Fair Energy and Data Rate Maximization in UAV-Powered IoT-Satellite Integrated Networks

Non-Terrestrial Networks represent a valuable solution for providing connectivity to Internet of Things (IoT) devices in remote areas, where classical infrastructure is unavailable. Due to the low-power nature of IoT devices, an Unmanned Aerial Vehicle (UAV) can prevent the energy depletion of these Ground Nodes (GNs) by employing Wireless Power Transfer through an array antenna. Starting from the mathematical modeling of such a scenario, two Mixed-Integer Non-Linear Programming problems are formulated to fairly maximize (i) the energy distribution and (ii) the total amount of data transmitted to a Low Earth Orbit CubeSat. Therefore, it is necessary to optimize the drone kinematics, the transmission scheduling plan, and the beamforming vectors of the array antenna. To cope with their non-convexity, both problems are mathematically manipulated to reach a tractable form, for which two optimization algorithms are proposed and their complexity analyzed. To prove the effectiveness of the overall solution, a comprehensive simulation campaign is conducted under several parameter settings, such as number of GNs and UAV antenna elements with different transmission power levels. Finally, the proposal is compared with a baseline, which confirms the superiority of the proposal up to 7 times in terms of total transmitted data.