Three-Dimensional Geometry-based Stochastic Model for Sub-Terahertz Air-to-Air UAV-MIMO channels

The integration of unmanned aerial vehicles (UAV) and terahertz (THz) technology can provide high data rate for air-to-air (A2A) communications. In this paper, a non-stationary geometric sub-THz multiple-input multiple-output (MIMO) channel model is proposed for UAV-A2A communications based on three-dimensional (3D) sphere model. To accurately describe the real A2A propagation environments, both scattering fading and reflection fading on the rough surface in sub-THz band are considered. Based on the proposed channel model, the space-time correlation function (STCF) and Doppler power spectrum density (PSD) have been derived and the impact of several important UAV-related parameters on the performance of channel characteristics in sub-THz band have been investigated and compared to that the millimeter wave (mm-wave) bands. Furthermore, the correctness of the proposed channel model has been verified and some useful observations are provided for the system design of sub-THz UAV-A2A MIMO communication systems.