Design of Cooperative Non-Orthogonal Non Orthogonal Multicast Cognitive Multiple Access for 5G Systems: User Scheduling and Performance Analysis
Abstract: Non-orthogonal orthogonal multiple access (NOMA) is emerging as a promising, yet challenging, multiple access technology to improve spectrum utilization for the fifth generation (5G) wireless networks. In this paper, the application of NOMA to multicast cognitive radio networks (termed as MCR-NOMA) MCR NOMA) is investigated. A dynamic cooperative MCR-NOMA MCR NOMA scheme is proposed, where the mu multicast secondary users serve as relays to improve the performance of both primary and secondary networks. Based on the available channel state information (CSI), three different secondary user scheduling strategies for the cooperative MCR-NOMA MCR scheme are presented. To evaluate the system performance, we derive the closed-form form expressions of the outage probability and diversity order for both networks. Furthermore, we introduce a new metric, referred to as mutual outage probability to characterize the cooperation cooperation benefit compared to non-cooperative non MCR-NOMA NOMA scheme. Simulation results demonstrate significant performance gains are obtained for both networks, thanks to the use of our proposed cooperative MCR-NOMA NOMA scheme. It is also demonstrated that higher spat spatial diversity order can be achieved by opportunistically utilizing the CSI available for the secondary user scheduling.