Iterative Filtering PAPR Reduction Method for OFDM Modulation in Fifth-Generation Cellular Networks

Abstract

Orthogonal Frequency Division Multiplexing (OFDM) is an ordinarily used waveform in the fifth generation (5G) cellular networks for uplink links. However, there is a prominent disadvantage in the form of a high peak-to-average power ratio (PAPR) which yields distortion in the timing signal generated at the output of the high-power amplifier (HPA). A new method called Iterative Filtering PAPR Reduction (IFP) has been suggested in this paper and maintains backward compatibility. The basic concept behind this algorithm is to obtain a filter based on a constant-envelope signal that is intimate to the original signal as far as power is concerned. The constant-envelope signal is then compared to the output between the product of the convolution of the original signal with the filter in question, allowing for the calculation of the impulse response of the filter. Such a process can be repeated several times with different filters to realize the best reduction in PAPR. The simulated results of the IFP method proved better performance in terms of PAPR reduction, Bit Error Rate (BER), and computational complexity requiring two iterations only. We can see a gain of 3.1dB in terms of PAPR reduction, 17dB in terms of BER, and a factor of 33 times in terms of computational complexity compared to the TR method. The Complementary Cumulative Complementary Density Function (CCDF) has assisted in measuring and improving the PAPR performance of the system. The theoretical analysis shows that a single iteration (NF=1) is sufficient, and the simulation results exposed in this paper show a gain of 3.1 dB in PAPR reduction.