IRS-Aided Hybrid FSO/RF Communication System with Selection Combining

Free space optics (FSO) and radio frequency (RF) communication links can be used to complement each other, as both the systems are impacted differently by environmental impediments, i.e., fog is a major impairment in an FSO system, whereas rain impacts RF systems. This paper proposes an intelligent reflecting surfaces (IRS)-assisted hybrid FSOIRF system with selection combining at the receiver, wherein the data is transmitted via both the FSO and RF links. The at-mospheric turbulence of FSO link is modeled using the Gamma-Gamma distribution and the Nakagami-m distribution is used to characterize the fading in the RF link. The expressions for outage probability and average symbol error rate are obtained for the proposed system. Further, the performance of the proposed system is analyzed numerically, followed by reasoning. Finally, we compare the proposed IRS-assisted hybrid FSO/RF system with the existing hybrid FSO/RF system without IRS, a direct link FSO. and an IRS-assisted FSO system.