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Bandwidth efficient concatenated coding schemes

IET COMMUNICATIONS 2010年第1期4卷 26-31页

作者： Ma, S. -C. Natl Taipei Univ Technol Dept Elect Engn Taipei 106 Taiwan

Concatenated coded modulation is a powerful method for constructing coding schemes with large coding gain and low decoding complexity. For the concatenated scheme, the outer code has redundancy and the overall transmission rate is reduced. The problem of bandwidth expansion can be overcome by two procedures. First, the code rate of inner codes is increased with a special coding design. Second, a two-level concatenated scheme is constructed to compensate the rate loss. This way, the low-complexity concatenated coded modulation schemes can be designed without bandwidth expansion as compared with the uncoded scheme.

关键词： low-complexity concatenated coded modulation scheme concatenated codes modulation coding computational complexity decoding complexity two-level concatenated scheme bandwidth efficient concatenated coding schemes decoding Codes

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Improving the Performance of Chaos-Based modulations Via Serial Concatenation

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS 2010年第2期57卷 448-459页

作者： Escribano, Francisco J. Lopez, Luis Sanjuan, Miguel A. F. Univ Alcala de Henares Escuela Politecn Super Dept Teoria Senal & Comunicac Alcala De Henares 28805 Spain Univ Rey Juan Carlos Dept Sistemas Telemat & Computac Mostoles 28933 Spain Univ Rey Juan Carlos Dept Fis Mostoles 28933 Spain

This paper proposes a serially concatenated system with an outer convolutional channel encoder and an inner chaos-based coded modulator. With the help of the principles of symbolic dynamics, the chaotic modulation can be described in terms of a trellis. Owing to this, we show that the resulting system can be designed and analyzed following developments made for serially concatenated channel codes (SCCCs) or bit-interleaved coded-modulation systems. We show how the iterative decoding algorithm used in this concatenated framework can be analyzed through the well-known extrinsic information transfer chart device and how the bit error rate can be bounded using the transfer function of the convolutional channel encoder. Comparison with a related SCCC system in both additive white Gaussian noise and frequency-nonselective fading channels shows that this kind of chaos-based systems keeps the potential advantages of coded-modulation-based systems. We are thus confident that the principles shown here can lead to the design of competitive chaotic discrete communication systems.

关键词： Channel coding chaos concatenated coding fading channels modulation coding

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Construction of Maximum Run-Length Limited Codes Using Sequence Replacement Techniques

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IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2010年第2期28卷 200-207页

作者： van Wijngaarden, Adriaan J. Immink, Kees A. Schouhamer Alcatel Lucent Bell Labs Math Networks & Commun Dept Murray Hill NJ USA Turing Machines Inc Rotterdam Netherlands Essen Univ Inst Expt Math Essen Germany Data Storage Inst Singapore Singapore

The sequence replacement technique converts an input sequence into a constrained sequence in which a prescribed subsequence is forbidden to occur. Several coding algorithms are presented that use this technique for the construction of maximum run-length limited sequences. The proposed algorithms show how all forbidden subsequences can be successively or iteratively removed to obtain a constrained sequence and how special subsequences can be inserted at predefined positions in the constrained sequence to represent the indices of the positions where the forbidden subsequences were removed. Several modifications are presented to reduce the impact of transmission errors on the decoding operation, and schemes to provide error control are discussed as well. The proposed algorithms can be implemented efficiently, and the rates of the constructed codes are close to their theoretical maximum. As such, the proposed algorithms are of interest for storage systems and data networks.

关键词： modulation coding run length codes block codes variable length codes error analysis error control coding

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Analysis of Chaos-Based Coded modulations under Intersymbol Interference

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JOURNAL OF COMPUTERS 2010年第10期5卷 1459-1467页

作者： Escribano, Francisco J. Lopez, Luis Sanjuan, Miguel A. F. Univ Alcala Dept Teoria Senal & Comunicac Alcala De Henares 28805 Spain Univ Rey Juan Carlos Dept Sistemas Telemat & Computac Mostoles 28933 Spain Univ Rey Juan Carlos Dept Fis Mostoles 28933 Spain

Chaos-based communications systems have shown to be of potential interest in some kinds of dispersive channels. In this paper we analyze the behavior of a class of chaos-based coded modulations (CCM's) in channels with time-invariant intersymbol interference (ISI). We use the ISI distance spectrum of the CCM's to calculte bounds for the bit error rate (BER), and we provide the analytical condition a CCM has to comply to stand a limited quantity of ISI. We explain also the effect of the main modelling parameter of this class of chaos-based systems, and we show that the dynamics of the underlying chaotic map is in each case the main factor to account for the final performance. The results show that CCM systems are of potential interest in this kind of distorting environment.

