Jointly Optimized 3D Drone Mounted Base Station Deployment and User Association in Drone Assisted Mobile Access Networks

In drone assisted mobile networks, a drone mounted base station (DBS) is deployed over a hotspot area to help user equipments (UEs) download their traffic from the macro base station (MBS), thus improving the throughput and spectrum efficiency (SE) of the UEs. Finding the optimal 3D position of the DBS to maximize the overall SE of the UEs in the hotspot area is challenging because the 3D DBS placement and user association problems are coupled together. In this paper, we formulate the problem of jointly optimizing the 3D DBS placement and user association to maximize the overall SE in the context of drone assisted mobile networks. The spectrum efficiency aware DBS placement and user association (STAR) algorithm is designed to decompose the original problem into two subproblems, i.e., user association and DBS placement, and to iteratively solve the two subproblems until the overall SE of the hotspot area cannot be improved further. The performance of STAR is demonstrated via extensive simulations.