On building modeling for multiple diffraction analysis in urban environments considering spherical-wave incidence

A study of the influence of building modeling when predicting the signal attenuation due to over-rooftop multiple diffraction in urban environments is presented. A straightforward formulation expressed in terms of Uniform Theory of Diffraction (UTD) coefficients is used for the above-mentioned analysis assuming a spherical-wave incidence over the array of buildings and considering the latter modeled as series of different representations such as knife edges, double knife edges, wedges and rectangular sections. The results clearly indicate the importance of an appropriate building modeling in obtaining realistic path-loss predictions in urban environments when multiple diffraction has to be considered.