Max-Min Data Rate Optimization for RIS-aided Uplink Communications with Green Constraints
Abstract
Smart radio environments aided by reconfigurable intelligent reflecting surfaces (RIS) have attracted much research attention recently. We propose a joint optimization strategy for beamforming, RIS phases, and power allocation to maximize the minimum SINR of an uplink RIS-aided communication system. The users are subject to constraints on their transmit power. We derive a closed-form expression for the beam forming vectors and a geometric programming-based solution for power allocation. We also propose two solutions for optimizing the phase shifts at the RIS, one based on the matrix lifting method and one using an approximation for the minimum function. We also propose a heuristic algorithm for optimizing quantized phase shift values. The proposed algorithms are of practical interest for systems with constraints on the maximum allowable electromagnetic field exposure. For instance, considering -element RIS, -antenna BS, and users, numerical results show that the proposed algorithm achieves close to gain in terms of minimum SINR compared to a scheme with random RIS phases.
Cite
@article{arxiv.2208.00182,
title = {Max-Min Data Rate Optimization for RIS-aided Uplink Communications with Green Constraints},
author = {Athira Subhash and Abla Kammoun and Ahmed Elzanaty and Sheetal Kalyani and Yazan H. Al-Badarneh and Mohamed-Slim Alouini},
journal= {arXiv preprint arXiv:2208.00182},
year = {2022}
}