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
Key words
Statistical Channel State Information (CSI)/Non-Orthogonal Multiple Access (NOMA)/Reconfigurable Intelligent Surface (RIS)/Transmit covariances/Large-dimensional random matrix theory
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