Correlations and channel capacities for multi-polarized MIMO systems

The performance of multiple-input multiple-output MIMO systems strongly depends on the correlation between antenna elements. In this paper, we propose a model for calculating the correlation between multi-polarized Rayleigh fading MIMO channels, which takes into account not only the gain patterns of both transmitting and receiving antennas, but also the polarization matrix of the propagation channel, array configurations and joint three-dimensional power angular spectrum on both transmitting and receiving side. The proposed model is then used to investigate the channel capacity for various 3×3 MIMO configurations in different propagation environments. It is found that when the antenna array size is limited, angular spread and cross-polarization ratio is small, the ergodic capacity of a multi-polarized configuration performs better than that of a single-polarized configuration.