叠加训练序列OFDM系统的一种迭代信道估计方法  

A Method of Iterative Channel Estimation for OFDM Using Superimposed Training Sequence

作　　者：周键[1] 唐友喜[1] 刘皓[1] 黄川[1] 

机构地区：[1]电子科技大学通信抗干扰技术国家级重点实验室,四川成都610054

出　　处：《电子学报》2007年第B06期165-168,共4页Acta Electronica Sinica

基　　金：国家自然科学基金(No.60572090;60472045;60496313);教育部博士点基金(No.20050614009)

摘　　要：在瑞利多径衰落信道中,针对叠加训练序列正交频分复用系统的迭代接收机,提出了一种迭代信道估计方法.在迭代译码开始前,利用与数据符号同时发送的训序列得到信道估计初始值,并在每次迭代后利用更新的码字比特先验信息估计接收信号中的数据符号,计算更准确的信道估计值.理论分析给出了每次迭代后的信道估计值的均方误差性能.在多径衰落信道中,通过计算机仿真验证了该迭代信道估计方法的有效性和可靠性.A method of iterative channel estimation is proposed for orthogonal frequency division multiplexing （OFDM） system using superimposed training sequence with iterative receiver. The training sequence is exploited to get an initial channel estimate such that the iterative decoding process can be started. After each decoding iteration, the updated log likelihood ratio （LLR） of a posteriod probabilities on the coded bits are used to estimate the transmitted data symbols, which are fed back and used to improve channel estimates. Theoretical analysis of the mean square error （MSE） of the channel estimates is presented. In frequency selective fading channel, computer simulations of MSE performance of the channel estimation method and bit error rate （BER） performance of the system under different conditions are given, which demonstrate the efficiency and validity of the proposed method.

关 键 词：信道估计 正交频分复用 迭代检测 叠加训练序列 

分 类 号：TN929.5[电子电信—通信与信息系统]