Abstract: This paper analyses common methods of channel estimating under the wireless environment with multipath and noise.And a novel two-dimensional pilot pattern is proposed which fully keeps the channel information，by which we can get the optimal initial estimation result of channel parameter.Based on the proposed method，DFT/IDFT transform is employed to separate the sub-spaces of noise and channel frequency response.Analysis and simulation results show that the novel channel estimation algorithm of this paper improves the estimate performances remarkably.

Key words: OFDM, channel estimation, pilot settings, transform-domain, noise-reducing filter

摘要： 在分析多径噪声环境中信道估计经典算法的基础上，提出一种基于二维导频和降噪滤波的信道估计改进算法。文中采用的二维导频设置图案，充分保留了信道信息，从中可提取信道参数的最优初始估计。在此基础上，通过DFT/IDFT变换将信道频率响应子空间和噪声子空间分离，进行降噪滤波。仿真结果显示，在多径时变衰落信道下，利用以上两种提出的信道估计方法有效提高系统的估计性能。

关键词: 正交频分复用, 信道估计, 导频设置, 变换域, 降噪滤波