基于位置分配的去蜂窝massive MIMO系统导频分配功率控制算法

Pilot assignment with power control based on location for cell-free massive MIMO system

针对去蜂窝(cell free,CF)大规模多输入多输出(multiple-input multiple-output,MIMO)系统中存在严重的导频污染问题,提出了一种基于位置分配的贪婪导频分配功率控制算法(greedy pilot assignment based on location with pilot power control,GPABL with PPC).首先,遵循相邻用户不分配相同导频序列的原则进行贪婪导频分配(greedy pilot assignment,GPA);然后,在导频分配的基础上叠加了导频功率控制,选择合理的导频功率控制系数减小信道估计的均方误差.仿真结果表明,将两种方式结合起来进行导频优化,系统的吞吐能力有所提升.

A greedy pilot assignment based on location with pilot power control algorithm(GPABL with PPC)is proposed for the serious pilot contamination problem in the uplink training phase in cell-free(CF)massive multiple-input multiple-output(MIMO)systems.Based on the principle that neighboring users are not assigned the same pilot sequence,the greedy pilot assignment(GPA)is performed.Then,the pilot power control is superimposed on the base of pilot assignment,and a reasonable pilot power control coefficient is chosen to reduce the mean square error of channel estimation.Simulation results show that the joint use of the two pilot optimization strategies can significantly improve the throughput of the system.