A User Pairing Technique for Mixed Traffic Types in Downlink NOMA

This paper proposes a resource allocation technique for downlink non-orthogonal multiple access network (NOMA) under mixed real-time (RT) and best effort (BE) user traffic. To achieve quality of service (QoS) requirement of real-time users and to accomplish fairness among BE users, we propose a user pairing technique along with a water-filling solution with lower bound constraint for BE users. The proposed algorithm fulfills the QoS requirements of real-time users while satisfying fairness among BE users. Simulation results show that our proposed algorithm performs better than baseline techniques in terms of mean data rate, QoS achievement percentage of RT users, and fairness for BE users.