Multiple Gateway Precoding with Per Feed Power Constraints for Multibeam Satellite Systems

Multibeam satellite systems have been recently studied in order to provide broadband services to their coverage area by employing fractional frequency reuse pattern. Towards a more spectrally efficient system, the designer can resort to full frequency reuse among beams with on-ground extra signal processing as a precoding or detecting scheme for limiting the interbeam interference. These techniques have shown great potential in the multibeam system architecture. However, feeding all these data from a single gateway is not feasible based on the current frequency bandwidth resources utilized on the feeder link. In this paper, the focus is set on the forward link of a multibeam satellite system where full frequency reuse among beams with linear precoding technique is considered. In this context, we investigate a multiple gateway scenario where each gateway is serving a cluster of adjacent beams. Note that with a multiple gateway architecture, the feeder link spectral resources can be shared by all the gateways since they use directive antennas so that interference is minimized and the spectral efficieny of the feeder link system is increased. We present a novel multiple gateway Zero Forcing (ZF) precoder design which mitigates both the inter and intra-cluster interference. The provided simulation results quantify the performance gain obtained by our method.