SPECTRAL CLUSTERING FOR BEAM-FREE SATELLITE COMMUNICATIONS

This paper introduces the notion of beam-free satellite systems and it investigates different scheduling algorithms for this architecture. Attending to the current satellite gateway cloudification, this paper assumes that users from different beams can be scheduled over the same frame. Indeed, considering full frequency reuse among beams and on ground precoding, we show that whenever the scheduler is able to freely group users independently of their beam location, large attainable rates are obtained. In addition, we also consider that the gateway is able to select a number of simultaneous transmissions which leads to a substantial sum-rate increase. A scheduling scheme based on spectral clustering is proposed and it shows a higher performance compared to other state-of-the-art alternatives. In addition, our method is able to deal with different user terminal traffic classes. Based on the numerical results obtained considering a close-to-real multibeam satellite pattern, we point out that the current per-beam scheduling process is an inefficient network management for multi-beam satellite systems using precoding.