Iterative Power Control for Wireless Networks with Distributed Reconfigurable Intelligent Surfaces

TL;DR

This paper proposes an iterative power control algorithm for RIS-assisted wireless networks, demonstrating power savings and improved communication reliability through joint optimization of power, receiver filters, and RIS phases.

Contribution

It introduces a novel iterative power control method for distributed RIS-assisted systems, addressing non-convex phase constraints with successive convex approximation.

Findings

Distributed RIS assistance reduces uplink power when direct links are weak.

Joint optimization improves communication reliability.

The proposed algorithm effectively handles non-convex phase constraints.

Abstract

Reconfigurable Intelligent Surfaces (RIS) are a new paradigm which, with judicious deployment and alignment, can enable more favorable propagation environments and better wireless network design. As such, they can offer a number of potential benefits for next generation wireless systems including improved coverage, better interference management and even security. In this paper, we consider an uplink next generation wireless system where each user is assisted with an RIS. We study the uplink power control problem in this distributed RIS-assisted wireless network. Specifically, we aim to minimize total uplink transmit power of all the users subject to each user's reliable communication requirements at the base station by a joint design of power, receiver filter and RIS phase matrices. We propose an iterative power control algorithm, combined with a successive convex approximation technique to solve the problem with non-convex phase constraints. Numerical results illustrate that distributed RIS assistance leads to uplink power savings when direct links are weak.