Modeling and estimation of the direction-delay power spectrum of the propagation channel

In this contribution, a multi-variate probability density function (pdf) is derived and used to describe the normalized direction-(i.e. azimuth and elevation)-delay power spectral density of individual dispersed components in the response of the propagation channel. This pdf maximizes the entropy under the constraint that its first and second moments are specified. We use a SAGE algorithm, as an approximation of the maximum- likelihood method, to estimate the parameters of the component direction-delay power spectral densities from measurement data. The experimental results show that the proposed pdf and the SAGE algorithm form altogether an effective tool to characterize direction-delay dispersion in the propagation channel.