OFDM(正交频率调制)实现多载波调制基本思想是将带宽信道分解成许多并行的窄子信道，是每个子信道的想干带宽，从而实现平稳衰落。搭建了完整的OFDM信道链路系统，运用三种不同的信道估计方法(LS信道估计、DFT信道估计、Improved-DFT信道估计)，并对AWGN理想信道和衰落信道误码情况进行了仿真和比较。-OFDM (Orthogonal Frequency Modulation) multicarrier modulation basic idea bandwidth channel is decomposed into a number of parallel narrow subchannels, each subchannel wanted bandwidth, in order to achieve a smooth fading. Build a complete OFDM channel link system, the use of three kinds of different channel estimated method (LS channel estimated, to the DFT letter Tao estimates, Improved-the DFT letter Road estimated), and AWGN ideal letter Road and fading channel bit error situation conducted a simulation and comparison .