Tropospheric Communication with UAV Relay: Impact of Meteorological Conditions and SDR Validation

Abstract

The paper considers the possibilities of using unmanned aerial vehicles as high-altitude relays for temporary deployment of tropospheric communication networks in emergency conditions. Modern approaches to long-range radio communication organization are analyzed and their limitations are outlined. A concept of a hybrid system at 5 GHz frequency with UAV at 200-1000 m altitude is proposed, combining the advantages of tropospheric scattering and line of sight. A methodology for assessing the impact of precipitation, fog and snow on maximum communication range based on link energy balance is developed. Simulation results are compared with experimental data obtained on an LTE training model based on the LimeSDR SDR platform. It is shown that moderate rain reduces the range by almost half, but increasing the UAV altitude partially compensates for losses. Recommendations for adaptive system operation in various meteorological conditions are proposed. The practical value of the work lies in creating a methodology for designing communication systems with UAV relays, taking into account real operational limitations. The obtained results can be used in the design of emergency communication systems for rescue services, military units and humanitarian missions.