On the Relation between Mobility and Rainfall Effects in Ku/Ka-band Line-of-Sight Land Mobile Satellite Channels: An Analytical Statistical Approach

The candidate frequency bands for the extension of the DVB-S2/RCS broadband satellite systems to fully support mobility are the Ku (12/14 GHz) and Ka (20/30 GHz). At these frequencies, rainfall is a significant propagation impairment which has to be taken into account together with other propagation effects due to mobility, such as multipath, shadowing and blockage. Experimental measurement campaigns conducted so far for Ku/Ka-band land mobile satellite (LMS) channels have mainly focused on the characterization of the mobility effects and have not considered any possible relation between the mobility and rainfall effects. However, recent limited work has indicated that these two fading sources are not independent. The present analysis represents a first approximation addressing this open problem. Emphasis is put on the line-of-sight (LOS) state of a Ku/Ka-band LMS channel, which can be modeled by the Ricean distribution and a high
K
-factor. A novel analytical model relating the Ricean
K
-factor with the rain fading effects is presented based on which, an analytical prediction model for the distribution of the Ricean
K
-factor is derived. The proposed analysis is flexible, can be applied on a global scale and incorporate the impact of several important operational, climatic and geometrical parameters of a mobile satellite system on its channel multipath behavior. Useful numerical results are provided, the need for further experimental verification data is pointed out and specific future planned work is also mentioned.