A Novel Multiuser HAP-MIMO Channel Model Based on Birth-Death Process

This paper proposes a three-dimensional (3-D) multiuser channel model for stratospheric multipath-fading channel. The birth-death process is used to model the non-stationary properties that scatterers "appear" and "disappear" on the array axes. The spatial correlation of multiuser High Altitude Platform (HAP) multiple-input multiple-output (MIMO) channel is investigated in this paper. This model can be used to estimate the acquired antenna separation at Stratospheric Base Station (SBS) and user to achieve uncorrelated channel matrix between two adjacent users. Numerical results show that the proposed model is able to capture characteristics as observed in measurements.