A Review of Multiple Access Techniques for Intelligent Reflecting Surface-Assisted Systems

TL;DR

This paper reviews multiple access techniques for IRS-assisted systems, highlighting the challenges and solutions for enabling efficient multi-user communication in future 6G wireless networks.

Contribution

It provides a comprehensive review of multiple access methods tailored for IRS-aided systems, addressing unique IRS characteristics and joint beamforming challenges.

Findings

Identifies key challenges in applying conventional MA techniques to IRS systems.

Summarizes recent solutions and research directions for multi-user IRS communication.

Highlights the need for novel MA strategies considering IRS-specific features.

Abstract

Intelligent Reflecting Surface (IRS) is envisioned to be a technical enabler for the sixth-generation (6G) wireless system. Its potential lies in delivering high performance while maintaining both power efficiency and cost-effectiveness. Previous studies have primarily focused on point-to-point IRS communications involving a single user. Nevertheless, a practical system must serve multiple users simultaneously. The unique characteristics of IRS, such as non-frequency-selective reflection and the necessity for joint active/passive beamforming, create obstacles to the use of conventional multiple access (MA) techniques. This motivates us to review various MA techniques to make clear their functionalities in the presence of IRS. Through this paper, our aim is to provide researchers with a comprehensive understanding of challenges and available solutions, offering insights to foster their design of efficient multiple access for IRS-aided systems.