Reconfigurable Intelligent Surfaces for Enhanced Wireless Communication

Abstract

The future of mobile communications seems promising, with possible new applications and demanding needs for forthcoming sixth-generation (6G) and subsequent wireless networks. Since the advent of modern wireless communications, the propagation medium has been regarded as a stochastic entity between the transmitter and receiver, which diminishes the quality of the received signal due to the unpredictable interactions of transmitted radio waves with surrounding objects. The recent emergence of reconfigurable intelligent surfaces in wireless communications allows network operators to manipulate the scattering, reflection, and refraction properties of radiowaves, therefore mitigating the adverse impacts of natural wireless propagation. Recent findings indicate that reconfigurable intelligent surfaces may proficiently manipulate the wavefront, including phase, amplitude, frequency, and polarization of incoming signals, without necessitating intricate decoding, encoding, or radio frequency processing procedures. This article aims to furnish readers with a comprehensive overview and historical context of cutting-edge solutions, elucidate the fundamental distinctions from other technologies, identify critical open research challenges, and explain why the implementation of reconfigurable intelligent surfaces requires a reevaluation of the communication-theoretic models currently utilized in wireless networks. This paper examines the theoretical performance limitations of reconfigurable intelligent surface-assisted communication systems via mathematical methodologies and discusses possible applications of intelligent surfaces in 6G and future wireless networks