基于协作多点传输系统的自适应有限反馈

Adaptive Limited Feedback for CoMP System

为了提高协作多点传输系统上行链路的反馈资源利用率,研究了多小区重叠覆盖下的相位反馈问题,并推导出用户自适应反馈比特分配的最优解.用户可根据自身传输信道与干扰信道的信道质量,以及来自不同基站信号之间的相位差信息,自适应地确定相应比特数.通过在预编码中根据反馈的相位差信息进行相位补偿,使得用户端接收信号能够相干叠加.研究表明,该方案在不增加系统反馈开销的条件下,能够较为明显地提高系统吞吐量.

In order to improve the efficiency of feedback resource in the uplink channel,phase feedback in coordinated multiple point（CoMP） systems with multi-cell overlapped was considered and the optimal solution for adaptive limited feedback in users was derived in this paper.The user could decide the allocations of the feedback bits according to the transmission channel gain,the interference channel strength,and the relative phase information of the received signals from different base stations.Besides,pre-adjustment of the phase in pre-coding design at the base stations was employed,which helped to achieve coherent combining of received signals at the user side.Simulation results show that the proposed scheme remarkably improves the system throughput performance without increasing the feedback overhead.