有限反馈MIMO系统下行链路用户调度与功率分配

研究基于有限反馈的下行MIMO系统中的用户调度和功率分配问题,并利用随机多波束形成的思想提出了相应的实现算法.所提出的用户调度算法只将各用户的最大和第2最大信干噪比及其对应的波束索引号反馈给基站,仿真结果表明,与现有方法相比,该算法更好地获得了所需反馈量和系统吞吐量之间的折衷.所提出的功率分配算法则充分利用了基站端所能获得的部分信道信息,仿真结果表明,与传统的平均分配算法相比,在发射总功率一定的情况下,该算法可以获得更高的系统吞吐量.将两种算法相互结合,可以在不增加反馈量的情况下获得更好的系统性能.

User Scheduling and Power Allocation for Downlink of MIMO Systems with Limited Feedback

User scheduling and power allocation are investigated for the downlink of MIMO systems with limited feedback.Corresponding algorithms are proposed based on the idea of opportunistic multiple beamforming.The proposed algorithm feeds the first and the second maximum SINRs of each user and indices of the corresponding beamforming back to the base station only.Simulations show that,compared with previous methods,it can better acquire tradeoff between feedback overhead and total throughput.The proposed power allocation algorithm makes full use of the partial channel state information.Numerical results show that this method can obtain higher throughput under the constraint of available transmit power compared to conventional methods.When the proposed user scheduling and power allocation algorithms are combined,better performance can be obtained without increasing feedback overhead.