Quality of Service-Driven Overlapping Cooperative NOMA Scheme

Abstract

The rapid growth of connection density drives the next-generation wireless networks into ultra-large-scale systems with massive access demand. Therefore, massive access is crucial in next-generation multiple access design. Although nonorthogonal multiple access (NOMA) enhances user access and quality of service (QoS), NOMA and specifically cooperative NOMA (CNOMA) are limited in the literature by a trade-off between user access (i.e., number of users sharing the resources) from one side and successive interference cancellation (SIC) complexity and interference from the other side. To address this limitation, an overlapping CNOMA (O-CNOMA) scheme is proposed in this study. In multi-user O-CNOMA system, we formulate an optimization problem to maximize the celledge users' QoS satisfaction by controlling the overlapping cooperation among cell-center and cell-edge users. We utilize matching theory to address this issue. The proposed scheme's efficiency is confirmed through numerical results. Explicitly, O-CNOMA enables more flexible resource sharing and cooperation between users, outperforming the conventional CNOMA baselines in terms of average throughput, QoS satisfaction and SIC complexity. This makes O-CNOMA a promising scheme for practical implementation in 5G and beyond large-scale systems.