具有用户QoS要求的无小区mMIMO系统最优下行功率分配策略

Optimal Downlink Power Allocation Strategy for Cell FreemMIMO Systems with User QoS Requirements

无小区大规模天线多输入多输出(Multiple-Input Multiple-Output, MIMO)系统采用部署大量的分布式接入点,在相同的时频资源上同时服务所有用户,可以满足用户日益不断增长的高数据速率需求,因此在未来6G中被寄予厚望。针对未来6G中用户的业务流量呈现多样性的特点,可把用户分为两大类:一类为时延敏感用户;另一类为时延容忍用户。考虑了一个在保证时延敏感用户服务质量(Quality of Service, QoS)的前提下,最大化用户最小速率的优化问题,通过优化每个接入点的功率分配系数,求解优化问题得到最优解。通过数值仿真将所提出的优化算法求出的最优功率分配系数与均匀功率分配基准算法求得功率分配系数进行了对比,实验结果表明所提出算法在各种指标下均优于对比基准。

The cell free massive Multiple-Input Multiple-Output(MIMO)system adopts the deployment of a large number of distributed access points,serving all users simultaneously on the same time-frequency resources,which can meet the increasing high data rate needs of users.Therefore,it is expected to be of great importance in the sixth generation wireless communication(6G)in the future.In response to the diversity of user traffic in future 6G,users are divided into two categories:delay sensitive users and delay tolerant users.This paper considers an optimization problem to maximize the minimum user rate under the premise of guaranteeing the Quality of Service(QoS)of delay sensitive users.By optimizing power allocation coefficient of each access point,the optimization problem is solved to obtain optimal solution.Finally,through numerical simulation,the optimal power allocation coefficient obtained by our proposed optimization algorithm is compared with the power allocation coefficient obtained by uniform power distribution benchmark algorithm.Experimental results show that the proposed algorithm is better than the comparison experiment under various indicators.