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Generalized ReedMuller Codes and Power Control in OFDM Modulation
 IEEE Trans. Inform. Theory
, 2000
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A Comparison Of Peak Power Reduction Schemes For OFDM
 in Proc IEEE GlobeCom
, 1997
"... Two powerful and distortionless peak power reduction schemes for Orthogonal Frequency Division Multiplexing (OFDM) are compared. One investigated technique is selected mapping (SLM) where the actual transmit signal is selected from a set of signals and the second scheme utilizes phase rotated partia ..."
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Cited by 44 (1 self)
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Two powerful and distortionless peak power reduction schemes for Orthogonal Frequency Division Multiplexing (OFDM) are compared. One investigated technique is selected mapping (SLM) where the actual transmit signal is selected from a set of signals and the second scheme utilizes phase rotated partial transmit sequences (PTS) to construct the transmit signal. Both approaches are very flexible as they do not impose any restriction on the modulation applied in the subcarriers or on their number. They both introduce some additional system complexity but nearly vanishing redundancy to achieve markedly improved statistics of the multicarrier transmit signal. The schemes are compared by simulation results with respect to the required system complexity and transmit signal redundancy. 1. INTRODUCTION Besides a lot of advantages, some drawbacks become apparent, when using OFDM in transmission systems. A major obstacle is that the multiplex signal exhibits a very high peaktoaverage power ra...
A Novel Peak Power Reduction Scheme For OFDM
 in Proc PIMRC, (XXX
, 1997
"... An efficient and distortionless scheme for peak power reduction in Orthogonal Frequency Division Multiplexing (OFDM) is proposed, which introduces some additional complexity but nearly vanishing redundancy. The approach is very flexible and works with arbitrary numbers of subcarriers and without res ..."
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Cited by 44 (1 self)
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An efficient and distortionless scheme for peak power reduction in Orthogonal Frequency Division Multiplexing (OFDM) is proposed, which introduces some additional complexity but nearly vanishing redundancy. The approach is very flexible and works with arbitrary numbers of subcarriers and without restriction on the type of modulation applied in them. The core of the approach is the coordination of appropriately phase rotated signal parts to minimize the peak power of the multiplex signal. The improved statistics of peak power in the optimized transmit signal are demonstrated by simulation results. Finally, it is shown that this scheme is close to the theoretical limit curve of redundancy versus minimum peak toaverage power ratio (PAR). 1. INTRODUCTION When using OFDM in transmission systems, the transmit signal will occasionally exhibit very high peaks. Nonlinearities may become overloaded, causing intermodulation among the subcarriers and  more critical  undesired outof...
A new approach for evaluating clipping distortion in Multicarrier systems
 in IEEE Journal on Selected Areas in Communications
, 2002
"... Abstract — Multicarrier signals are known to suffer from a high peaktoaverage power ratio (PAPR), caused by the addition of a large number of independently modulated subcarriers in parallel at the transmitter. When subjected to a peaklimiting channel, such as a nonlinear power amplifier, these s ..."
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Cited by 34 (0 self)
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Abstract — Multicarrier signals are known to suffer from a high peaktoaverage power ratio (PAPR), caused by the addition of a large number of independently modulated subcarriers in parallel at the transmitter. When subjected to a peaklimiting channel, such as a nonlinear power amplifier, these signals may undergo significant spectral distortion, leading to both inband and outofband interference, and an associated degradation in system performance. This paper characterizes the distortion caused by the clipping of multicarrier signals in a peaklimiting (nonlinear) channel. Rather than modeling the effects of distortion as additive noise, as is widespread in the literature, we identify clipping as a rare event and focus on evaluating system performance based on the conditional probability of bit error given the occurrence of such an event. Our analysis is based on the asymptotic properties of the large excursions of a stationary Gaussian process, and offers important insights into both the true nature of clipping distortion, as well as the consequent design of schemes to alleviate this problem. Keywords — PeaktoAverage Ratio, OFDM, Clipping. I.
The Colonial Construction of “Communalism
 British Writings on Banaras in the Nineteenth Century’, in Veena Das (ed.), Mirors of Violence: Communities, Riots and Survivors in South Asia
, 1990
"... Partial Transmit Sequence (PTS) is a promising technique to reduce Peaktoaverage power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals. However optimum PTS (OPTS) needs exhaustive search over all combinations of allowed phase weighting factors. It results in high computat ..."
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Cited by 25 (0 self)
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Partial Transmit Sequence (PTS) is a promising technique to reduce Peaktoaverage power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals. However optimum PTS (OPTS) needs exhaustive search over all combinations of allowed phase weighting factors. It results in high computational complexity. Grouping Phase Weighting (GPW) technique is a method which has reduced computational complexity while same PAPR reduction capability as compared to OPTS. In this paper we propose a novel technique known as Suboptimum Grouping Phase Weighting (SGPW) Method which not only reduces the computational complexity but also have an advantage of increment in PAPR reduction performance as compared to Grouping Phase Weighting (GPW) method.
PAR Reduction in Multicarrier Transmission Systems
 ANSI Document, T1E1.4 Technical Subcommittee
, 1998
"... This contribution, which is based on [1], 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 perfo ..."
