Flexible User Mapping for Radio Resource Assignment in Advanced Satellite Payloads

Abstract

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 not necessarily by the corresponding beams yielding more power. 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. Thus, both beam capacity and load are adjusted to cope with the traffic demand. The specific locations of the user terminals play a major role, although their complexity does not increase as part of the proposed scheme. 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 considerable 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.