Analysis on Time-Variant Air-to-Ground Radio Communication Channel for Rotary-Wing UAVs

With the inertial measurement unit (IMU) and motor technology improvement, the unmanned aerial vehicles (UAVs) become more accessible for different applications. Among the fixed-wing and the rotary- wing UAV, the former is advantageous in having no runway and small craft size which are more attractive to users. The rotary-wing UAVs is used to provide real-time monitor and control on interest targets for ground users. However, the effects of propellers are not addressed in existing rotary-wing UAV channel models. In this paper, we propose a simple air-to-ground radio communication channel for rotary-wing UAVs considering the propellers. Analysis and results are presented based on the model. The results show the maximum of Doppler shifts for all simulated frequencies exceed 300Hz, the requirement of the LTE, and there is potential risks adapt the current communication system directly for serious time-variant multipath and Doppler frequency shift channel issues.