稀疏信道下OFDM信号的迭代检测方法

Iterative detection of OFDM signals in sparse channel

提出了一种适用于稀疏信道环境的OFDM信号迭代检测方法。该方法采用导频进行初始化信道估计,使用数学期望最大(EM)算法迭代检测OFDM信号。该方法需要已知信道的路径时延信息、噪声方差和信道冲击响应的协方差矩阵,因此同时给出了这些参数的估计方法。仿真结果证明了这种迭代算法的有效性,而且使用估计的信道参数时的系统性能和理想参数条件下的性能接近。

An iterative detection of OFDM signals for sparse channel is proposed in this paper.Pilot based channel estimation is used as the initialization of the detection.Expectation Maximization algorithm is then used to detect OFDM signals iteratively.The path delay information, noise power and the covariance matrix of the channel response are needed in this method,so the methods of estimating all these channel parameters are also given.The simulation results prove the efficiency of the iterative algorithm,and also prove that by using the estimation parameters of the channel,the performance can nearly approximate the perfect channel state information.