关键词： Chaos Intersymbol interference modulation coding Error analysis

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Approaching the Non-Linear Shannon Limit

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2010年第4期28卷 423-433页

作者： Ellis, Andrew D. Zhao, Jian Cotter, David Univ Coll Cork Tyndall Natl Inst Cork Transmiss & Sensors Grp Cork Ireland Univ Coll Cork Dept Phys Cork Ireland Univ Coll Cork Tyndall Natl Inst Cork Photon Syst Grp Cork Ireland

We review the recent progress of information theory in optical communications, and describe the current experimental results and associated advances in various individual technologies which increase the information capacity. We confirm the widely held belief that the reported capacities are approaching the fundamental limits imposed by signal-to-noise ratio and the distributed non-linearity of conventional optical fibres, resulting in the reduction in the growth rate of communication capacity. We also discuss the techniques which are promising to increase and/or approach the information capacity limit.

关键词： Information rates modulation coding non-linear optics wavelength division multiplexing

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Envelope coding in Auditory Nerve Fibers Following Noise-Induced Hearing Loss

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JARO-JOURNAL OF THE ASSOCIATION FOR RESEARCH IN OTOLARYNGOLOGY 2010年第4期11卷 657-673页

作者： Kale, Sushrut Heinz, Michael G. Purdue Univ Weldon Sch Biomed Engn W Lafayette IN 47907 USA Purdue Univ Dept Speech Language & Hearing Sci W Lafayette IN 47907 USA

Recent perceptual studies suggest that listeners with sensorineural hearing loss (SNHL) have a reduced ability to use temporal fine-structure cues, whereas the effects of SNHL on temporal envelope cues are generally thought to be minimal. Several perceptual studies suggest that envelope coding may actually be enhanced following SNHL and that this effect may actually degrade listening in modulated maskers (e.g., competing talkers). The present study examined physiological effects of SNHL on envelope coding in auditory nerve (AN) fibers in relation to fine-structure coding. Responses were compared between anesthetized chinchillas with normal hearing and those with a mild-moderate noise-induced hearing loss. Temporal envelope coding of narrowband-modulated stimuli (sinusoidally amplitude-modulated tones and single-formant stimuli) was quantified with several neural metrics. The relative strength of envelope and fine-structure coding was compared using shuffled correlogram analyses. On average, the strength of envelope coding was enhanced in noise-exposed AN fibers. A high degree of enhanced envelope coding was observed in AN fibers with high thresholds and very steep rate-level functions, which were likely associated with severe outer and inner hair cell damage. Degradation in fine-structure coding was observed in that the transition between AN fibers coding primarily fine structure or envelope occurred at lower characteristic frequencies following SNHL. This relative fine-structure degradation occurred despite no degradation in the fundamental ability of AN fibers to encode fine structure and did not depend on reduced frequency selectivity. Overall, these data suggest the need to consider the relative effects of SNHL on envelope and fine-structure coding in evaluating perceptual deficits in temporal processing of complex stimuli.

关键词： temporal coding sensorineural hearing loss phase locking modulation coding

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Guest editorial data communication techniques for storage channels and networks

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IEEE Journal on Selected Areas in Communications 2010年第2期28卷 129-134页

作者： Ölçer, Sedat Kavcic, Aleksandar Vasic, Bane Wilson, Bruce Xu, Lihao Lea, Chin-Tau IBM Research - Zurich 8803 Rueschlikon Switzerland University of Hawaii Honolulu HI 96822 United States University of Arizona Tucson AZ 85721 United States Hitachi Global Storage Technologies San Jose CA 95193 United States Wayne State University Detroit MI 48202 United States

Since the inception of direct access magnetic storage about 55 years ago, data storage has both benefited from and given rise to extraordinary progress in many technological areas, including materials science, tribology, servo control and actuation, and signal processing and coding. The number of data bits that can be stored in a unit area - the areal recording density - has increased by eight orders of magnitude for harddisk magnetic storage, with compound annual growth rates at times exceeding 100%. Moreover, the cost of this form of storage has dropped by about seven orders of magnitude. For this reason, data storage has been one of the main enablers of the information technology revolution. According to a recent estimation by the technology analysis firm IDC, the amount of data created worldwide has now started to exceed the capacity of storage that is physically available. This so-called digital universe is forecasted to grow explosively and reach more than 10 21 bytes (1 ZB) in 2011.

