Rate-Splitting Multiple Access and its Interplay with Intelligent Reflecting Surfaces

TL;DR

This paper explores how combining rate-splitting multiple access (RSMA) with intelligent reflecting surfaces (IRS) can enhance wireless communication systems by improving spectral efficiency, robustness, and environmental control, with promising applications for beyond-5G networks.

Contribution

It introduces the concept of IRS-RSMA synergy, identifies three key improvements, and discusses future research directions for beyond-5G applications.

Findings

IRS-RSMA schemes can significantly improve spectral efficiency.

The combination enhances robustness to channel imperfections.

Numerical examples support the potential benefits for beyond-5G use cases.

Abstract

Rate-splitting multiple access (RSMA) has recently appeared as a powerful technique for improving the downlink performance of multiple-input multiple-output (MIMO) systems. By flexibly managing interference, RSMA can deliver high spectral and energy efficiency, as well as robustness to imperfect channel state information (CSI). In another development, an intelligent reflecting surface (IRS) has emerged as a method to control the wireless environment through software-configurable, near-passive, sub-wavelength reflecting elements. This article presents the potential of synergy between IRS and RSMA. Three important improvements achievable by IRS-RSMA schemes are identified, supported by insightful numerical examples, and mapped to beyond-5G use cases, along with future research directions.