基于傅立叶变换的OFDM信道估计方法研究

DFT based channel estimation methods for OFDM

分析了无线OFDM系统中基于傅立叶变换的信道估计方法,提出了在低信噪比情况下使用LMMSE估计的一种改进方法和在高信噪比情况下使用不需要先验信息的LS估计的改进方法。仿真结果表明,在无线多径慢衰落信道条件下,该改进方法都能够有效对抗频率选择性和先验信息的估计偏差对信道估计的影响,在估计性能与算法复杂度之间取得良好折衷。

The DFT based channel estimation algorithms in orthogonal frequency division multiplexing （OFDM） systems is analyzed, and two modified DFT-based methods are proposed to estimate the frequency selective wireless channel.. One method used the modified minimum mean square channel estimation method or a modified least square estimation method at low SNR, and the other used the modified least square channel estimation method without prior information at high SNR. The simulation results show that the proposed methods can withstand the frequency selectivity at slow fading wireless channel and the estimation error of prior information needed in receiver, and the modified methods behave favourably at both channel estimation performance and computation complexity.