UAV Aerial Channel Modeling Based On GBSM Method

With the development of flight control and electronics technologies,UAVs are active in increasingly broad military and civilian application scenarios.As an important part of the SAGSINs,UAV aerial communication has attracted many researchers’ attention.A reliable and accurate channel model which could accurately describe the wireless propagation channel in the communication scenario,is the important basis for the actual design optimization of the UAV communication system.First,this paper analyzes the characteristics of UAV air-to-air communication scenes and movement features,then based on GBSM method,it establishes a dual-sphere channel model for high-altitude fixed-wing UAV aerial scenarios and single-cylinder channel model for low-altitude multi-rotor UAV scenarios.Based on the simplified ray tracing,these models include direct line-of-sight and non-line-of-sight propagation components.Using the superposition of sine wave method,the reference channel model and simulation ones are derived.Secondly,in dual-sphere model,we analyze analyses the impact of UAV speed changes,moving directions and scattering environment on high-altitude channel statistics parameters,e.g.,space-time correlation function and Doppler power spectral density function.The simulation results provide a reference for using different communication technologies to improve the quality of communication under different flight conditions.Besides,the simulation results show that the statistical channel propagation characteristics of the reference channel model and that of the simulation model have a good fit,which verifies the practicability and correctness of the simulation model.Finally,in the single-cylinder geometric channel model established for the complex environment of the low-altitude city,the lightweight structure of multi-rotor UAVs are susceptible to random airflow disturbance or abnormal engine vibration.Therefore,we use the sinusoidal random process to simulate the elevation angle variation of airborne antenna array caused by UAV jitter.Theoretical derivation and simulation results show that the lower channel space-time correlation and non-stationary under UAV jitter.Next,we compare the channel time correlation functions when the UAV randomly jitters during hovering or moving state,it shows that the movement will further reduce the time correlation.By setting parameters in models,we compare the statistical characteristics of channel propagation in high/low-altitude A2 A scenarios and air-to-Ground(A2G)scenarios,showing the impact of different 3D communication scenarios on propagation channel and the abstract mapping between the scattering environment and the geometric channel model,which provide a reference for the selection of geometry in GBSM method.