Optimizing Massive MIMO Design for Non Uniform Traffic in Broadband Telecommunication Satellites Networks

Abstract

There is a growing interest for satellites complementing the terrestrial networks for broadband access service provision. One of the key challenges is represented by the need to match the non uniform on-ground traffic distribution. This calls for exploiting large frequency reuse among the satellite beams and the adoption of interference mitigation through the use of precoding and/or efficient radio resource management techniques. In recent years, space technological developments have been making possible the implementation of active antennas operating at 20-30 GHz with a good level of efficiency thus opening up new perspectives in the flexible system and payload design. The presence of a large number of antenna radiating elements on-board the satellite stimulates the application of Massive Multiple Input Multiple Output (M-MIMO) techniques to satellite networks. In this paper, we extend previous work related to (pragmatic) M-MIMO adaptations for satellite broadband access networks and associated affordable complexity Radio Resource Management (RRM) algorithms. In particular, we cover the case of frequency colouring scheme and the optimization of the precoding in presence of non uniform traffic. We also enhance the system model to achieve more realistic and comprehensive analysis of the performance results by means of the generation of a generic spatial traffic distribution, a more accurate satellite antenna modelling for the RRM algorithm and emulating the channel estimation errors. A spatial derivation of the traffic request system satisfaction factor has been developed to enhance the analysis of the simulation results. All these enhancements are applied to the previously published non uniform synthetically generated traffic cases and to a more realistic study case corresponding to a geostationary (GEO) satellite covering Americas for which a novel system optimization methodology has been developed.