Flexible User Mapping for Radio Resource Assignment in Advanced Satellite Payloads

This work explores the flexible assignment of users to beams in order to match the non-uniform traffic demand in satellite systems, breaking the conventional cell boundaries and serving users potentially by non-dominant% \textcolor{blue}{[NA] not so accurate description } beams. The additional degree of freedom from the flexible beam-user mapping brings about a user-centric framework, with a two-step optimization process as a practical strategy. The smart beam-user mapping is jointly explored with adjustable bandwidth allocation per beam, and tested against different techniques for payloads with flexible radio resource allocation. Numerical results are obtained for various non-uniform traffic distributions to evaluate the performance of the solutions. The traffic profile across beams is shaped by the Dirichlet distribution, which can be conveniently parameterized, and makes simulations easily reproducible. Even with ideal conditions for the power allocation, both flexible beam-user mapping and adjustable power allocation similarly enhance the flexible assignment of the bandwidth on average. Results show that a smart pairing of users and beams provides significant advantages in highly asymmetric demand scenarios, with improvements up to 10\% and 30\% in terms of the offered and the minimum user rates, respectively, in hot-spot like cases with no impact on the user equipment.