SLIPT Enabled Ground-to-UAV FSO Communication for SAGNET in 6G-IoT Systems

The development of 6G-IoT aims to provide seamless connectivity across space, air, ground, sea, and underwater networks. Uncrewed Aerial Vehicles (UAVs) with Free-Space Optical (FSO) communication are crucial in these networks, but their power limitations challenge sustained operation. This paper explores Simultaneous Lightwave Information and Power Transfer (SLIPT) for Ground-to-UAV (G2U) FSO communication, focusing on four methods: AC-DC separation (ADS), time switching (TS), power splitting (PS), and time switching-power splitting (TSPS). We derive closed-form expressions for harvested energy, Symbol Error Rate (SER), and outage probability under a generalized Málaga distribution, considering atmospheric attenuation, turbulence, and pointing errors. Our study examines the impact of SLIPT methods on harvested energy and SER, analyzing link distances, atmospheric conditions, pointing errors, and weather. Optimal beamwidth and receiver Field of View (FOV) values are identified to maximize energy and minimize SER. Findings show the TSPS method yields the highest harvested energy, achieving 0.04 mJ under strong turbulence, due to its dual-phase approach. The proposed SLIPT methods enhance UAV energy efficiency and improve SER performance, achieving a SER of10⁻⁴at an SNR of 30 dB, providing key insights for 6G-IoT optimization.