Full-Duplex UAV Relay Positioning for Vehicular Communications with Underlay V2V Links

The unmanned aerial vehicles (UAVs) can be deployed as aerial base stations or wireless relays to increase the capacity of wireless networks. In this paper, the positioning of a full-duplex (FD) UAV as a relay to provide coverage for an FD vehicular network is investigated. In particular, given a configuration of predefined locations for the UAV, and the position of the vehicular users on the ground, a novel algorithm is proposed to find the position for the UAV to satisfy the quality of service (QoS) requirements of the vehicles in the network. The positioning problem is formulated as an ℓ
₀
minimization which is non- combinatorial, NP-hard, and finding a globally optimal solution for this problem has exponential complexity. Hence, we have approximated the nonconvex problem using ℓ
₁
norm and proposed a suboptimal algorithm to solve it. Simulation results show that by using the proposed approach the number of times that UAV can satisfy the SINR constraints increases by approximately 10% compared to a baseline scenario in which the UAV has a fixed location.