Depolarization effects of radio wave propagation in various land built-up environments

Abstract

Detailed analysis of spatial-temporal variations of the polarized characteristics of the elliptically polarized radio wave propagating in various built-up environments is presented. Classical methods of definition of polarized parameters of homogeneous monochromatic plane waves arriving at the receiver antenna from various directions in free space, were adapted for the propagation scenarios occurring in the land built-up environments, where the complicated stochastic variations of wave polarization parameters have been observed experimentally and when the canonical methods become to be not effective. Based on the 3-D classical presentation of the geometrical parameters of the polarized ellipse and of the Stocks parameters usually used in derivations, we analyzed the co-polarized and cross-polarized components of the wave intensity in the vertical and horizontal plane of the polarization ellipse, respectively. Their relations with the main parameters and characteristics of the built-up terrain were derived allowing us to estimate the angle of wave depolarization and the polarization loss effects. Numerical computations are carried out for specific topographies of rural, mixed residential, sub-urban, and urban areas. The obtained results show that the buildings' heights, density of buildings and the elevations of the base station (BS) antennas with respect to buildings placed in the areas of communication, can sufficiently increase the effects of polarization discrimination (or mismatch) defined by the depolarization angle and the depolarization loss of the elliptically polarized radio waves and the additional energy loss and fading of the total wave field.