基于不完全信道状态信息的多用户MIMO中继系统预编码算法  

Linear Precoding Algorithm for Multi?user MIMO Relay System with Imperfect Channel State Information

作　　者：陈小敏[1,2] 方竹 胡续俊 朱秋明 陈兵[2] Chen Xiaomin;Fang Zhu;Hu Xujun;Zhu Qiuming;Chen Bing(College of Electronic and Information Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing,211106,China;Jiangsu Key Laboratory of Internet of Things and Control Technologies,Nanjing University of Aeronautics and Astronautics,Nanjing,211106,China)

机构地区：[1]南京航空航天大学电子信息工程学院,南京211106 [2]南京航空航天大学江苏省物联网与控制技术重点实验室,南京211106

出　　处：《数据采集与处理》2019年第2期252-261,共10页Journal of Data Acquisition and Processing

基　　金：中央高校基本科研业务费专项资金(NS2016044;NS2015046)资助项目;江苏省博士后基金(1601017C)资助项目;江苏省普通高校专业学位研究生科研创新计划(SJLX16_0111)资助项目;南京航空航天大学研究生创新基地(实验室)开放基金(kfjj20160412)资助项目

摘　　要：针对上行多用户MIMO中继系统,在信道存在反馈延迟及估计误差的条件下,以误比特率(Bit error rate,BER)为优化目标,提出了基于最小均方误差(Minimum mean?squared error,MMSE)准则的预编码算法。所提算法将求解发射端、中继节点、接收端矩阵的复杂非凸问题分解为3个独立的子优化问题,发射端的用户配备单天线且服从空间独立分布,先确定发射端预编码矩阵,将求解中继矩阵的凸优化问题转化为半正定规划(Semi?definite programming,SDP)问题,采用CVX工具箱求解,接收端处理矩阵通过线性搜索法求解,最后采用联合迭代法得到各节点矩阵的最优解。仿真结果表明,所提算法能有效改善系统的误比特率性能。For up-link multi-user multiple-input multiple-output relay systems,with the aim of minimizing the bit error rate,a linear precoding scheme design is proposed based on the minimum mean-squared error(MMSE)rule in the presence of the feedback delay and channel estimation error.The proposed precoding algorithm decomposes the constrained optimization problem into three sub-convex optimization problems that are solved separately.The transmitter equipped with single antenna is subject to independent distribution,and it can be assumed that the precoding matrix is a diagonal matrix.The convex optimization problem of relay matrix is transformed into semi-definite programming problem(SDP),which can be solved by CVX toolbox.The equalizer matrix can be introduced by the gradient-based line search algorithms.Then the optimal solution is obtained by using joint iteration.The simulation results show that the proposed scheme can achieve better system performance.

关 键 词：多用户MIMO中继系统 不完全信道状态信息 预编码 反馈延迟 误比特率 

分 类 号：TN98[电子电信—信息与通信工程]