Reduction PAPR of OFDM Signals by Combining Grouped DCT Precoding with PTS

Zhongpeng Wang,Shoufa Chen

doi:10.4236/jsip.2014.54016

Abstract

The high peak-to-average power ratio (PAPR) is one of the serious problems in the application of OFDM technology. In this paper, an improved partial transmit sequence (PTS) scheme based on combining the grouped discrete cosine transform (DCT) with PTS technique is proposed. In the proposed scheme, the adjacent partitioned data are firstly transformed by a DCT into new modified data. After that the proposed scheme utilizes the conventional PTS technique to further reduce the PAPR of the OFDM signal. The performance of the PAPR is evaluated using a computer simulation. The simulation results indicate that the proposed scheme may improve the PAPR performance compared with the conventional PTS scheme, the grouped DCT scheme, and original OFDM respectively.

Highlights

Orthogonal frequency division multiplexing (OFDM) has been recently seen rising popularity in wireless applications
We present a grouped discrete cosine transform (DCT) precoding based Partial Transmit Sequence (PTS) technique for peak-to-average power ratio (PAPR) reduction in OFDM systems
The complement cumulative distribution function (CCDF) of the PAPR of OFDM signals is used to evaluate the performance of proposed scheme in comparison with other conventional reduction PAPR methods

Summary

Introduction

Orthogonal frequency division multiplexing (OFDM) has been recently seen rising popularity in wireless applications. Many techniques have been proposed to reduce the PAPR of OFDM signals. (2014) Reduction PAPR of OFDM Signals by Combining Grouped DCT Precoding with PTS. These schemes can mainly be categorized into signal scrambling techniques, such as PTS, and signal distortion techniques such as clipping Among those PAPR reduction methods, the simplest scheme is to use the clipping process. In order to improve the PAPR performance of OFDM signal many schemes based on combing PTS or SLM and precoding have been proposed. In literatures [9], the grouped DCT precoding technique is proposed to reduce the PAPR of optical OFDM signal. We present a grouped DCT precoding based PTS technique for PAPR reduction in OFDM systems. In the proposed system we applied DCT based precoder after the data partition and before the IFFT in the PTS based on OFDM (PTS-OFDM) system

OFDM Signal Model and PAPR Problem

Grouped DCT Precoding

Proposed Scheme

Simulation Results

Conclusion