一种低复杂度的下行MIMO多用户分组策略

A low complexity grouping strategy for downlink of multi-user MIMO channels

在研究了多用户 MIMO 线性处理技术和多用户选择方法的基础上,提出了多用户分组的思想。为了降低分组过程的复杂度,提出了基于最小奇异值和信道向量的内积的分组评价准则,并且给出了一种低复杂度的快速分组算法。仿真结果显示所提出的算法可以明显提升系统性能:随着系统中激活用户数量的增加,逐渐接近单用户点对点 MI-MO 通信系统的性能;在一个具有4个发射天线的基站的系统中,当发射信噪比达到15dB,分组数量达到10时,采用了快速分组策略后,块对角化和规格化反转方法的各态历经性信道容量分别提升4bits/Hz 和3bits/Hz 以上。

The paper presents the concept of multi-user grouping based on the study of linear preprocess methods and user selection methods for downlink of multi-user MIMO channels, and to reduce the complexity of grouping procedure, provides simplified grouping criteria based on minimal singular value and inner products of channel vectors, and provides a fast grouping algorithm with low complexity. The simulation results show that the algorithm can improve the system performance： with increase of quantity of active users, sum capacity of the system using proposed algorithm is close to that of point to point MIMO systems for single user; a four antenna system with the transmit SNR（signal to noise ratio） of 15dB and the grouping quantity of 10 can promote the sum capacity of block diagonalization and that of regular channel inversion by more than 4bits/Hz and 3bits/Hz respectively if using the proposed algorithm.