Joint Unmanned Aerial Vehicle Location and Beamforming and Caching Optimization for Cache-Enabled Multi-Unmanned-Aerial-Vehicle Networks

Due to the advantages such as high flexibility, low cost and easy implementation offered by unmanned aerial vehicles (UAVs), a UAV-assisted network is regard an appealing solution seamless coverage, disaster-tolerant on-demand wireless system. In this paper, we focus on downlink transmission in cache-enabled communication network, where UAVs cache popular content from macro base station advance cooperatively transfer users. We aim minimize average latency of system formulate optimization problem that jointly optimizes UAV location, beamforming caching strategy. However, formulated very challenging because its non-convexity highly coupled variables. To solve resulting efficiently, decompose it into two subproblems, namely location optimization, strategy optimization. The first subproblem NP-hard joint problem, while second one linear programing problem. By adopting first-order Taylor expansion, propose convex algorithm based difference-of-convex (DC) method. Specifically, bring out method apply approximation DC-based algorithm, which particularly suitable problems involving complicated summations. numerical results demonstrate proposed iterative can efficiently reduce