采用均衡技术的OFDM系统性能分析

Performance Analysis of OFDM System with Equalization Technology

当发送信号通过带限的、非理想信道时 ,通常会产生码间串扰 (ISI) ,采用均衡技术可以有效的进行补偿。介绍了正交频分复用 (OFDM)系统中的两种均衡技术 (基于导频平均的均衡和最小均方算法的均衡 )的特点和实现方法 ,以多谱勒频移为主要信道参数 ,对瑞利衰落信道条件下的 OFDM系统分别采用两种均衡时的性能进行了分析和比较。仿真分析结果表明 ,对于变化较快的信道 ,采用导频平均均衡 ,而 LMS均衡算法只适用于变化较慢的信道。

The equalization technology can be used to compensate for the ISI which occurs when the transimitted signal passes through the band limited and non ideal channel. This paper makes a brief introduction to the features and implementing methods of the two kinds of equalization technology (based on the equalization of pilot average and LMS algorithm) adopted in OFDM system; using the Doppler spread as the main channel reference, the paper analyzes and compares the performance of OFDM system when it adopts respectively the two kinds of equalization in the Rayleigh fading channel. The simulation shows that for the rapidly changing channel pilot average should be used, while LMS algorithm is only suitable to the slowly changing channel.