High Resolution Spatiotemporal Characterization of Electric Field Polarization for Indoor Wireless Environments

Abstract

The effects of the electric field polarization on the received power are investigated based on high resolution measurements of the indoor wireless channel. The results presented here were obtained using a channel sounding testbed, which was specially designed to study the radio propagation in the 5-6 GHz frequency band with high resolution in terms of angle-of-arrival (AOA) and time-of-arrival (TOA). Measurements were made at different indoor locations and the influence of the receiver surroundings on polarization cross-coupling was analyzed as a function of the azimuthal and elevation AOA. Significant cross-coupling was measured in locations where multi-paths arrive with oblique AOA with respect to the horizontal plane (thetas=90deg). The cross-polarization was characterized with high resolution in azimuth and elevation, which enabled the study of the spatial distribution of depolarized multipaths. The amount of power due to cross-polarized multipaths was estimated for a vertically polarized transmitter antenna located in different indoor environments. The advantages of using multi-element antennas and polarization diversity were made evident, as well as the importance of the relative location of transmitter and receiver and the 3-D distribution of the nearest scatterers.