Reducing Peak-to-Average Power Ratio of a Turbo Coded OFDM

Spyridon K. Chronopoulos, Vasilis Christofilakis, Giorgos Tatsis, Panos Kostarakis

Physics Department, University of Ioannina, Ioannina, Greece.

DOI: 10.4236/wet.2012.34028                

Abstract

Peak to Average Power Ratio (PAPR) is defined as the instantaneous power (maximum value) to the average power ratio. PAPR is considered to be a major problem in OFDM systems. This problem can cause radical unexpected behavior of the signal fluctuation. This fluctuation is constituted by a large number of power states. The enormous number of these states leads to an additional complexity of ADCs and DACs. This research addresses the previous problem in OFDM systems utilizing Turbo Codes. μLaCP technique is employed for the purpose of decreasing PAPR. Moreover, our OFDM system was simulated in the presence of an AWGN channel with four types of codes (without the presence of ADCs and DACs). These were constituted of PCCC (typical and new), SCCC, and Convolutional Codes. Our Turbo Coded OFDM exhibited unchanged BER performance before and after the use of μLaCP technique. This was accomplished by modifying our previous PAPR reduction technique without sacrificing greatly its attributes.

Keywords

Orthogonal Frequency Division Multiplexing; Peak to Average Power Ratio; μ-Law; μLaCP; μLaIF; Parallel Concatenated Convolutional Codes; A Posteriori Probability; Cyclic Prefix; Zero Padding; Peak Ratio; Bit Error Rate

Conflicts of Interest

The authors declare no conflicts of interest.

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