Performance Analysis of Hybrid FSO/RF Empowered V2N Communications with Multiple Relay Units

This paper considers mixed radio frequency (RF) and hybrid free space optics (FSO)/RF communications for information transfer between vehicles and the network where multiple infrastructures nodes, such as street lights, traffic lights, signboards, etc., act as relay units. Vehicles communicate with nearby infrastructure nodes in the first transmission phase using an RF link. In the next phase, an infrastructure node corresponding to the maximum signal-to-noise ratio (SNR) is selected to forward the signal to the base station using a hybrid FSO/RF link. An RF link is used as a backup connection to increase the system's reliability. To get practical insights, atmospheric turbulence-induced fading, pointing errors, and atmospheric attenuation, which may affect the FSO link's performance, are considered. In addition, the base station is deployed with multiple antennas. It exploits maximum-ratio combining when the RF link is active to improve end-to-end system performance. We derive closed-form expressions for the outage probability and system throughput to analyze the system's performance. We include the simulation results to verify that all the derived analytical findings are accurate.