基于协方差反馈的多天线系统优化发送研究

为了克服多天线信道相关性的影响，提出一种新的自适应发送方案。应用空时分组码特征波束成型技术和格形编码调制（TCM）来获得分集增益和编码增益。针对采用和不采用交织器两种情况，基于成对差错概率（PEP）准则。分析了系统的统计性能，分别得到了使系统编码增益和分集增益最大化的TCM设计准则。根据注水法则和Lagrange乘子法求得波束间功率分配算法最优解。此外，码距作为优化功率加载算法中的权重因子，有效降低了获取波束成形分集的信噪比门限。分析和实验结果表明此方案复杂度低。能有效克服相关衰落。

Optimal Transmission for Multiantenna System with Covariance Feedback

A novel adaptive transmissions system is proposed based on the covariance feedback of multi-antenna correlation channels.Eigen-beamforming(EBF)technique and trellis coded modulation(TCM)concatenated with space time block code(STBC)are used to achieve code gain and diversity gain.The error probability expressions and TCM design criteria are given in two cases with or without interleaving.And the correspondent optimal power allocation(OPA)algorithms are achieved by Lagrange multiplier method,which obey to water-filling principles.Code gain,beamforming diversity and/or build-in-time diversity are obtained respectively.Moreover,the code distance is used as a weight factor in OPA to lower the SNR threshold of achieving beamforming diversity.The results show that the proposed schemes can overcome the correlation fading effectively and have low decode complexity and good performance.