多天线系统及其在OFDM系统中的应用

利用配置多个天线实现高速可靠的通信是当今无线通信领域研究的热点之一。本文介绍了具有多个天线系统的几种不同构成方式，从系统误码率和频带利用率两个方面讨论了不同构成方式对系统的改善。同时，对多天线技术应用于正交频分复用(OFDM)系统的性能进行了分析，并给出了频率选择性瑞利衰落信道中最优译码算法下的系统性能比较。仿真结果表明，多天线OFDM系统既保持了OFDM抗频率选择性衰落的特点，又能够改善系统的误码率性能，提高频带利用率。

Multiple Antennas System and Its OFDM Application

One highlight of current wireless communication area is to use multiple antennas to achieve high speed and robust transmission. This paper describes several system structures with multiple antennas and analyzes their performances from the viewpoint of bit error rate and bandwidth efficiency . Furthermore,the systems combined with OFDM technique are also analyzed, and simulation results in frequency-selective channel are given. The results show that such combination keeps the combating ISI advantage of OFDM technique, and also take the diversity advantage of multiple antennas to improve the system capacity, either in BER or/and bandwidth efficiency.