Improved Companding Technique with Different Modulation Schemes for Better Papr in of DM Systems

Authors

  • A. Hema Malini
  • M. Selvi

Abstract

Orthogonal Frequency Division Multiplexing (OFDM) is a digital multicarrier modulation using many closely spaced subcarriers. The problem in transmitted signal of OFDM scheme is high Peak-to-Average-Power Ratio (PAPR) andit leads the transmitter’s high power amplifier into its non-linear region which cause high power consumption and degradation of BER performance. Among various techniques companding scheme appears attractive for its simplicity and effectiveness. The reduction in input sequence auto-correlation is done by Discrete Cosine Transform(DCT)prior to IFFT operation for PAPR reduction. In this paper, a combination of DCT and Improved two ? law companding with an offset, is proposed to achieve better PAPR reduction and efficient bandwidth utilization for lower and higher orders in PSK and QAM modulation. The main idea is to show the performance of ITM with DCT on the OFDM signal with reduced PAPR using simulation.

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Published

2020-01-19

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Section

Articles