Implement PAPR Reduction in OFDM System UsingReduced Complexity PTS with Companding

Abstract

A non-constant envelope with high peaks is a main disadvantage of Orthogonal Frequency Division Multiplexing(OFDM). These high peaks produce signal excursions into non-linear region of operation of the Power Amplifier (PA) atthe transmitter, thereby leading to non-linear distortions and spectral spreading. The probabilistic methodsscramble the signal by computing with phase factors.Partial transmit Sequence (PTS) is one of the techniqueswhich reduces PAPR. The computational complexity ofPTS can be reduced by using cost function Qs for eachOFDM symbol. The symbols with Qn ≥ threshold areconsidered as the signal with lowest PAPR. To promote thelowest PAPR a μ- law and A- law companding is usedwithout amplifying the complexity.