Intelligent Reflecting Surface-Aided Wireless Communications: A Tutorial

TLDR

Intelligent reflecting surfaces enable dynamic control of radio propagation by tuning many passive elements, promising cost‑effective capacity growth, yet they face challenges in reflection optimization, channel estimation, and deployment. This tutorial reviews IRS‑aided wireless communications, outlining reflection and channel models, hardware architecture, practical constraints, and applications, and highlights future research directions. The authors provide a comprehensive tutorial overview, elaborating the reflection and channel models, hardware architecture, practical constraints, and applications of IRS‑aided wireless networks.

Abstract

Intelligent reflecting surface (IRS) is an enabling technology to engineer the radio signal propagation in wireless networks. By smartly tuning the signal reflection via a large number of low-cost passive reflecting elements, IRS is capable of dynamically altering wireless channels to enhance the communication performance. It is thus expected that the new IRS-aided hybrid wireless network comprising both active and passive components will be highly promising to achieve a sustainable capacity growth cost-effectively in the future. Despite its great potential, IRS faces new challenges to be efficiently integrated into wireless networks, such as reflection optimization, channel estimation, and deployment from communication design perspectives. In this paper, we provide a tutorial overview of IRS-aided wireless communications to address the above issues, and elaborate its reflection and channel models, hardware architecture and practical constraints, as well as various appealing applications in wireless networks. Moreover, we highlight important directions worthy of further investigation in future work.