Non-Stationary Low-Altitude UAV MIMO A2G Channel Model With Rotation and Arbitrary Trajectories

In this paper, a three-dimensional (3D) non-stationary geometry-based stochastic model (GBSM) is proposed for low-altitude unmanned aerial vehicles (UAVs) multiple-input-multiple-output (MIMO) air-to-ground (A2G) channel. In the proposed model, both UAV rotation and arbitrary trajectories are taken into account. UAV rotation is described by a 2D Gauss-Markov random mobility model (RMM), while UAV arbitrary trajectories are characterized by a 3D revised Gauss-Markov RMM. The time-varying parameters of multipath components (MPCs), such as distances, angles of arrival (AoAs), and angles of departure (AoDs), are calculated based on the proposed model. In addition, the expressions of the space-time correlation function (CF) and Doppler power spectral density (PSD) are also derived. Numerous numerical simulations are conducted and the simulation results reveal that the UAV rotational motion causes channel non-stationarity in space domain, and the mobility characteristics of UAV along with arbitrary trajectories cause channel time domain non-stationary. Finally, the accuracy of the model is verified by comparing with the available measurement data.