基于最大似然序列估计的MSDD OFDM载波间干扰抑制法

摘要

为抑制多符号差分检测(MSDD)OFDM系统中的载波间干扰(ICI),分析了载波间干扰的统计性影响,并在最大似然序列估计过程中考虑了这些影响.提出了通过在最大似然序列估计过程中利用全部子载波信号的信息估计并抑制载波间干扰的方法.为降低计算复杂度,进一步提出了几种利用部分子载波信号信息的次优载波间干扰抑制法.仿真结果表明:所提出的次优方法在平坦及频率选择性瑞利信道中均可显著提高误码率性能.%To suppress the intercarrier interference(ICI)in multiple-symbol differential detection(MSDD)orthogonal frequency division multiplexing(OFDM)systems,statistical effects of ICI are analysed and then considered in the maximum likelihood sequence estimation(MLSE)process.Afterwards,a method,which can estimate and suppress the ICI by utilizing the knowledge of all the subcarriers in the MLSE process,is proposed.To　reduce the computational complexity,several suboptimal ICI suppression methods,which utilize the knowledge　of part of the subcarriers,are further proposed.Simulation results show that the proposed suboptimal methods can significantly enhance the bit error rate(BER)performances in both flat and frequency selective Rayleigh fading channels.