Capacity of MIMO System Using Polarimetric Antenna Elements

Abstract

Exploitation of polarization for MIMO system is a promising approach to increase multiple parallel channels, particularly for space-limited mobile and base-stations. For this purpose, the use of polarimetric antenna elements has been studied by both theoretical studies and experiment [1]-[4]. The studies, however, present different conclusion on the number of possible independent parallel channels from polarization diversity. In this paper, we study the use of polarimetric antennas under different scattering environments by using a three dimensional (3D) polarized channel modelling in which the Fisher-Bingham (FB5) distribution was used to model direction of scatterers in 3D space. We found that due to a significant correlation between electric and magnetic dipoles, only four independent channels are obtained in fully scattering condition and that in order to achieve full capacity, a certain separation between them is required. Our results can be used for optimisation of array antenna design using polarimetric antenna elements.