Nallagonda, V.Krishnan, P.2026-02-052021Optical and Quantum Electronics, 2021, 53, 9, pp. -3068919https://doi.org/10.1007/s11082-021-03188-0https://idr.nitk.ac.in/handle/123456789/23093The increasing availability of unmanned aerial vehicles (UAVs) is an exciting part of future emerging technology with advanced scientific and industrial interests. Free space optical (FSO) communications’ ability to offer very high data rates and the mobility of unmanned aerial vehicle (UAV) flying platforms make the delivery of Fifth-Generation (5G) wireless networking services appealing to FSO-UAV-based solutions. UAVs play a greater role in end-to-end delivery in next- generation wireless networking systems, serving as a base station, capacity enhancement, high data access, and other disaster management systems. To establish a link between unmanned aerial vehicles and ground stations, FSO can be applied. But, the different weather conditions liken rain, fog effects on the performance of the FSO link, contributing to the loss of the signal. In this paper, we proposed polarization shift keying (POLSK) modulated FSO link based UAV–UAV communication system for 6G beyond applications. We examine the effect of different weather conditions such as rain, fog on the bit error rate (BER) performance of the proposed system. Novel closed-form expressions for UAV–UAV based FSO propagation channel are derived, and BER performance is investigated under different weather conditions. Fog and rain are the main limiting factors mitigated in this paper by suitable mitigation techniques by increasing receiver field of view. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.AntennasBit error rateDisaster preventionDisastersFogInformation managementMobile telecommunication systemsOptical communicationOptical linksPolarizationRainSpace platformsUnmanned aerial vehicles (UAV)Wireless networksBit error rate (BER) performanceBit error rate analysisClosed-form expressionEmerging technologiesFree Space Optical communicationFree-space optical linkMitigation techniquesPolarization shift keying5G mobile communication systems