Analysis of Multipath Fading and Doppler Effect with Multiple Reconfigurable Intelligent Surfaces in Mobile Wireless Networks

Guilu Wu,Fan Li,Huilin Jiang,Pan Tang

doi:10.1155/2022/5751316

Abstract

The multipath fading and Doppler effect are well-known phenomena affecting channel quality in mobile wireless communication systems. Within this context, the emergence of reconfigurable intelligence surfaces (RISs) brings a chance to achieve this goal. RISs as a potential solution are considered to be proposed in sixth generation (6G). The core idea of RISs is to change the channel characteristic from uncontrollable to controllable. This is reflected by some novel functionalities with wave absorption and abnormal reflection. In this paper, the multipath fading and Doppler effect are characterized by establishing a mathematical model from the perspective of reflectors and RISs in different mobile wireless communication processes. In addition, the solutions that improve the multipath fading and Doppler effect stemming from the movement of mobile transmitter are discussed by utilizing multiple RISs. A large number of experimental results demonstrate that the received signal strength abnormal fluctuations due to Doppler effect can be eliminated effectively by real-time control of RISs. Meanwhile, the multipath fading is also mitigated when all reflectors deployed are coated with RISs.

Highlights

Before the 6G mobile communication system, people are always exploring physical layer (PHY) technologies to improve system performance as fundamentally as possible, such as orthogonal frequency division multiplexing (OFDM) technology, massive multiple-input multiple-output (MIMO) technology, and millimeter wave communication [1]
Traditional technologies cannot bring revolutionary ideas in improving PHY layer solutions, and they are at best a supplement to existing technologies
We focus on the multipath fading and Doppler effect in reconfigurable intelligence surfaces (RISs)-assisted wireless networks

Summary

Introduction

Before the 6G mobile communication system, people are always exploring physical layer (PHY) technologies to improve system performance as fundamentally as possible, such as orthogonal frequency division multiplexing (OFDM) technology, massive multiple-input multiple-output (MIMO) technology, and millimeter wave (mmWave) communication [1]. Traditional technologies cannot bring revolutionary ideas in improving PHY layer solutions, and they are at best a supplement to existing technologies. Researchers have started research on revolutionary ideas from beyond 5G, especially on 6G technologies [2]. In this era, people expect new communication solutions could bring high spectral, energy efficiencies, reliability, and so on to satisfy the potential demands of various users and applications in future wireless communication systems, particular at the PHY

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Conclusion