Joint optimization of position and beamforming vectors in UAV-assisted wireless communication system

Abstract

UAV-assisted wireless communication has the advantages of flexible deployment and wide coverage. However, it still has some disadvantages such as high path loss, low throughput and low transmission capability. The beamforming technology is introduced into UAV-assisted wireless communication, which can effectively compensate the path loss and alleviate the interference. Therefore, a UAV-assisted wireless communication system model is constructed in this paper, which is equipped with uniform planar array on the ground base station and UAV to achieve beamforming, so as to maximize the capacity of target nodes. In order to solve the non-convex problem with high-dimensional and highly-coupled optimization variables, firstly, the block coordinate descent method is used to transform the original problem into two sub-problems: position optimization of relay UAV and beamforming vector optimization. And then the continuous convex approximation method is used to transform two sub-problems into convex optimization problems for solving. The simulation results show that the proposed method can effectively improve the capacity of the target node.