PIC-based receiver structure for 5G downlink NOMA

Non-orthogonal multiple access (NOMA) is considered as a promising multiple access scheme for 5G downlink transmission. In this paper, we first review the existing downlink NOMA with successive interference cancellation (SIC) and then highlight some of the critical performance limiting factors related to SIC which can result in the performance degradation of NOMA. In order to alleviate the problems posed by SIC, we propose an alternate receiver structure for downlink NOMA based on parallel interference cancellation (PIC), along with some design consideration factors. The simulation results show that the proposed receiver outperforms that with SIC and hence is a promising receiver structure for future 5G downlink NOMA.