RIS-Aided Multiple-Input Multiple-Output Broadcast Channel Capacity

• Published in: IEEE transactions on communications 2024-01, Vol.72 (1), p.1-1
• Main Authors: Tuan, H. D., Nasir, A. A., Dutkiewicz, E., Poor, H. V., Hanzo, L.
• Format: Article
• Language: English
• Subjects: Algorithms; Antennas; Beamforming; Channel capacity; Computational modeling; Information theory; Linear programming; MIMO communication; Minimax techniques; mixed discrete continuous optimization; Optimization; Optimized production technology; Reconfigurable intelligent surface (RIS )-aided communication; scalable algorithms; Sensors; sum capacity
• ISSN: 0090-6778; 1558-0857
• DOI: 10.1109/TCOMM.2023.3321909

Scalable algorithms are conceived for obtaining the sum-rate capacity of the reconfigurable intelligent surface (RIS)-aided multiuser (MU) multiple-input multiple-output (MIMO) broadcast channel (BC), where a multi-antenna base station (BS) transmits signals to multi-antenna users with the help of an RIS equipped with a massive number of finite-resolution programmable reflecting elements (PREs). As a byproduct, scalable path-following algorithms emerge for determining the sum-rate capacity of the conventional MIMO BCs, closing a long-standing open problem of information theory. The paper also develops scalable algorithms for maximizing the minimum rate (max-min rate optimization) of the users achieved by the joint design of RIS's PRE and transmit beamforming for such an RIS-aided BC. The simulations provided confirm the high performance achieved by the algorithms developed, despite their low computational complexity.