Simulation of the Effects of Different Urban Environments on Land Mobile Satellite Systems Using Digital Elevation Models and Building Databases

Effects of four urban areas of the city of Rio de Janeiro, Brazil, on the propagation channels of three land mobile satellite systems are analyzed using computer simulation. Initially, a digital elevation model, building databases, and a vegetation model are processed to generate azimuth-elevation maps of three path states (clear, shadowed, and blocked) for a large number of users. The simulation procedure combines the maps with signal models for the three states and a satellite orbit predictor. The probabilities of different path-state mixtures, as well as the cumulative distribution functions of fades in several types of received signals resulting from the application of different mitigation techniques, are presented and discussed.