Efficient PAPR Reduction Scheme for OFDM-NOMA Systems Based on DSI & Precoding Methods

Orthogonal Frequency Division Multiplexing (OFDM)-based Non-Orthogonal Multiple Access (NOMA) systems are one of the promising technologies to be implemented in novel broadcasting and communication systems. One of the main challenges in OFDM-based systems is the high peak to average power ratio (PAPR), which degrades the system efficiency. Partial transmit sequence (PTS) and precoding approaches are among the best PAPR reduction schemes. The PAPR reduction in precoding methods is not as good as PTS-based ones. On the other hand, PTS-based methods are computationally complex and mostly degrade the system BER. In this paper, an efficient PAPR reduction scheme, based on the precoding and dummy sequence insertion (DSI) techniques, is proposed to overcome the previous limitations. Furthermore, a novel dummy sequence generation procedure is devised for the proposed method. We demonstrate that the developed scheme has a remarkably better PAPR reduction and BER performance than the precoding and PTS-based approaches. Moreover, it is computationally much less complex compared to the PTS methods.