Optimizing 3-D Placement of Multiple UAVs Based on Taguchi's Method

Due to the characteristics of high maneuverability, low cost, and high line-of-sight (LoS) probability, unmanned aerial vehicles (UAVs) have attracted more and more attention in the field of communications recently. Using UAVs as a mobile aerial base station (BS), commonly referred to as UAV-aided communication, can provide a quick and flexible solution for sudden communication needs and coverage holes. To maximize the coverage effect, effective three-dimensional (3-D) deployment is crucial. As a result of the complexity of air to ground channels and interference between UAVs and BSs, 3-D placement of UAVs is currently one of the main challenges for UAV-aided communications. In this paper, Taguchi's method is used for 3-D placement optimization of multiple UAVs, aiming to make up for the coverage holes and assist the ground cellular network to cover the area as seamlessly as possible. Simulation results indicate that Taguchi's method can effectively improve the coverage ratio of the area by optimizing the 3-D placement of UAVs, and the optimization effect is better than simulated annealing algorithm.