RIS辅助MIMO NOMA系统中利用统计CSI的下行传输方法  

Downlink Transmission for RIS-Assisted MIMO NOMA by Exploiting Statistical CSI

作　　者：陆佳程 王斌[1] 张军 倪艺洋 LU Jiacheng;WANG Bin;ZHANG Jun;NI Yiyang(School of Communications and Information Engineering,Nanjing University of Posts and Telecommunications,Nanjing 210003,China;School of Physics and Information Engineering,Jiangsu Second Normal University,Nanjing 210013,China)

机构地区：[1]南京邮电大学通信与信息工程学院,南京210003 [2]江苏第二师范学院物理与信息工程学院,南京210013

出　　处：《电子与信息学报》2024年第4期1257-1265,共9页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(62071247);江苏省高校自然科学基金(BK2021022532)。

摘　　要：针对可重构智能反射表面(RIS)辅助多输入多输出(MIMO)非正交多址接入(NOMA)下行传输系统,该文提出利用统计信道状态信息(CSI)的基站发送协方差矩阵与RIS相移矩阵设计方法。首先,在莱斯空间相关信道假设下,利用大维随机矩阵理论,推导了RIS辅助MIMO NOMA系统遍历和速率的确定性表达式;然后,在弱用户速率约束与发送功率受限的条件下,通过最大化确定性大系统近似和速率,利用统计CSI,分别设计了强、弱用户的次优发送协方差矩阵和RIS的相移矩阵。仿真结果表明,所推导的近似表达式具有很好的近似效果,所设计的发送协方差矩阵和相移矩阵能显著提升系统的和速率。For a Reconfigurable Intelligent Surface(RIS)-assisted Multiple Input Multiple Output(MIMO)Non-Orthogonal Multiple Access(NOMA)downlink system,the transmit covariances matrix at the base station and the phase-shifting matrix at the RIS are jointly designed based on statistical Channel State Information(CSI).First,in the spatial correlated Rician channel,a deterministic large-system approximation for the ergodic sum rate is obtained for an RIS-assisted MIMO-NOMA system by resorting to the large-dimensional random matrix theory.Then,by maximizing the approximated sum rate,the transmit covariances matrix for the strong and weak user as well as the phase-shifting matrix at the RIS are designed based on statistical CSI under the constraints of total transmit power and the rates threshold for weak user.The simulations validate the high accuracy of our approximations and our proposed transmit covariances and phase-shifting matrix can improve the system performances significantly.

关 键 词：统计信道状态信息 非正交多址接入 可重构智能反射表面 发送协方差 大维随机矩阵理论 

分 类 号：TN92[电子电信—通信与信息系统]