针对大气激光通信下的OFDM(正交频分复用)系统，对几种基于导频的信道估计方法进行了比较分析，并给出了仿真结果。仿真结果表明，SVD-LMMSE(基于奇异值分解的线性最小均方误差)算法在提高信道估计精度的同时，可以降低系统计算的复杂度；增大CP(循环前缀)可以非常有效地提高系统性能。

In this paper, several pilot-aided channel estimation methods are compared and analyzed for Orthogonal Frequency Division Multiplexing (OFDM) systems in atmospheric laser communications. The simulation results show that while improving the channel estimation accuracy, the Singular Value Decomposition-Linear Minimum Mean Square Error (SVD-LMMSE) algorithm reduces the complexity of the system computations and the increase of the Cyclic Prefix (CP) effectively improves the system performances.