Efficient and Dynamic Fractional Frequency Reuse for Downlink Non-Orthogonal Multiple Access

This paper investigates inter-cell interference mitigation of non-orthogonal multiple access (NOMA) in the cellular downlink. A novel adaptive power and frequency resource allocation algorithm in the NOMA system is proposed for performance enhancement. The objective of the algorithm is to improve both the average cell throughput and cell-edge throughput through adaptive resource allocation in the power and frequency domains. The proposed algorithm improves the cell-edge throughput by providing better protection against inter-cell interference in the power domain while increasing the average cell throughput by providing more resources in the frequency domain. Numerical results show that the proposed algorithm yields significant improvements in the cell average throughput and cell-edge throughput by reducing the interference for cell-edge users and expanding the bandwidth for cell interior users.