Design and implementation of NOMA subband scheduling towards larger bandwidth beyond LTE-A

Recent studies show that Non-Orthogonal Multiple Access (NOMA) can outperform conventional Orthogonal Multiple Access (OMA) in terms of both throughput and fairness. However, most of existing studies focus primarily on wideband scheduling without leveraging subband CQIs reported from users that reflect performance mismatch across difference frequency subbands. One challenge towards NOMA subband scheduling is the high complexity due to the need to jointly consider resource allocation for multiple user pairs across multiple subbands. In this paper, we propose a subband scheduling algorithm for NOMA based on the cross-entropy (CE) method to reduce computation complexity. The proposed solution utilizes subband CQIs reported from users that indicate SINR variations in the frequency domain to optimize the performance of all users across all resource blocks. We further implement subband scheduling for NOMA in the Vienna LTE-A downlink system-level simulator to substantiate the performance gain of subband scheduling against wideband scheduling on the well-tested evaluation platform.