Abstract: MIMO（Multiple-Input Multiple-Output） system can improve spectrum efficiency effectively, and does not need to increase the bandwidth of the system. However, the existing pre-coding method and number of antenna make the accommodated users is a finite number, and can not meet the practical needs. To solve this problem, this paper presents a user selection algorithm with equal power allocation. The proposed algorithm gets the optimum user groups by the equivalent approximation of channel capacity. At the same time, in order to reduce the complexity of the user selection algorithm further, an iterative suboptimal user selection algorithm is proposed to select the optimum users fastly. The simulation results show that the algorithm can obtain better performance of the system capacity, and is suitable for the actual communication system.

Key words: Multi-user MIMO system, user selection, iteration

摘要： MIMO系统在不增加带宽的情况下可以有效提高频谱效率。但由于多用户MIMO系统现存预编码方法和系统天线数目的限制，使得系统容纳用户数为一限定值，无法满足实际需要。针对这一问题，给出一种等功率分配的用户选择算法，其通过对信道容量等效近似来得到较优的用户组。为了降低用户选择复杂度，给出一种迭代的次优用户选择算法，达到快速选取较优用户的目的。仿真结果表明所提算法可以获得较好的系统容量性能，适用于实际通信系统。

关键词: 多用户MIMO系统, 用户选择, 迭代