Energy-efficient power control and altitude planning for UAV-based vehicular communications in 5G NR-V2X networks

Unmanned aerial vehicles (UAVs) are becoming increasingly popular in various industries, including telecommunications. In the realm of 5G new radio vehicle-to-everything (NR-V2X) networks, UAVs can be used as mobile base stations (UAV-BS) to provide vehicular communications. However, effective power control and altitude planning algorithms are required to maximize the energy efficiency (EE) of these UAV-BS systems. In this article, we propose an energy-efficient power control and altitude planning algorithm for UAV-BS in NR-V2X networks. We formulate the optimization problem of maximizing the system's EE while considering the reliability requirements of vehicular users, the limitations of UAV-BS hovering altitude, and the feasibility of transmission power levels. The problem is nonconvex, and we address this by reformulating it into a convex problem using the Dinkelbach and alternating optimization methods. The simulation results demonstrate that the proposed algorithm closely achieves the performance of exhaustive search while it is more computationally efficient. Moreover, our algorithm by jointly optimizing transmission power and hovering altitude performs better than other schemes proposed in the literature, as shown through our simulation results.