On land mobile satellite navigation performance degraded by multipath reception

In this paper simulation results of DLR’s ultra-wideband land mobile satellite (LMS) multipath channel model are presented. The goal is the evaluation of GNSS performance in the rail environment. For this safety of life (SOL) application an urban railway was identified as the most critical scenario. The channel model is based on a measurement campaign of the land mobile multipath channel performed in 2002. From this data a model was derived that is synthesising the measured channel impulse response. It allows the realistic simulation of the multipath channel by approximating every single reflection. This model includes time variant reflectors approaching and receding in dependency of the azimuth and elevation of the satellite. All the signal processing had been realised independently of the transmitted signal. Therefore the usability for both, navigation systems GPS as well as GALILEO is given.