A physical-statistical model for land mobile satellite propagation in built-up areas

A physical-statistical model of land-mobile satellite propagation in built-up areas is derived from geometrical considerations and simple diffraction theory. The model has two components. The first predicts the probability with which a line-of-sight path exists between the mobile and the satellite. Some models predict the statistical fading characteristics of the received signal with the shadowing probability, Ps, as a parameter. This parameter is usually derived empirically by comparing measured results with the predictions and determining the value of the Ps which leads to the best fit between predictions and measurements. In the new model the Ps is related to physical parameters such as street widths and building height distributions. The second component of the model is a statistical prediction of the statistics of attenuation when a shadowed state is encountered, again related to physical parameters. The model allows predictions to be made for systems operated in areas where direct measurements are unavailable, or allows existing measurements to be scaled to apply to new parameter ranges. This is achieved with very low computational complexity and simple physical data.