Effects of down tilt antenna on the multipath propagation characteristics in the presence of an imperfect obstacle

Abstract

This paper presents the effects of transmitter antenna down tilting on the propagation channel characteristics applicable to mobile radio communications for PCS. The transmitting antenna is assumed with a directional radiation pattern. The total received signal strength is the vectorial summation of the various multipath signals (reflected, diffracted, and mixed, i.e., diffracted-reflected) in addition to the direct line-of-sight signal, if exists. The results include path loss, Doppler power spectrum, level crossing rates and delay characteristics. These characteristics provide valuable information on the area coverage, selection of optimum transmitter location, the choice of suitable data rates of the digital communication system.