毫米波大规模MIMO系统联合稀疏混合预编码优化算法

Optimization algorithm for joint sparse hybrid precoding in millimeter wave massive MIMO systems

为提高毫米波大规模多输入多输出(multiple input multiple output,MIMO)系统频谱效率及误码率性能,提出了一种联合稀疏混合预编码优化算法.首先根据毫米波信道的角度稀疏特性重构波瓣信道,分别对每个波瓣子信道进行混合预编码优化设计;然后针对混合预编码设计中含有非凸约束的多元稀疏信号重建问题,利用数字预编码矩阵的隐含稀疏结构,设计波瓣内每个数据流模拟预编码的自有支撑集和共有支撑集;最后根据模拟预编码矩阵与数字预编码矩阵之间的相关性,联合优化设计模拟预编码和数字预编码矩阵.进行了计算复杂度分析以及仿真分析.结果表明:与OMP算法相比,文中算法计算复杂度降低了91%或93%;相较于SLD算法,文中算法的频谱效率性能提高、误码率性能更好.

To improve the spectral efficiency and bit error ratio performance in the millimeter wave massive multiple input multiple output(MIMO)systems,a hybrid precoding optimization algorithm was proposed based on joint sparsity.According to the sparseness property of the millimeter wave channel in the angular domain,the lobe channel was reconstructed,and the hybrid precoding design was divided into multiple sub-problems for each lobe subchannel.To solve the sparse reconstruction problem with nonconvex constraints,the implicit sparse structure of digital precoding matrix was used to design the self-support set and common support set of analog precoding matrix for each data stream.Based on the correlation between analog precoding matrix and digital precoding matrix,the analog precoder and the digital precoder were jointly optimized.The computation complexity analysis and simulation analysis were completed.The results show that compared with the OMP algorithm,the proposed algorithm exhibits remarkable 91%or 93%reduction in computational complexity with enhancing spectral efficiency and bit error ratio performance when compared to the SLD algorithm.