Spatial Correlation and Ergodic Capacity of MIMO Channel in Reverberation Chamber

Xiaoming Chen

doi:10.1155/2012/939104

Abstract

It has previously been shown that a reverberation chamber can conveniently be used to measure ergodic multiple-input multiple-output (MIMO) capacity for over-the-air (OTA) tests. However, the MIMO channel in the reverberation chamber has not been fully studied before. In this paper, the spatial correlation of the MIMO channel in the chamber is studied by comparing the measured channel with two popular MIMO channel models. It is shown that the models can accurately predict the ergodic MIMO capacity of the channel in the reverberation chamber, but not the outage capacity (especially at high signal-to-noise regime). It is verified that the capacity estimation error is due to the fact that the measured MIMO channel in the chamber does not satisfy multivariate normality (MVN), which causes the capacity error increases additively with MIMO size and multiplicatively with signal-to-noise (SNR).

Highlights

Multiple-input multiple-output (MIMO) systems have drawn considerable popularity, over the past decade, due to their performance-enhancement capability in multipath environments [1]
The MIMO channel in a reverberation chamber is studied by comparing the measurements with different channel models
It is found that both models have the same performance in terms of capacity estimation for the reverberation chamber measurements and that all of them can well predict the ergodic capacity up to six antenna elements with only slight overestimation at high-signal-to-noise ratio (SNR) regime

Summary

Introduction

Multiple-input multiple-output (MIMO) systems have drawn considerable popularity, over the past decade, due to their performance-enhancement capability in multipath environments [1]. There exist other sophisticated models, it is well known that the full-correlation model offers the best accuracy at the expanse of the most complexity We include both Kronecker model and the full-correlation model in this paper. It is found that both models have the same performance in terms of capacity estimation, which is a bit surprising Instead of capacity underestimations as indicated by real-life measurements [4], the present paper shows that Kronecker model tends to overestimate capacities based on measurements in a reverberation chamber.

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Conclusion