Reconfigurable intelligent surface (RIS) for UAV communication links improvement

Reconfigurable intelligent surface (RIS) is a potential technology for energyefficient wireless communications that has recently received a lot of interest. In dynamic circumstances, combining an unmanned aerial vehicle with RIS (UAV-RIS) can provide on-demand deployment services. The energy of the battery-powered UAV, however, will limit the benefits of UAV-RIS. We propose an innovative energy harvesting strategy for Simultaneous Wireless Information and Power Transfer (SWIPT) in UAV-RIS (Unmanned Aerial Vehicle-Reflecting Intelligent Surface) systems. Unlike previous studies, our approach involves segmenting passive reflected arrays in geometric space, enabling the concurrent transfer of information and energy harvesting from impinging radio-frequency (RF) signals. Additionally, we are developing a Deep Deterministic Policy Gradient (DDPG) technique to dynamically allocate resources of UAV-RIS in both time and space domains, aiming to maximize the overall harvested energy while maintaining communication quality for individual users. Our simulations demonstrate a significant performance enhancement of the proposed UAV-RIS SWIPT system compared to existing benchmarks. Key Words: Deep Deterministic Policy Gradient, Reconfigurable intelligent surface, UAV