MIMO Channel Correlation in General Scattering Environments

TL;DR

This paper introduces a comprehensive analytical model for MIMO channel correlation in complex scattering environments, capturing interdependencies between angles and improving upon traditional models like Kronecker.

Contribution

The paper develops a bi-angular power distribution-based model that accounts for non-separable scattering environments and inter-angle covariance, extending beyond the Kronecker model.

Findings

Kronecker model is accurate for single scattering clusters.

Kronecker overestimates performance with multiple scattering clusters.

New model captures interdependencies in complex environments.

Abstract

This paper presents an analytical model for the fading channel correlation in general scattering environments. In contrast to the existing correlation models, our new approach treats the scattering environment as non-separable and it is modeled using a bi-angular power distribution. The bi-angular power distribution is parameterized by the mean departure and arrival angles, angular spreads of the univariate angular power distributions at the transmitter and receiver apertures, and a third parameter, the covariance between transmit and receive angles which captures the statistical interdependency between angular power distributions at the transmitter and receiver apertures. When this third parameter is zero, this new model reduces to the well known "Kronecker" model. Using the proposed model, we show that Kronecker model is a good approximation to the actual channel when the scattering channel consists of a single scattering cluster. In the presence of multiple remote scattering clusters we show that Kronecker model over estimates the performance by artificially increasing the number of multipaths in the channel.