Spectrum Efficient Resource Management for Multi-Carrier-Based NOMA Networks: A Graph-Based Method

This letter investigates the spectrum efficient resource management problem (SERMP) for non-orthogonal multiple access-based uplink networks. Specifically, we take the decoding threshold of successive interference cancellation into account and formulate the SERMP as a sum-rate maximization problem by jointly considering the user pairing, channel assignment, and power control. For tackling this hard problem, we first analytically get the optimal transmit power for each user pair with given channel assignments. Afterward, we tactfully transform the primal problem into a maximum weighted independent set issue in graph theory, based on which we devise a low-complexity resource allocation algorithm. Finally, simulation results exhibit the performance improvement of our algorithm against other schemes in terms of data rate and number of supported users.