Intelligent Reflecting Surface Aided Wireless Communications: A Tutorial

TL;DR

This tutorial reviews the emerging use of intelligent reflecting surfaces (IRS) in wireless communications, focusing on their models, challenges, and potential to enhance network performance cost-effectively.

Contribution

It provides a comprehensive overview of IRS technology, including models, hardware, challenges, and applications, highlighting future research directions.

Findings

IRS can dynamically alter wireless channels to improve performance

Challenges include reflection optimization and channel estimation

IRS has promising applications in future wireless networks

Abstract

Intelligent reflecting surface (IRS) is an enabling technology to engineer the radio signal prorogation 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 communication 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.