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

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.

Time hysteresis-switching algorithm assisted dual-hop relaying for hybrid FSO/RF system

“…Therefore, it is a short-distance, high bandwidth, high data-rate (up to 10Gbps), electromagnetic pollution free unlicensed-spectrum which is easy to deploy. FSO links are used as backhaul for wireless cellular, Intercampus Connectivity (near terrestrial FSO), etc [1].…”

“…As a result of the short range of FSO and mm-RF transmissions [13][14][15][16], distributed network architecture is needed for backhaul connectivity. As shown in Figure (1), backhaul data traffic is relayed from one base-station node to the adjacent base-station node and then forwarded to the end base-station node. In earlier works, hybrid FSO-RF systems have been investigated where FSO transmission links have mostly been employed as last-mile connectivity.…”