A 3D Non-Stationary Wideband GBSM for Low-Altitude UAV Channels in Rail Environments

Abstract

In recent years, low-altitude unmanned aerial vehicles (UAVs) have attracted more and more attention across various fields. Accurate channel modelling is critical for the design and performance evaluation of low-altitude UAV communication systems, making it an emerging research hotspot. This paper presents a three-dimensional (3D) wideband non-stationary Geometry-Based Stochastic Channel Model (GBSM) for low-altitude UAV communications. Distinct from existing modelling frameworks, the proposed model integrates air-to-air (A2A) and air-to-ground (A2G) scenarios into a generalised channel model. Moreover, a two-state continuous-time Markov process is employed to characterise the dynamic behaviours of scattering cluster birth and death. And key statistical properties, including space-time-frequency correlation and Doppler power spectral density (DPSD), are derived to quantify the channel model. To address computational complexity challenges, a corresponding simulation model is further developed. Simulation results verify that the proposed model effectively captures the channel behaviours of low-altitude UAV communication systems.