预编码和子空间跟踪的OFDM信道盲估计

讨论了一种OFDM信道盲估计方法,首先对进入OFDM系统前的相邻两个OFDM符号进行线性预编码,利用预编码引入的数据结构在接收端构造了一个新的矩阵,使得OFDM频域信道响应成为该矩阵的一维子空间,最后通过自适应子空间跟踪技术实现了信道的盲估计。仿真结果表明该方法能有效地抑制信号分布波动、时变信道及噪声对信道估计的影响,从而有效地降低了OFDM系统的信道估计平均均方误差和无编码码元出错率。

Blind OFDM Channel Estimation Based on Linear Precoding and Subspace Tracking

A new algorithm for blind channel estimation is proposed. A linear precoder is applied on each pair of OFDM symbols before they enter the OFDM systems. Due to the structure introduced by precoding, a new matrix is built to make the channel state information (CSI) be its one-dimension-subspace, and the CSI is estimated by using adaptive subspace tracking techniques. Simulation results demonstrate that the presented method can decreases the influence caused by the varying data distribution, channel, and noise, and can track the variation of channel, therefore, it lowers the mean squared error (MSE) of the channel estimation and the word error rate (WER) of the communication system.