Aerial Reconfigurable Intelligent Surface for Vehicle-to-Vehicle Communication

Vehicular-to-everything (V2X) communication is instrumental in supporting connected and autonomous vehicles. V2X link often suffers from link blockage due to the presence of obstacles. Terrestrial Reconfigurable Intelligent Surface (TRIS) has been considered for V2X to address the link blockage but it requires large number of panels and frequent switching to support a wide area. This paper proposes the use of aerial RIS (ARIS) where the RIS panel is mounted on a mobile UAV to assist the vehicle-to-vehicle (V2V) communication. First, the system model of ARIS-assisted V2V is developed. The relationship between the achievable rate performance and the system parameters such as UAV altitude, relative distance between vehicles, and the number of RIS elements are investigated. Three cases of UAV flying position including flying directly above vehicles and flying in the middle between vehicles are considered. The simulation results show that ARIS flying at the optimized altitude and in the middle between vehicles achieves the highest average achievable rate. Performance further improves as the number of RIS elements increases. These results demonstrate the potential of ARIS for assisting V2V communication.