Using parabolic equation to predicate the propagation-loss of the rooftops of buildings in urban environments

Abstract

This paper concentrates on the propagation loss of the rooftops of buildings in urban environment by using parabolic equation. The radio communication is direct to each subscriber, the prediction of signal strength is most important in urban environments where subscriber density is high, and the buildings have a profound influence on the propagation. Because of complexity of radio propagation theoretical prediction in built-up areas, and propagation must take place through the buildings or over the rooftops with the field diffracted at the roofs down to street level, what's more, the primary propagation path lies over the tops of the buildings. Therefore, we have mainly taken into account the propagation-loss of the building rooftops. In the paper, the rows of buildings in urban areas are modeled as a series of perfectly conducting rectangular plateau with the purpose of simplifying the model to facilitate the solution. In addition, we proposed four kinds of typical urban models. As we all know, a highly attractive and effective model for the prediction of electromagnetic-wave propagation effects above the Earth's surface is the split-step parabolic-equation (SSPE) method, which it requires less computing effort than full elliptic methods. In this paper, we applied it to predicate the propagation-loss of the rooftops of buildings in urban environments. The comparison between the parabolic equation prediction and experimental data of the various models are presented, and the results are very promising. It is proved that the parabolic equation is a powerful and accurate method to calculate the electromagnetic wave propagation.