本文首先介绍了两种协作方式与OFDM框架，并结合OFDM技术进行了系统仿真，对比分析了OFDM系统与CRC编码OFDM系统与卷积码编码OFDM系统仿真性能。-two methods to realize cooperative diversity in OFDM systems are proposed simulations using OFDM techniques are performed and the performance of the CRC coding OFDM syst