Spatially Correlated 3-D HAP-MIMO Fading Channels

This paper proposes a three-dimensional (3-D) scattering model for multiple-input multiple-output (MIMO) land mobile stratospheric multipath-fading channels. Analytical and closed-form expressions for the spatial and temporal correlation functions between two arbitrary sub-channels are derived, assuming non-isotropic or isotropic scattering environments. This model can be used to estimate the required high altitude platform (HAP) antenna separation to achieve an uncorrelated HAP-MIMO channel matrix. Numerical calculations have been carried out to demonstrate theoretical derivations. The proposed model is useful to design, analyze and test future HAP-MIMO based 3G communication systems with line-of-sight (LOS) and non-line-of-sight (NLOS) components.