Optimal Multi-Stage Clipping for Impulsive Noise Mitigation in OFDM-NOMA Systems

Non-orthogonal multiple access (NOMA) was recently proposed as a viable technology and a strong candidate for future wireless communications. On the other hand, numerous emerging technologies present environments which are characterized by the presence of impulsive electromagnetic interference, known as impulsive noise. This noise can significantly affect the reliability of the communication link. Therefore, given the distinct characteristics of NOMA, this article proposes a multistage clipping approach for the mitigation of impulsive noise in orthogonal frequency division multiplexing (OFDM)-NOMA systems. Moreover, for each stage, considering the weighted combination criterion, we proceed to derive the optimum clipping threshold. Provided Monte-Carlo simulation results prove that our proposed approach outperforms the conventional singlestage clipping applied to NOMA and that the proposed optimum threshold significantly reduces the detrimental effects of impulsive noise in OFDM-NOMA systems where a gain of at least 10dB compared to the conventional clipping approach case is achieved by the successive interference cancellation (SIC) user.