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Two-Timescale Design for Reconfigurable Intelligent Surface-Aided Massive MIMO Systems with Imperfect CSI

Zhi, Kangda, Pan, Cunhua, Ren, Hong, Wang, Kezhi, Elkashlan, Maged, Di Renzo, Marco, Schober, Robert, Vincent Poor, H., Wang, Jiangzhou, Hanzo, Lajos and others. (2022) Two-Timescale Design for Reconfigurable Intelligent Surface-Aided Massive MIMO Systems with Imperfect CSI. IEEE Transactions on Information Theory, . ISSN 0018-9448. E-ISSN 1557-9654. (doi:10.1109/tit.2022.3227538) (KAR id:99203)


This paper investigates the two-timescale transmission scheme for reconfigurable intelligent surface (RIS)-aided massive multiple-input multiple-output (MIMO) systems, where the beamforming at the base station (BS) is adapted to the rapidly-changing instantaneous channel state information (CSI), while the nearly-passive beamforming at the RIS is adapted to the slowly-changing statistical CSI. Specifically, we first consider a system model with spatially independent Rician fading channels, which leads to tractable expressions and offers analytical insights on the power scaling laws and on the impact of various system parameters. Then, we analyze a more general system model with spatially correlated Rician fading channels and consider the impact of electromagnetic interference (EMI) caused by any uncontrollable sources present in the considered environment. For both case studies, we apply the linear minimum mean square error (LMMSE) estimator to estimate the aggregated channel from the users to the BS, utilize the low-complexity maximal ratio combining (MRC) detector, and derive a closed-form expression for a lower bound of the achievable rate. Besides, an accelerated gradient ascent-based algorithm is proposed for solving the minimum user rate maximization problem. Numerical results show that, in the considered setup, the spatially independent model without EMI is sufficiently accurate when the inter-distance of the RIS elements is sufficiently large and the EMI is mild. In the presence of spatial correlation, we show that an RIS can better tailor the wireless environment. Furthermore, it is shown that deploying an RIS in a massive MIMO network brings significant gains when the RIS is deployed close to the cell-edge users. On the other hand, the gains obtained by the users distributed over a large area are shown to be modest.

Item Type: Article
DOI/Identification number: 10.1109/tit.2022.3227538
Additional information: © 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works
Uncontrolled keywords: Reconfigurable intelligent surface (RIS); massive MIMO; two-timescale transmission scheme; channel estimation; spatial correlation; electromagnetic interference (EMI)
Subjects: Q Science
Divisions: Divisions > Division of Computing, Engineering and Mathematical Sciences > School of Engineering and Digital Arts
SWORD Depositor: JISC Publications Router
Depositing User: JISC Publications Router
Date Deposited: 13 Feb 2023 15:57 UTC
Last Modified: 14 Feb 2023 11:52 UTC
Resource URI: (The current URI for this page, for reference purposes)

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