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Cited by 19 (5 self)
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This contribution, which is based on [1], 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 peaktoaverage 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, ...
Dispersion of Gaussian channels
 IEEE Int. Symp. Inform. Theory
, 2009
"... Abstract—The minimum blocklength required to achieve a given rate and error probability can be easily and tightly approximated from two key channel parameters: the capacity and the channel dispersion. The channel dispersion gauges the variability of the channel relative to a deterministic bit pipe w ..."
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Cited by 17 (3 self)
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Abstract—The minimum blocklength required to achieve a given rate and error probability can be easily and tightly approximated from two key channel parameters: the capacity and the channel dispersion. The channel dispersion gauges the variability of the channel relative to a deterministic bit pipe with the same capacity. This paper finds the dispersion of the additive white Gaussian noise (AWGN) channel, the parallel AWGN channel, and the Gaussian channel with nonwhite noise and intersymbol interference. I.
Two Constructions of 16QAM Golay Complementary Sequences
 IEEE Trans. Inform. Theory
"... We present twocL8Lx4kx[8[g of 16QAM Golayc omplementary sequenc4k The size of the set ofc onstrucxI sequenc is (14+ 12m)(m!/2)4 m+1 . Of these, when employed in an OFDM system, (m!/2)4 m+1sequenc4 have PMEPR (peak to mean envelope power ratio) bounded above by 3.6, three subsets of size (4+4m)( ..."
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Cited by 16 (0 self)
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We present twocL8Lx4kx[8[g of 16QAM Golayc omplementary sequenc4k The size of the set ofc onstrucxI sequenc is (14+ 12m)(m!/2)4 m+1 . Of these, when employed in an OFDM system, (m!/2)4 m+1sequenc4 have PMEPR (peak to mean envelope power ratio) bounded above by 3.6, three subsets of size (4+4m)(m!/2)4 m+1 c4 tainsequencfi having PMEPRs less than of 2.8, 2.0, and 1.2 respec40 ely, and a subset of size (m!/2)4 m+1 c4 tains sequenc4 that have PMEPR upperbounded by 0.4. 1 Introducti6 In an excIx4k paper [2], Golayc0xfi04k0L thec40NNIg4k0L ofc4Ifi]]x4 tary binary Golay sequencxg Thesesequenc[ have found numerousapplicg8fi]4 in various fields ofscx[x] and engineering. An important applic4k00 of Golay c0[8]I4k tary sequenc4 is to orthogonalfrequenc division multiplexing (OFDM). This is ac0I unic0L4k tec hnique with a long historywhic h is rapidly emerging as atec hnology ofc hoic in wireless applic4k8L[fi International standards suc h as IEEE 802.11 are employing OFDM for wireless LANapplic4k8][x For wireless applic4k8][x an OFDMbased systemc an be ofpartic4k8 interest becLgI it provides a greater immunity to impulse noise and fast fades and eliminates the need for equalizers, while e#ce4 t hardware implementationsci be realized using FFTtec hniques. One of the major issues in deploying OFDM is the high peak to mean enevelope power ratio (PMEPR) ofunc ded OFDM signals. To prevent spec080 growth of the OFDM signal in the form of intermodulation amongst subc arriers and outofband radiation, the transmit amplifier must be operated in its linear region. Amplifiers with large linear range are expensive and thisc anincNNgI the ce4 of the implementation of OFDM. Moreover, If the peak transmit power is limited, either 1 by regulatory or applic4k]I c onstraints, then a h...
Another Application for Trellis Shaping: PAR Reduction for DMT (OFDM)
, 2000
"... A bound for the possible reduction of the peaktoaverage ratio (PAR) dependent on the rate as well as possible practical procedures are presented. The idea of trellis shaping, originally used to minimize average transmit power in singlecarrier systems, is applied to the problem of PAR reduction in ..."
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Cited by 16 (1 self)
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A bound for the possible reduction of the peaktoaverage ratio (PAR) dependent on the rate as well as possible practical procedures are presented. The idea of trellis shaping, originally used to minimize average transmit power in singlecarrier systems, is applied to the problem of PAR reduction in multicarrier transmission. Its impact, as a function of code rate, as well as design practicability is considered using metrics in both time and frequency domain.
Multicarrier pap reduction method using suboptimal PTS with threshold
 IIEEE Transaction on Broadcasting
"... Abstract—This paper presents an orthogonal frequency division multiplexing (OFDM) system, which through the use of suboptimal PTS combined with a preset threshold, achieves low computational complexity to find optimum weighting factors. A specific bit in weighting factor that leads to a smaller pe ..."
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Cited by 13 (0 self)
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Abstract—This paper presents an orthogonal frequency division multiplexing (OFDM) system, which through the use of suboptimal PTS combined with a preset threshold, achieves low computational complexity to find optimum weighting factors. A specific bit in weighting factor that leads to a smaller peaktoaverage power ratio ( ) is identified from the suboptimum method. And a specific threshold, which found from the OFDM frame probability, is also applied to reduce computational complexity. The performance of the proposed method was slightly degraded compared to that of optimum method, PTS. However, the complexity of the proposed method was remarkably lower than that of optimum method. Index Terms—OFDM system, peaktoaverage power ratio, PTS. I.