On the Spectral Efficiency and Security Enhancements of NOMA Assisted Multicast Multicast-Unicast Streaming
Abstract: This paper considers the application of non non-orthogonal orthogonal multiple access (NOMA) to a multi-user user network with mixed multicasting and unicasting traffic. The proposed design of beamforming and power allocation ensures that the unicasting performance is improved while maintaining the reception reliability of multicasting. Both analytical and simulation results are provided to demonstrate that the use se of the NOMA assisted multicast multicast-unicast unicast scheme yields a significant improvement in spectral efficiency compared with orthogonal multiple access (OMA) schemes which realize multicasting and unicasting services separately. Since unicast messages are broadc broadcast ast to all the users, how the use of NOMA can prevent those multicast receivers intercepting the unicasting messages is also investigated, where it is shown that the secrecy unicasting rate achieved by NOMA is always larger than or equal to that of OMA. Si Simulation mulation results are provided to verify the developed analytical results and demonstrate the superior performance of the proposed NOMA scheme.