OFDM系统中的一种高精度的信道估计算法

在基于OFDM的移动通信系统中，提出一种建立在基于导频的最小二乘（least squares，LS）估计方法基础之上的高精度信道估计方法。该算法首先利用信道时域相关特性，对通过LS算法得到的信道时域冲激响应（Channel Impulse Response, CIR）估计值进行有效径提取，并将所得到的时域估计值变换到频域。然后利用信道频域相关特性，用线性最小均方误差(Linear Minimum Mean Squared Error，LMMSE)合并器对估计结果进行修正。2.4GHz频段上的仿真表明了这种基于导频的信道估计方法能够跟踪信道的时频变化，并且在一定程度上可以接近于理想信道估计的误码率性能。

A Channel Estimation Method of High precision in OFDM System

Based on least square(LS) algorithm,a channel estimation method of high precision in orthogonal frequency division multiplexing(OFDM) system is proposed.Considering the time domain correlation,the estimation value of the time-domain channel impulse response(CIR) is picked up efficiently by using LS algorithm.The time domain results are transformed into frequency domain.And the frequency domain results can be refined through a linear minimum mean square error(LMMSE) combiner according to the frequency domain of each sub-carrier.The simulation results in the frequency band of 2.4 GHz show that the proposed method can track the variance of the channel in both time and frequency domain and achieves a good bit error rate(BER) performance close to the theoretical bound of ideal channel estimation.