OFDM（正交频分复用）系统以其抗多径衰落和较高的频带利用率，得到了众多领域的广泛应用。本文就OFDM系统中关键技术之一的信道估计技术进行了介绍。并分别叙述了OFDM系统和信道估计的意义，归纳了信道估计的分类，最后介绍了MMSE、LS及其改进信道估计算法并仿真出结果。-OFDM（orthogonal frequency division multiplexing) has been widely used in many areas for its good resistance to multipath fading and high bandwidth efficiency.In this paper,channel estimation,which is one of the key technologies in OFDM systems,were introduced.

Then we discuss the significance of the channel estimation and the classification of channel estimation.Finally,we study the algorithms of channel estimation such as MMSE,LS and LMMSE,and further get the simulation results.