STC-OFDM系统中的信道估计算法

针对稀疏信道特性的STC-OFDM系统，提出一种基于参数模型的导频信道估计方法。利用最小二乘算法估计出导频所在位置的频率响应，用时间平均相关代替统计平均相关，得到信道相关矩阵的估计值。通过基于特征值分解的低秩建模，估计出信道的多径数目，利用旋转不变子空间方法估计出各个延迟的时间参数，在频率和时间域上插值平滑得到信道的频率响应。该方法不需要已知信道的先验信息，仿真结果证明了该方法的有效性。

Channel Estimation Algorithm in STC-OFDM Systems

A channel estimation method based on parametric channel model using pilots in STC-OFDM systems is proposed here. The channel frequency response of the pilots is firstly estimated using LS algorithm, and then the correlation matrix of the channel is estimated by using the time-average channel correlation matrix in place of the statistical correlation matrix. The number of the multi-path is estimated by low rank Eigen-value decomposition and the time delay is estimated by using Estimation of Signal Parameters via Rotational Invariance Techniques(ESPRIT). The entire channel frequency response is interpolated in time and frequency domain. The method need not know the prior information of channel, and the simulation results show the efficiency of the proposed method.