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.
出处
《电子学报》
EI
CAS
CSCD
北大核心
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)
关键词
信道估计
正交频分复用
迭代检测
叠加训练序列
channel estimation, orthogonal frequency division multiplexing, iterative detection, superimposed training sequence
