Performance Analysis And Optimization For V2v-Assisted Uav Communications In Vehicular Networks

Deploying unmanned aerial vehicles (UAVs) as flying base stations (BSs) is a promising solution to alleviate the burden of communication infrastructure during the peak-traffic hours. However, when a UAV is deployed as a flying BS to serve the vehicle users in the hotspot, and the vehicle-to-vehicle (V2V) communication is introduced to further improve the network capacity, the performance analysis and optimization problems have not gained well investigated. In this paper, aforementioned problems are carefully studied from a statistical point of view, where the system performance is captured by the users' successful service probability. Specifically, we first derive the successful service probability for the UAV-to-vehicle (U2V) transmission. Meanwhile, taking those important factors, i.e., vehicle mobility and social proximity, into account, we estimate the successful service probability for the V2V transmission. The average successful service probability for the considered scenario is then derived. Based on the mathematical analysis results, we further improve the system performance by adjusting the UAV's altitude position, where the UAV deployment problem is formulated as a service probability maximization problem. To find the optimal solution, a particle swarm optimization algorithm is proposed. Finally, numerical simulations are conducted to verify the theoretical analysis and the efficiency of our proposed scheme.