An improved peak-to-average-power ratio reduction algorithm for multicarrier communications.
ABSTRACT An improved peak-to-average-power ratio reduction algorithm for discrete multitone systems is deduced by simultaneous optimization of the quadrature-amplitude-modulation constellation and the unused discrete multitone subsymbols. The proposed method is also applicable to multicarrier systems where all subchannels are active. Our simulations demonstrate that considerable performance improvement can be achieved over several existing methods at the cost of increased computational complexity.
Conference Paper: Peak power reduction in OFDM and DMT via active channel modification[Show abstract] [Hide abstract]
ABSTRACT: Orthogonal frequency division multiplexing (OFDM) and discrete multitone (DMT) modulation offer many advantages for digital data transmission and have been adopted for several important standards. Their primary drawback is a high peak-to-average power ratio (PAR). Methods which introduce compensation signals in unused channels, first developed by Gatherer and Polley (see Proceedings of the 31st Asilomar Conference on Signals, Systems, and Computers, p.578-84, 1997), are among the more promising methods for reducing the PAR. However these methods apply only to systems with unused channels or require the sacrifice of data rate for PAR reduction. We present a new method for PAR reduction using active (data-carrying) channels which dynamically moves outer constellation points, within margin-preserving constraints, to minimize the peak magnitude. This scheme simultaneously decreases the bit error rate slightly while substantially reducing the peak magnitude; simulations show peak reductions of slightly more than 6 dB.Signals, Systems, and Computers, 1999. Conference Record of the Thirty-Third Asilomar Conference on; 02/1999
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ABSTRACT: The general technique of parallel transmission on many carriers, called multicarrier modulation (MCM), is explained. The performance that can be achieved on an undistorted channel and algorithms for achieving that performance are discussed. Ways of dealing with channel impairments and of improving the performance through coding are described, and implementation methods are considered. Duplex operation of MCM and the possible use of this on the general switched telephone network are examined.< >IEEE Communications Magazine 06/1990; · 4.46 Impact Factor
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ABSTRACT: This contribution, which is based on , proposes a new family of methods to reduce Peak to Average power Ratio (PAR) in Discrete MultiTone (DMT) and Orthogonal Frequency Division Multiplexing (OFDM) systems. This new family of algorithms can be applied with different levels of complexity and performance depending on our application constraints. Using the low complexity algorithms in our family, we can achieve 3dB of PAR reduction with 2N multiply /adds per DMT symbol and a data rate loss of less than :2%, or achieve 4dB of PAR reduction with 6N multiply/adds per symbol and a data rate loss of less than 1%. At higher complexity, 6 Gamma 10dB of PAR reduction can be achieved for NlogN complexity per symbol. Tellado, J. and Cioffi, J.M.--PAR Reduction: 2 1 Introduction The high peak-to-average ratio of 15 dB in the Issue 1 and Issue 2 T1.413 ADSL standard DMT transmission technology has led to significant contributions on a variety of creative methods to reduce PAR [2, 3, 4, 5, 6, ...10/1998;