Coordinated satellite-terrestrial networks: A robust spectrum sharing perspective

The coordination between satellite communications and terrestrial mobile networks is promising to enable a globally ubiquitous broadband wireless coverage. It also provides an opportunity to share the spectrum between satellites and terrestrial networks, to alleviate the spectrum scarcity problem facing in both systems. Particularly in a coordinated satellite-terrestrial network (CSTN), the co-channel interference (CCI) should be carefully mitigated. Towards this end, this paper proposes a large-scale channel state information (CSI)-based robust coordination scheme. As the information exchange between satellite and terrestrial system is practically limited, and the overhead of each system for CSI acquisition is also limited, the proposed scheme is much more viable than existing results. In practice, the slowly-varying large-scale CSI can be obtained with a quite low cost, and the saddle point theory can be adopted to largely reduce the computational complexity of the proposed scheme. We finally show the simulation results to validate the superiority of the proposed scheme over existing methods.