Feeder Link Precoding for Future Broadcasting Services

5G systems are becoming a reality and the evolution towards Beyond 5G (B5G) and 6G systems is already being defined, also to cope with the ever increasing capacity demanded by on-ground users. This will pose challenging requirements on the feeder link of future satellite systems, which risks to become a bottleneck for the overall system performance. In this paper, we propose a novel architecture of linear precoding for the feeder link of a broadcast satellite system operating with full frequency reuse to significantly enhance the achievable capacity. The architecture has been simulated and tested in a challenging multi-frequency scenario, where Ku, Ka, Q/V, and W band have been considered for transmission. The numerical performance analysis and the open issues related to the practical realisation of the proposed architecture are also thoroughly discussed.