Resource Allocation for NOMA-enabled Satellite- Terrestrial Networks

With the increasing demands for communications in the remote areas without terrestrial networks, satellite networks have become a promising paradigm. However, it is an issue of satisfying demands with limited resources of satellites. In this paper, considering a NOMA-enabled satellite-terrestrial network, we propose a resource allocation strategy to maximize spectral efficiency of satellites. Firstly, we formulate the optimization problem as a mixed integer nonlinear problem. Due to its non-convexity, we transform the non-convex problem into three subproblems. Then, we propose subcarrier allocation algorithm and Lagrange quick iterative water filling algorithm with low complexity to solve the subproblems. Finally, the numerical results demonstrate that the proposed low-complexity scheme is close to the optimal solution obtained by the exhaustive algorithm.