the accuracy of channel estimation .