RIS-Assisted Cooperative NOMA with SWIPT

TL;DR

This paper explores how reconfigurable intelligent surfaces can enhance cooperative NOMA networks with SWIPT by jointly optimizing system parameters to improve user rates and QoS, using advanced optimization algorithms.

Contribution

It introduces a novel joint optimization framework for RIS-assisted C-NOMA with SWIPT, employing AO, PBAGM, and SCA algorithms to solve a complex non-convex problem.

Findings

Proposed algorithm outperforms baseline schemes in simulations.

Joint optimization improves the rate of the strong user while ensuring weak user's QoS.

Demonstrates the effectiveness of RIS in cooperative NOMA with SWIPT.

Abstract

This paper studies the application of reconfigurable intelligent surface (RIS) to cooperative non-orthogonal multiple access (C-NOMA) networks with simultaneous wireless information and power transfer (SWIPT). We aim for maximizing the rate of the strong user with guaranteed weak user's quality of service (QoS) by jointly optimizing power splitting factors, beamforming coefficients, and RIS reflection coefficients in two transmission phases. The formulated problem is difficult to solve due to its complex and non-convex constraints. To tackle this challenging problem, we first use alternating optimization (AO) framework to transform it into three subproblems, and then use the penalty-based arithmetic-geometric mean approximation (PBAGM) algorithm and the successive convex approximation (SCA)-based method to solve them. Numerical results verify the superiority of the proposed algorithm over the baseline schemes.