Non-orthogonal access with SIC in cellular downlink for user fairness enhancement

Abstract

This paper investigates the enhancement of cell-edge user throughput by using non-orthogonal access with a successive interference canceller (SIC) in the cellular downlink compared to orthogonal access, which is widely used in 3.9 and 4G mobile communication systems. Since both the total user throughput and cell-edge user throughput are important in a real system, we compare the cell-edge user throughput while subject to the same total user throughput. The optimum resource allocation in terms of bandwidth and transmission power for each user is assumed for the respective access schemes based on the instantaneous channel conditions. The evaluation results show that non-orthogonal access with a SIC significantly enhances the cell-edge user throughput (thus user fairness) compared to orthogonal access while achieving the same total user throughput in the context of the cellular downlink, which can yield some insights regarding the direction of the wireless access scheme for the systems beyond IMT-Advanced.