A 3D correlation model for MIMO non-isotropic scattering with arbitrary antenna arrays

We introduce a multiple-input multiple-output (MIMO) space-time-frequency wireless channel model for the wave propagation in three-dimensional (3D) space. The cross-correlation function (CCF) between two subchannels of the MIMO communication system is decomposed into some non-negative functions. These functions are expressed in terms of a selection of channel parameters, such as the carrier frequencies, the delay profile, the path-loss exponent, the softness factor, θ, the non-uniform distribution of directions of arrival and departure, array geometries, and the mobile speed. We introduce a class of distributions for the elevation angle (EA) spreads as a basis such that any arbitrary (isotropic or non-isotropic) EA distribution can be represented by a convex linear combination of this class. The corresponding term of the CCF of the 3D-MIMO model for any EA distribution equals to the same linear combination of the basic CCF terms associated to the class. This 3D-MIMO model formulates the CCF as a function the spacial separation of antennas, time, and carrier frequencies in terms of physical channel parameters such as mobile speed, delay profile and distribution of scavengers around mobile and base stations.