Throughput Maximization for the System of UAV as Mobile Relay Between Moving Vehicles

In recent years, due to the strong mobility and maneuverability of unmanned aerial vehicle (UAV), many scholars began to pay attention to the research of UAV as mobile relay auxiliary vehicle network. However, how to improve the throughput of the vehicle network which UAV as mobile relay is always an urgent problem. In this paper, we use the UAV as a mobile relay between two disconnected mobile vehicles to establish a new communication link to carry and forward traffic information. Firstly, we propose a throughput optimization model of UAV as inter-vehicle mobile relay under the limits of the propulsion power and the amount of data successfully transmitted by the UAV. Then, the objective function is proved to be convex, and the optimization model is solved by using Lagrange multiplier method with Karush-Kuhn-Tucker (KKT) condition. Finally, numerical simulation is carried out, we can see that the throughput of the information transmission system of the UAV as a mobile relay decreases with the increase of the amount of data required to be successfully transmitted, and it can be proved that the proposed optimization method is superior to other mobile relay methods under sufficient propulsion energy.