A hybrid technique for the PAPR reduction of NOMA waveform

Abstract

Non-orthogonal multiple access (NOMA) is a great contender for future cellular modulation due to its desirable properties like massive connectivity, high data rate transmission, and high spectral efficiency. However, its peak-to-average power ratio (PAPR) is significant, which becomes a significant disadvantage for the efficient operability of the NOMA waveform compared to current techniques. Several PAPR reduction algorithms like selective mapping (SLM), partial transmission sequence (PTS), and companding techniques have been proposed to lower the PAPR of multicarrier waveforms (MCWs). PTS reduces the PAPR but has high complexity. On the other hand, SLM has a less complex framework, but its PAPR performance is not as efficient as PTS. Companding methods reduce the PAPR by compressing the signals at the transmitter, which unfortunately reduces the dynamic range of the signal. In this work, we propose a hybrid algorithm (SLM + PTS) with a companding method for the first time for the NOMA waveform, which efficiently reduces the PAPR with low computational complexity. Furthermore, we compare the performances of a host of candidate algorithms like SLM, PTS, hybrid (SLM + PTS), hybrid + A law (SLM-PTS-A law), and hybrid + Mu law (SLM-PTS-Mu law). The results of the experiments show that the hybrid + Mu law did a better job than the existing PAPR reduction algorithms.

Exploring and Analyzing a Hybrid PAPR Reduction Method for OFDM Optimization

“…In order to determine the ideal phase sequence that minimizes PAPR, the algorithm does a thorough search over various phase factor combinations for each partition. While this method successfully lowers PAPR, it can be computationally taxing to perform an exhaustive search, especially when there are more sub-blocks and partitions [8]. As a result, in real-world applications, the objective of PAPR reduction and processing complexity must be balanced.…”

PAPR reduction using SLM-PTS-CT hybrid PAPR method for optical NOMA waveform

“…The suggested SI-free transmission strategy performs well in terms of low BER degradations over the AWGN and Rayleigh fading channels, according to simulation findings. Probability of SI error detection, reduced computational burden, and enhanced PAPR reductions of the OFDM signals The authors of [ 27 ] introduced a hybrid approach (SLM and PTS) with a complementing mechanism that effectively lowers the PAPR with little computing cost. Additionally, we contrast the performance evaluations of several potential algorithms, including SLM, PTS, hybrid (SLM + PTS), hybrid + A law (SLM-PTS-A law), and hybrid + Mu law (SLM-PTS-Mu law).…”