Secure Satellite–Vehicle Communications With Randomly Distributed Vehicles on Different Roads

With the development of satellite communication technology, the application of satellites in the Internet of Vehicles (IoV) system can effectively solve the limitations and deficiencies of ground communication networks. In this article, we investigate the security outage performance of a satellite–vehicle communication system consisting of a satellite ($S$), a legitimate receiving vehicle ($C$), and an eavesdropping vehicle ($E$), where $C$ and $E$ are randomly located on two different roads within the coverage area of $S$ and randomly distributed on their respective roads. The downlink communication links between $S$ and these terrestrial vehicles are assumed to suffer the shadowed-Rician fading. Then, the secrecy outage probability (SOP) is studied under the most straightforward case that $ C$ and $E$ are equipped with a single antenna. Next, we extend to the more common scenario where both $C$ and $E$ adopt multiple antennas by deriving the analytical expression for the SOP. Finally, numerical results are presented to verify our proposed analytical models.