Modeling of the Land Mobile Satellite Channel considering the Terminal’s Driving Direction

A precise characterization of the Land Mobile Satellite (LMS) channel, that is, the channel between a satellite and a mobile terminal, is of crucial importance while designing a satellite-based communication system. State-of-the-art statistical LMS channel models offer the advantage of requiring only a few input parameters, which include the environment type and the elevation angle of the satellite. However, the azimuth angle relative to the driving direction of the mobile terminal is usually ignored, as its proper modeling requires either an extensive measurement campaign or a significant effort from the user, as a precise geometrical description of the scenario is required. In this contribution we show that the impact of the driving direction on the channel statistics is not negligible and requires to be modeled explicitly. Moreover, we propose a statistical LMS channel model whose parameters are obtained via an image-based state estimation method. The image-based method is verified by a comparison with measured radio frequency signal levels. The proposed method allows obtaining a complete statistical description of the channel for arbitrary elevation and azimuth angles

Estimation of fading parameter correlation for modeling the land mobile satellite channel

This paper addresses the correlation of fading signal parameters for dual-satellite land mobile satellite (LMS) channels. We use Loo's model to describe the slow and fast variations that occur due to varying shadowing conditions and multipath fading, respectively. Loo's parameters (mean power of direct signal component, standard deviaton of direct signal component, and average multipath power) are estimated segment-by-segment from fading signals of two simultaneously measured geostationary satellites using a curve-fitting approach. The parameter correlation between the signals of the two satellites is investigated. A significant correlation is found in the mean power of the direct signal components in some environments, when both satellites are shadowed or blocked by obstacles