V-BLAST OFDM中的载波间干扰分析

Analysis of Intercarrier Interference in V-BLAST OFDM

从理论上分析了垂直贝尔实验室分层空时结构(V-BLAST)正交频分复用(OFDM)系统中,由于无线移动信道的时变性引入的多普勒(Doppler)扩展所导致的载波间干扰(ICI).推导了瑞利(Rayleigh)平坦衰落信道下ICI功率的理论结果,并用平均矢量误符号率(AVSER)分析了存在ICI时系统在最大似然(ML)检测下的理论性能.分析结果表明,由多普勒扩展导致的ICI会使系统产生较为严重的性能平层;利用多个接收天线所提供的空间分集可在一定程度上抑制ICI,从而改善系统性能.

The intercarrier interference （ICI） in vertical Bell Labs layered space-time （V-BLAST） orthogo- nal frequency division multiplexing （OFDM） systems was theoretically analyzed, which was caused by the Doppler spread due to time variations of the wireless mobile channel. The theoretic result of the ICI power in Rayleigh flat-fading channels was derived and theoretical performance of the system was analyzed by average vector symbol error rate （AVSER） under the maximum likelihood （ML） detection when ICI existed. The results show that the ICI leads to a significant error floor in system performance and that the spatial di- versity formed by using multiple receiving antennas can resist the ICI to some extent, which will improve the system performance.