不同信道条件下MIMO空时编码技术的特性分析

摘要

为了分析多输入多输出（ MIMO）空时编码技术在不同信道条件下的性能优劣，研究了无线信道的衰落统计特性，对比了在Rayleigh信道、Rician信道和Nakagami信道条件下，正交频分复用空时块编码（ STBC-OFDM）、垂直空时分层码（ V-BLAST）及空时格型码（ STTC）的系统误码率。通过仿真分析结果表明：STBC-OFDM系统在衰减指数为5的Nakagami信道条件，系统误码率最低，Rician信道次之，Rayleigh信道最高，而且当系统误码率为10－3时，其所需的信噪比（ SNR）分别为7，9，11 dB；但对于V-BLAST和STTC系统，随着信噪比的增加，不同的信道条件对系统误码率的影响各有优劣。%To analyze performance advantages and disadvantages of multi-input multi-output( MIMO)space-time coding technique in different channel conditions,study fading statistics characteristics radio channel,compare system bit error rate(BER)of orthogonal frequency division multiplexing space-time block coding(STBC-OFDM),vertically layered space-time code( V-BLAST)and space-time trellis code( STTC)in the Rayleigh channel,Rician channel and Nakagami channel. Simulation analysis results show that STBC-OFDM system in Nakagami channel conditions whoses decay index is 5,BER is the lowest,Rician channel followed,Rayleigh channel is the highest,and when BER of system is 0. 001,its required SNR is 7,9,11 dB;and for V-BLAST and STTC systems,with signal noise ratio( SNR)increasing,effects of different conditions of channel on BER of system are advantages and disadvantages.