Unified channel model for mobile radio systems with smart antennas

The definition of flat fading and frequency-selective fading channels is extended to low-rank and high-rank channels to include the angular domain. By physical reasoning a generic channel model is introduced incorporating directions of arrival and a set of parameters is given for its configuration. The time evolution of the scattering processes and directions of arrival is taken into account. Analytical expressions are derived for space-correlation coefficients and frequency-correlation coefficients. Spatial correlation decreases with increasing angular spread and decreasing angle of incidence, measured from a array broadside