Performance Optimization of Intelligent- Reflecting-Surfaces assisted-FSO link

Abstract

Abstract Free space optics (FSO) plays key role to establish a link in targeted remote and uncovered area of skip-zones where wireline (optical fiber cable) is not easy to deploy. FSO communication has been opted as a promising solution for reliable, low latency, cost effective and unlicensed spectrum wireless backhaul connectivity for 5G and beyond wireless communication system. The foremost impairments of FSO communication are atmospheric turbulence and line-of-sight (LoS) requirement between Source to Destination. To relax the LoS requirement of FSO communication, a novel scheme called intelligent reflecting surface (IRS)-assisted FSO communication is a very reliable and effective alternative solution like first-last mile access connectivity. In this work, an IRS-based FSO and radio frequency (RF) links are modeled. IRS-assisted FSO link achieves average symbol error-rate (ASER) of 10− 6 for SNR of 30 dB while FSO link with Gamma-Gamma and Malaga (M) distribution gives ASER value of 10− 3 and 10− 2 respectively. In Optical-multiple IRS-assisted FSO links, increase in number of reflecting elements improves ASER upto 10− 8 at SNR of 20dB.