Time Stationary RS-GBSM for UAV Narrowband Channels

To successfully support the design and performance of unmanned aerial vehicle (UAV) communication systems, we propose a novel three-dimensional (3D) geometry-based stochastic model (GBSM), i.e., a two-cylinder model, for UAV multiple-input multiple-output (MIMO) Ricean fading channels. The received signal is a sum of the line-of-sight (LoS) component, single-bounced (SB) rays at the UAV side, SB rays at the ground station side, SB rays on the ground, and double-bounced (DB) rays. This makes our model adaptable to a wide variety of UAV communication scenarios. More importantly, the proposed UAV model is the first two-cylinder model that considers ground reflections. Moreover, our model has the ability to investigate the impact of some unique UAV-related parameters, e.g., the UAV’s moving direction, UAV’s altitude, and antenna orientation, on channel characteristics in a 3D non-isotropic propagation environment. From the proposed model, we derive and study some significant statistical properties, including the space-time correlation function (STCF), Doppler power spectral density (PSD), envelope level crossing rate (LCR), and average fade duration (AFD). Some numerical results and interesting observations are provided, which can be considered useful guidance for the design of UAV-MIMO communication systems. Finally, the utility of our model is verified by the close agreement between the theoretical results and measurement data.