Reconfigurable-Intelligent-Surface Empowered Wireless Communications: Challenges and Opportunities

TL;DR

This paper reviews the emerging use of reconfigurable intelligent surfaces (RISs) in wireless communications, highlighting key challenges like channel estimation and system design, and discusses future research directions including security and edge intelligence.

Contribution

It provides a comprehensive overview of physical-layer challenges and solutions for RIS integration in wireless networks, and explores promising future research avenues.

Findings

Summarizes state-of-the-art solutions for RIS challenges

Identifies key physical-layer challenges in RIS deployment

Discusses future research directions including security and intelligence

Abstract

Reconfigurable intelligent surfaces (RISs) are regarded as a promising emerging hardware technology to improve the spectrum and energy efficiency of wireless networks by artificially reconfiguring the propagation environment of electromagnetic waves. Due to the unique advantages in enhancing wireless channel capacity, RISs have recently become a hot research topic. In this article, we focus on three fundamental physical-layer challenges for the incorporation of RISs into wireless networks, namely, channel state information acquisition, passive information transfer, and low-complexity robust system design. We summarize the state-of-the-art solutions and explore potential research directions. Furthermore, we discuss other promising research directions of RISs, including edge intelligence and physical-layer security.