PAR reduction in OFDM via active constellation extension

23 January 2004

conference paper
Published by Institute of Electrical and Electronics Engineers (IEEE)

Vol. 4 (15206149) , 525
https://doi.org/10.1109/icassp.2003.1202695

Abstract

The high peak-to-average power ratio (PAR) in orthogonal frequency division multiplexing (OFDM) modulation systems can significantly limit performance. Methods exist which alter or introduce new signal constellations to combat large signal peaks. We present an improved PAR-reduction method that dynamically extends outer constellation points in active (data-carrying) channels, within margin-preserving constraints, in order to minimize the peak magnitude. This scheme simultaneously decreases the bit error rate slightly while substantially reducing the peak magnitude of an OFDM transmit block and requiring no side information. PAR reduction for an approximated analog signal is considered, and a 4.5 dB reduction is obtained for 256-channel QPSK OFDM. The results show great promise for use in commercial systems.

Keywords

This publication has 2 references indexed in Scilit:

Peak power reduction in OFDM and DMT via active channel modification
Published by Institute of Electrical and Electronics Engineers (IEEE) ,2003
Controlling clipping probability in DMT transmission
Published by Institute of Electrical and Electronics Engineers (IEEE) ,2002