Investigation into the Impact of Mutual Coupling on the Performance of a Multiuser MIMO System Employing Generalized Channel Inversion Technique

Feng Wang,Marek E Bialkowski,Konstanty Bialkowski

doi:10.1155/2011/965251

Abstract

In this paper, the performance of generalized channel inversion (GCI) technique for a multiuser MIMO system operating under antenna mutual coupling conditions is investigated. The investigation is performed via theoretical derivations and computer simulations. The theoretical derivations show that the presence of mutual coupling may result in an increased performance in terms of sum rate capacity. The simulation experiments confirm the theoretical findings in examples of three groups of numerical results. These results show that the existence of mutual coupling in an array antenna at base station (BS) results in an increased sum rate capacity when antenna interelement spacing at BS is smaller than 0.55 λ. Also it is shown that the presence of mutual coupling at mobile user (MS) terminals results in an increased sum rate capacity when antenna inter-element spacing at MSs is smaller than 0.4 λ. When mutual coupling is considered at both BS and MSs, the system configuration with antenna inter-element spacing equal to 0.45 λat BS and 0.4 λat MSs leads to the highest sum rate capacity.

Highlights

Multiple-input multiple-output (MIMO) technology has received enormous interest due to its potential in providing high and robust data transmission for wireless communications [1, 2]
With spatial correlations and mutual coupling taken into account, the effective wireless links between the base station (BS) and the K mobile user (MS) can be represented by an overall MIMO channel, which is given as
The sum rate capacity plots for the 2 × (3 × 6) multiuser MIMO system with mutual coupling taken into account show a M’-looking

Summary

Introduction

Multiple-input multiple-output (MIMO) technology has received enormous interest due to its potential in providing high and robust data transmission for wireless communications [1, 2]. Recent years have shown a significant shift of research attention from point-to-point to the multiuser MIMO systems [5], where a base station (BS) is communicating with a number of mobile stations (MSs). Physical limitations in mobile terminals as well as in BS force antenna elements in an array to be placed with a small interelement spacing This requirement is governed by compact MIMO transceivers especially on the user side. Mutual coupling has been taken into account while investigating performance of multiuser MIMO systems [13, 20]. The impact of antenna mutual coupling is investigated when a multiuser MIMO system employs a generalized channel inversion approach for its operation.

Signal and Channel Model

Mutual Coupling within an Array

Impact of Mutual Coupling on the Performance of Generalized Channel Inversion

Numerical Results

Conclusions