PAPR Reduction Using Hybrid Technique for Optical OFDM System

Abstract

At present time Visible Light Communications (VLC) system has done on orthogonal frequency division multiplexing (OFDM) method and gained big attention in modern communications. The reason for that is the urgent requirement for massive data rate and robust communication in emerging new digital technologies. The big problem for this technique is the more peak-to-average-power-ratio (PAPR) effect. as a natural effect for implementing the OFDM method.

The PAPR effect as a consequence of this technique has been leading to the non-linear clipping distortion at light emitting-diode (LED), which was the main problem in OFDM VLC systems

In this paper, a hybrid technique was proposed to reduce the PAPR using combined companding clipping technique.

The proposed technique was evaluated using different QAM modulation orders with different IFFT size. The simulation showed that the proposed model for this technique provides a PAPR reduction gains in the range of 2.2 dB, this was compared to the original VLC-OFDM signal.

The simplicity of this work will lead us to implement this technique practically with the   existed ICs in the markets.

Keywords: OFDM, VLC, PAPR, Companding, Clipping.