A New Method for Reducing PAPR in OFDM System Based on GreenOFDM

Abstract

In wireless communications research and application, Orthogonal Frequency Division Multiplexing (OFDM) has been established as a key PHY layer enabling technology (e.g., in both 4G and 5G cellular network standards). However, the Peak-to-Average-Ratio (PAPR) problem can lower system performance and has been under intense research in recent years. The trade-off between high PAPR reduction factor and high signal redundancy and/or computational complexity has not been sufficiently addressed by many works on this problem, and some approaches with state-of-the-art PAPR reduction performance suffer from high bit redundancy or have a higher complexity. So a method based on selected mapping orthogonal frequency division multiplexing modulation (SLM-OFDM) that generates (N2/4) symbol candidates using N inverse Fast Fourier Transform (FFT) is presented which is called GreenOFDM. In this paper, we propose an improved method based on GreenOFDM, We add a weighting factor α when generating the symbol candidates, and then select the symbol of the minimum PAPR for transmission. Computer simulation shows that this method is better than the original GreenOFDM When we choose the right weighting factor α. This not only gets lower signal redundancy, but also has lower complexity and simulation results show that the signal PAPR is significantly reduced.