Searchlight-Assisted Feeder Links for UAV-Based VLC Networks

Reliance on unmanned aerial vehicles (UAVs) to support on-demand wireless coverage offers flexible solutions for data transfer in various applications. For use cases where light-emitting diode (LED)-based luminaires are mounted on UAVs, adopting visible-light communication (VLC) to provide simultaneous lighting and communication, enables efficient resource utilization and support of high-speed connectivity. However, providing reliable wireless coverage in UAV networks requires dependable feeder link solutions. In this work, we propose searchlight-assisted feeder link systems for VLC-enabled UAV networks. By using LED-based searchlights for signal transmission at ground stations, the proposed solutions offer reduced tracking complexity and robust link performance in terms of link outages due to pointing errors. Furthermore, we propose a reconfigurable intelligent surface (RIS)-assisted feeder link system to support multiple UAVs using a single search-light. Low-complexity optimization of RISs is introduced to minimize link outages in scenarios involving multi-UAV networks. The effectiveness of the proposed schemes is highlighted through numerical simulations.