关键词： Data communication Probes Signal processing Magnetic recording Magnetic noise Noise shaping Equalizers Perpendicular magnetic recording Performance analysis modulation coding

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Discrete Time Faster-than-Nyquist Signalling

Discrete Time Faster-than-Nyquist Signalling

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IEEE Global Telecommunications Conference (GLOBECOM 2010)

作者： McGuire, Michael Sima, Mihai Univ Victoria Dept Elect & Comp Engn Victoria BC V8W 3P6 Canada

ISBN: (纸本)9781424456383

Increasing the symbol rate up to 25% faster than the Nyquist criteria for a digital communications system with QPSK modulation with AWGN channel does not significantly increase the bit error rate or required transmission bandwidth. This so-called Faster-than-Nyquist (FTN) signalling has not been used in commercially deployed communications systems since the previously proposed implementation schemes required large receiver complexity. This paper introduces a reformulation of FTN signalling in terms of a non-square matrix multiplied by a sample vector of modulated QPSK symbols. It is shown that with this formulation the receiver complexity to detect the transmitted data for an AWGN channel is well within the complexity bounds for standard digital communication systems. This formulation enables an analysis of FTN signalling directly comparing it to standard higher order modulation and data coding techniques.

关键词： modulation coding Faster than Nyquist signalling

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modulation Code and Signal Characteristics for Signal Waveform modulation Optical Disc

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JAPANESE JOURNAL OF APPLIED PHYSICS 2010年第8期49卷 08KB01-08KB01页

作者： Liu, Hailong Pei, Jing Pan, Longfa Ni, Yi Tsinghua Univ Opt Memory Natl Engn Res Ctr Dept Precis Instrument & Mech Beijing 100084 Peoples R China Yanshan Univ Measurement Technol & Instrumentat Key Lab Hebei Qinhuangdao 066004 Hebei Peoples R China

A high-efficient and novel varying-level multilevel run-length-limited modulation code is proposed for signal waveform modulation (SWM) optical discs. The proposed code is composed of a maximum transition run (MTR) code and a level modulation process. The MTR code is employed to realize high code rate and satisfy the requirements of channels. Level modulation is used to eliminate inappropriate codewords for SWM channels and determine the level numbers for different runs. The rate of the presented code is 7/8 bits/symbols, and the recording density parameter RBPF (recording bits per 400 nm) is 2.26, which is 50.7% more than that of a digital versatile disc (DVD). The realization of the proposed code in SWM discs and the corresponding signal characteristics are also shown. With the run-length detection and level detection solution, the bit error rate (BER) is less than 2 x 10(-4), which is feasible for SWM multilevel optical discs. (C) 2010 The Japan Society of Applied Physics

关键词： RECORDING CHANNELS MULTILEVEL shunt wound motors signal waveform code rate Codes modulation coding

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A Novel Self Organizing Framework for Adaptive Frequency Reuse and Deployment in Future Cellular Networks

A Novel Self Organizing Framework for Adaptive Frequency Reu...

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21st Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)

作者： Imran, A. Imran, M. A. Tafazolli, R. Univ Surrey Ctr Commun Syst Res Guildford GU2 5XH Surrey England

ISBN: (纸本)9781424480166

Recent research on Frequency Reuse (FR) schemes for OFDM/OFDMA based cellular networks (OCN) suggest that a single fixed FR cannot be optimal to cope with spatiotemporal dynamics of traffic and cellular environments in a spectral and energy efficient way. To address this issue this paper introduces a novel Self Organizing framework for adaptive Frequency Reuse and Deployment (SO-FRD) for future OCN including both cellular (e. g. LTE) and relay enhanced cellular networks (e. g. LTE Advance). In this paper, an optimization problem is first formulated to find optimal frequency reuse factor, number of sectors per site and number of relays per site. The goal is designed as an adaptive utility function which incorporates three major system objectives;1) spectral efficiency 2) fairness, and 3) energy efficiency. An appropriate metric for each of the three constituent objectives of utility function is then derived. Solution is provided by evaluating these metrics through a combination of analysis and extensive system level simulations for all feasible FRD's. Proposed SO-FRD framework uses this flexible utility function to switch to particular FRD strategy, which is suitable for system's current state according to predefined or self learned performance criterion. The proposed metrics capture the effect of all major optimization parameters like frequency reuse factor, number of sectors and relay per site, and adaptive coding and modulation. Based on the results obtained, interesting insights into the tradeoff among these factors is also provided.

关键词： OFDM based cellular network OFDM modulation OFDMA based cellular network adaptive codes adaptive coding adaptive frequency deployment adaptive frequency reuse adaptive modulation adaptive utility function cellular environment cellular radio energy efficiency objective fairness objective flexible utility function frequency allocation frequency division multiple access future cellular network modulation coding optimal frequency reuse factor optimization problem relay enhanced cellular network self organizing framework spatiotemporal dynamics spectral efficiency objective telecommunication traffic traffic

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