毫米波MIMO系统离散化混合预编码设计

Discrete hybrid precoding design for millimeter wave MIMO systems

为了提高毫米波大规模多输入多输出(MIMO)系统波束成形增益,降低天线与移相器的硬件成本,提出一种基于离散移相器的混合预编码设计方案。以最优化频谱效率为目标,该方案通过分析均匀直线阵列与均匀平面阵列的响应矢量,将毫米波信道的空间特性预编码的设计考虑为空间稀疏重构问题,采用离散化正交匹配追踪原理求出数字预编码与离散化的模拟预编码。仿真结果表明,同等条件下平面阵列的频谱效率优于直线阵列,同时所提出的离散化混合预编码方案中低精度移相器的性能近乎达到全精度移相器的性能增益。

In order to improve the beamforming gain of millimeter-wave massive MIMO system and reduce the hardware cost of antenna and phase shifter,this paper proposed a hybrid precoding design scheme based on discrete phase shifter. Aiming at optimizing spectral efficiency of the system,this scheme considered the spatial characteristic precoding design of millimeter wave channel as spatial sparse reconstruction problem according to the response of uniform linear array and uniform planar array,which used discretized orthogonal matching tracking principle to obtain the digital precoding and discretization of analog precoding. The simulation results show that the spectral efficiency of the planar array is better than that of the linear array under the same conditions. At the same time,the performance of the low-precision phase shifter in the proposed discretization hybrid precoding scheme almost reaches the performance gain of the full-precision phase shifter.