Railway satellite channel at Ku band and above: Composite dynamic modeling for the design of fade mitigation techniques

摘要

Past studies on the railway satellite channel (RSC) at Ku band and above consider exclusively the attenuation coming from the metal power arches (Pas) along the railway route, producing significant though deterministic periodical fast fading. Nevertheless, limited attention has been given to model tropospheric effects on the RSC. The present paper takes a more comprehensive view of the RSC by introducing a novel stochastic dynamic model of rain fading in mobile satellite systems on top of the diffraction because of Pas. The proposed approach builds upon well-established research on rain attenuation time series synthesizers employing stochastic differential equations. It is shown that this propagation tool may provide significant aid, in general, in mobile satellite system simulations and in the design of fade mitigation techniques (FMTs), particularly aiming at the railway scenario. The tool enables the generation of fade events, fade duration statistics, rain attenuation power spectrum and predicting the necessary FMT control loop margin. This is particularly useful for the RSC because most of the proposed FMTs focusing on Pas are not appropriate for compensating atmospheric fading.