Reduction of Peak to Average Power Ratio (PAPR) in Orthogonal Frequency Division Multiplexing (OFDM): A Novel Approach Based on Clipping and Amplification

Abstract

Reduction of Peak to Average Power Ratio (PAPR) in Orthogonal Frequency Division Multiplexing (OFDM) is investigated here. Clipping can be performed in two ways– one is to clip the complex envelopes of OFDM signal and the other is to clip the Inphase (I-signal) and Quadrature phase (Q-signal) independently. The detailed investigation concerning the PAPR reduction and Complementary Cumulative Distribution Function (CCDF) of both the techniques is made. A novel approach based on clipping and amplification is introduced as a mean for reducing PAPR in OFDM signal. Our Proposed scheme combines the effect of clipping the peak signals and amplifying the signals that have low amplitude of OFDM signal, hence the name Clipping and Amplification method. The method is then simulated and detailed comparisons in terms of PAPR reduction with other methods are made. Comparison among different M-array modulation techniques is made to draw the conclusion for the best suited modulation technique for OFDM in terms of PAPR reduction. Finally, relations among PAPR, threshold of clipping, threshold of amplification and CCDF are established. Results show that our proposed approach gives better performance than clipping method at the expense of increased CCDF.