Multipath propagation models for mobile line of sight conditions

This paper studies the behavior of a multipath channel for suburban and semi-rural areas in which line of sight (LOS) or near LOS exists between the transmitter and receiver. The objective is to characterize the behavior of a broadband channel for such areas. The amplitudes and delay spread of a multipath model for such an environment are studied, based on a theoretical analysis of scattering from finite flat surfaces which model building walls. It is found that, close to a building, the reflection produces a severe degradation but, beyond a certain distance, the reflection decreases rapidly with distance. These findings, explain previously reported phenomena of very large line of sight signal fluctuations and have been confirmed with two propagation measurement trials.