A Matching-Theoretic Approach to User-Association and Channel Assignment in Downlink Multi-Cell NOMA Networks

In this paper, the problem of stable user-association and channel assignment in downlink multi-cell NOMA networks is studied. Specifically, the aim is to match network users to channels available at each base-station, while taking into account negative network externality resulting from inter-user interference. Specifically, a solution procedure to determine the optimal power allocation for proportional-fairness SINR-based maximization is devised, which is used to determine the preferences of different user sets over the available channels of each base-station, and the preferences of base-stations for each network user. After that, two centralized polynomial-time complexity stable matching algorithms based on the many-to-one student-project allocation matching problem are proposed to associate users with base-stations and assign channels to them. Simulation results are presented to validate the efficacy of the proposed algorithms, and compare them with a centralized joint user-association, channel assignment, and power allocation scheme, where it has been shown that the proposed algorithms yield comparable SINR per user as well as efficiently assign channels to cell-edge users, while achieving proportional-fairness.