Author : Darshankumar C. Dalwadi and Himanshu B. Soni

Orthogonal Frequency Division Multiplexing (OFDM) is basically a frequency division multiplexing technique which uses a multicarrier scheme. Due to the efficient behavior in multipath fading environment OFDM used in many physical wireless systems. OFDM suffers from high Peak to Average Power Ratio (PAPR) compared to the single carrier systems. In this paper we have presented a PAPR reduction technique for Coded OFDM (COFDM) systems with scrambling approach. We have evaluated channel effect with respect to the Binary Phase Shift Keying(BPSK), Quadrature Phase Shift Keying(QPSK) and M-ary Quadrature Amplitude Modulation(M-QAM) technique. We have derived the new analytical expression for PAPR reduction technique using Proposed method for BPSK, QPSK and M-ary QAM modulation. In this paper we have present the noble PAPR reduction technique that is based on the combination of probabilistic approach and coded approach. The proposed scrambling approach is used to scramble an input data block of the Coded OFDM symbols and transmit any one of the data block with the lower PAPR so that the occurance of the probability of high PAPR can be reduced. In the proposed algorithm the out-of-band radiation is reduced as well as complexity of physical system is low.

Keywords: Peak to Average Power Ratio (PAPR), Coded Orthogonal Frequency Division Multiplexing (COFDM), Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK), Quadrature amplitude modulation (QAM).

Article published in International Journal of Current Engineering and Technology, Vol.4, No.5 (Oct-2014)