System design and performance evaluation for power domain non-orthogonal multiple access

To meet the 5G requirements on spectral efficiency and connection density, non-orthogonal multiple access (NMA) is becoming an important candidate technology. This paper focuses on power-domain NMA (PNMA) due to the relatively low design complexity and standardization impact. In PNMA, the data of more than one user equipment (UE) are superposed with different transmission power setting at the transmitter, and are separated by utilizing interference cancellation at the receiver. The theoretical performance of PNMA has been shown in some previous research. In this paper, we gives our proposals on PNMA practical system design aspects including base station (BS) scheduling, UE receiver implementation and network signaling, aiming to seek for good trade-off between overall performance and complexity. System-level simulations validate that compared to orthogonal multiple access (OMA), PNMA with our proposed scheduling algorithm can bring 14.16% and 23.88% gain in cell average spectral efficiency (SE) and cell edge SE respectively, as well as improve the number of connected UEs by 55%.