MIMO Channel Capacities in Presence of Polarization Diversity with and without Line-of-Sight Path

摘要

As a result of the extensively desired high data transmission rate and reliability in wireless communication systems, an exploitation of multiple-input multiple-output (MIMO) systems is one of the most promising candidates under the condition of rich multipath environments. However, MIMO channel capacity is limited by the subchannel correlations in scattering environments. Then for reducing or eliminating the spatial correlation effects, the polarized antenna arrays at both transmitters and receivers are employed. In this paper, a geometric scattering channel model is used to demonstrate the communication performance while utilizing the polarized antenna arrays. Moreover, this model is obviously characterized by antenna configurations and propagation environments. Antenna configurations consist of antenna type and antenna geometry. Propagation environments consist of solid angle diffusion (angle spread), scattering property and number of channels. In this paper, we examine a uniform linear array with omidirectional antennas and dipole antennas. We investigate also the channel capacity of single, dual and triple polarized dipole antennas in presence and absence of line-of-sight path and its effects on 2×2 and 3×3 MIMO systems for narrow transmission bandwidth. The simulation results show that, with polarization diversity techniques, the MIMO channel matrix has high rank even if the line of sight path is present. This polarization diversity technique should be applied o point-to-point communication systems such as Inter Base Mobile Station Communication, Mobile Satellite communication, etc.