Analysis on multipath shape factors of air-to-ground radio communication channels

This paper first presents an extension of a notable three dimensional (3D) channel model for air-to-ground (A2G) radio propagation environments, from the plain distribution of angular energy to the quantization of multipath shape factors (SFs). Next, the paper presents a comprehensive analysis on the characteristics of multipath SFs for A2G radio propagation environments observed at both ends of the link. The analysis include the impact of various physical channel parameters on angular spread, true standard deviation, angular constriction, and direction of maximum fading. These SFs are obtained by exploiting the analytical and empirical results available in the literature for the distribution of energy in 3D angular space. Finally, a mechanism for classification of A2G propagation environments into taxiing, en-route, and take-off scenarios on the basis of SFs is presented.