System concept for a digital repeater intended for a future generation of german telecommunication satellites

Abstract

The derivation of a system concept for the digital multi‐service repeater starts from evaluating the mission profile and the antenna concept elaborated so far. Furthermore, the repeater concept is shaped by Ka‐band propagation conditions, the kind of integration of a down‐link TV‐distribution service into the prevailing multi‐beam communications mode and readily available digital technologies. It is intended to embark on a completely regenerative approach using a unified switching concept for all services accompanied by a large amount of rearrangement functions in the foreground. An attempt is made to define those network control functions and procedures to be located on‐board exploiting the fact that the repeater already acts as a central switching node. The discussion of on‐board digital technologies concentrates upon a multicarrier demodulator concept and a candidate solution for the baseband switch. One general boundary condition is pronounced due to uncertainties about the actual traffic scenario in the future: all repeater resources must be accessible for the most important of the services considered, i.e. the provision of satellite business services.