Low-Resolution RIS-Aided Multiuser MIMO Signaling

A multi-antenna aided base station (BS) supporting several downlink users with the aid of a reconfigurable intelligent surface (RIS) programmable reflecting elements (PREs) is considered. Low-resolution PREs constrained by set sparse discrete values are used for reasons cost-efficiency. Our challenging objective to jointly design beamformers at BS and RIS’s improving throughput all maximizing their geometric-mean, under variety different access schemes. This constitutes computationally problem mixed continuous-discrete optimization, because each user’s complicated function both continuous-valued beamformer weights discrete-valued PREs. We develop low-complexity algorithms, which iterate directly evaluating closed-form expressions. simulation results show advantages non-orthogonal multiple access-aided signaling, allows decode part multi-user interference enhancing throughput.