Channel Modeling and Characteristics Analysis of UAV-to-Ground Communication Systems with Random UAV Trajectories

To achieve the ambitious goals of global-coverage, complete applications, and all-spectra in the sixth generation (6G) mobile networks, channel modeling and characteristics analysis are crucial. This paper proposes an unmanned aerial vehicle (UAV)-to-ground channel model with massive multipleinput multiple-output (MIMO) configuration. Different types of three-dimensional (3-D) UAV trajectories are modeled based on an aeronautic smooth turn random mobility model (ST-RMM). Various types of antenna configurations are also considered in the model. This model is a 3-D geometry-based stochastic model (GBSM) founded on the 6G pervasive channel model (6GPC) to satisfy the requirements of 6G wireless communication systems. The generation method of large-scale parameters (LSPs) and small-scale parameters (SSPs) of the model is introduced, and the space-time cluster evolution process is modeled. Statistical properties including root-mean-square (RMS) delay spread, spacetime correlation function (STCF), stationary interval (SI), and channel capacity are also simulated and analyzed.