Geometry-Based UAV-MIMO Channel Modeling Assisted by Intelligent Reflecting Surface

A three dimensional (3-D) geometry-based channel model is proposed for intelligent reflecting surface (IRS)-assisted unmanned aerial vehicle (UAV) multiple-input multiple-output (MIMO) communication scenarios where the users are located on the edge of IRS service area. In order to reduce the interference between different IRS reflection units, we first construct an optimization problem about the statistical propagation phases of different IRS reflection units, and then derive the optimal statistical propagation phase by solving the designed optimization problem. Finally, we align the proposed statistical propagation phases of IRS with the stronger components to derive suboptimal IRS reflection phases. Using derived IRS reflection phases, the statistical properties are investigated. The numerical results show that the proposed IRS reflection phases can enhance the received signal strength and reduce the multipath fading effect. Also, it can be observed that when the number of IRS reflection units increases, the spatial correlation significantly decreases.