Energy Minimization in UAV-Aided Wireless Sensor Networks with OFDMA

The use of unmanned aerial vehicles (UAVs) as communication platform is of great practical significance in wireless sensor networks. In this paper, we study UAV-aided wireless sensor networks where a UAV is dispatched as a flying base station to transmit information to multiple ground nodes (GNs) using OFDMA (orthogonal frequency division multiple access). We aim to minimize the total UAV energy consumption, including both propulsion energy and communication-related energy, with a guarantee of the required communication throughput of each GN by jointly optimizing the OFDMA resource allocation and flight trajectory of UAV. To tackle the non-convex optimization problem, we employ block coordinate decent method and successive convex optimization technique to iteratively update the resource allocation and trajectory design. Numerical results show significant performance gains of the proposed joint optimization over two representative benchmark schemes.