MIMO多中继系统中基于不完全信道状态信息的预编码算法研究

摘要

针对配置多个中继节点的多输入多输出(Multiple-input Multiple-Output,MIMO)系统,提出一种不完全信道状态信息(Imperfect channel state information,CSI)下基于最小均方误差(Minimum Mean-Squared Error,MMSE)准则的预编码设计方案,该方案综合考虑各个节点天线之间的相关性及信道估计误差.由于各个中继端预编码矩阵之间可视为相互独立,故将约束优化问题转化为若干半正定规划问题,继而通过内点法或CVX工具箱求解预编码矩阵,然后采用求导法推导出接收端处理矩阵.最后利用迭代算法交替迭代来联合优化预编码矩阵和接收端处理矩阵,直到算法收敛.仿真结果表明,与未能综合考虑各个节点的预编码算法相比,本文提出的算法能明显改善系统BER性能.%A robust transceiver design for MIMO multi-relay system is proposed.Imperfect channel state information (CSI)is considered,the antenna correlation at both ends of the channel and the channel estimation errors are taken into account.Since the precoding matrix of each relay is independent of each other,subsequently the original problem can be decoupled into several semi-definite programming problem (SDP) problems,then the source precoding matrix and the relaying matrix are optimized by the interior-point method or CVX toolbox,the equalizer is optimized by a direct derivation method and an alternating algorithm is proposed for the joint design.Simulation results shows that the proposed design approach achieves better BER performance than other approaches.