Performance Analysis of a UAV-Assisted RF/FSO Relaying Systems for Internet of Vehicles

The Internet of Vehicles (IoV), as a development and complement of the Internet of Thing, has attracted extensive attention and is expected to play a crucial role in human society with the matured space-air-ground integrated networks (SAGIN). Here, we devote ourselves to establish and investigate a unmanned aerial vehicle (UAV)-assisted radio-frequency (RF)/free space optical (FSO) communication system under the amplified-and-forward protocol with variable gain. More specifically, we assume the RF link follows kappa - mu fading and the FSO link experiences Malaga fading, which can characterize the atmospheric turbulence under weak-to-strong condition excellently. In addition, both the pointing errors impairment and the detection techniques for the FSO link are also taken into account. Novel analytical expressions for the end-to-end system, e.g., the cumulative distribution function, probability density function, and moment generating function, are proposed. By capitalizing on these results, some system metrics of the UAV-assisted relaying system are given with the Meijer's G function. To providing more insights for this UAV-assisted system for SAGIN, high signal-to-noise approximations of these metrics are also presented. Furthermore, the approximated expressions for the outage probability and average BER are given in presence of nonpointing error effect. Finally, all these analytical results are validated with the Monte Carlo simulations.