Distributed Power and Carrier Allocation in Multibeam Satellite Uplink with Individual SINR Constraints

Current multibeam satellite systems perform centralized power and carrier allocation assuming a Multi-Frequency Time Division Multiple Access (MF-TDMA) scheme with fixed regular frequency reuse. This approach is not optimal when individual SINR constraints are to be met. In this paper, we formulate the problem of joint power and carrier allocation allowing non-regular frequency reuse. This setting will increase the interference levels but in turn will allow a more efficient use of the power increasing the spectral efficiency. We focus on a distributed formulation of the problem and compare it with the conventional power balancing solution. Numerical results show that the centralized power balancing approach performs better for high SINR constraints, balancing the co-channel interference among all the users and beams. Conversely, the decentralized approach optimizes the satellite terminals' self-interest deteriorating SINR of high loaded beams resulting in worse performance for highly loaded beams.