Interference coordination for the return link of a multibeam satellite system

Abstract

Future internet demands are being increased dramatically year by year. Terrestrial systems are unable to satisfy these demands in all geographical areas and thus broadband access by satellite is a key service provision platform. Considering the traffic demands, the raw capacity should approach a Terabit/s by 2020 to meet these demands. The satellite communications network will be a star-based topology, where User Terminals (UT) from multiple beams communicate via central Gateway Earth Stations (GES). The return link from UT to satellite will use DVB-RCS2 Multi-Frequency Time Division Multiple Access (MF-TDMA) transmission scheme in Ka band (30GHz), while the return feeder link from satellite to GES in Q band (40 GHz). Due to generation of large number of narrow user beams, the interference starts becoming a limiting factor in the system's dimensioning. Herein, interference coordination schemes, borrowed from terrestrial cellular systems, are examined in terms of applicability and C/I performance. In addition, an algorithm for dynamic interference coordination is proposed to schedule the transmissions of the users in time-frequency domain of the return link, aiming to improve the C/I. The performance of these schemes and the proposed algorithm is assessed over a 302 user beams satellite system with practical antenna radiation patterns.