On the transfer matrix of a MIMO system

TL;DR

This paper presents a deterministic model for MIMO wireless channels derived from fundamental physics, providing insights into how propagation and coupling affect channel capacity and degrees of freedom.

Contribution

It introduces an ab-initio, physics-based model for MIMO channels using Maxwell's equations, scattering, and geometric perturbation theories.

Findings

Deep understanding of propagation effects on MIMO capacity

Quantitative analysis of array coupling impacts

Framework for predicting MIMO channel properties

Abstract

We develop a deterministic ab-initio model for the input-output relationship of a multiple-input multiple-output (MIMO) wireless channel, starting from the Maxwell equations combined with Ohm's Law. The main technical tools are scattering and geometric perturbation theories. The derived relationship can lead us to a deep understanding of how the propagation conditions and the coupling effects between the elements of multiple-element arrays affect the properties of a MIMO channel, e.g. its capacity and its number of degrees of freedom.