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Information Theory, IEEE Transactions on

Issue 5 • Date May 2009

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Displaying Results 1 - 25 of 40
  • Table of contents

    Publication Year: 2009 , Page(s): C1 - C4
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    Freely Available from IEEE
  • IEEE Transactions on Information Theory publication information

    Publication Year: 2009 , Page(s): C2
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  • The Universal LZ77 Compression Algorithm Is Essentially Optimal for Individual Finite-Length N -Blocks

    Publication Year: 2009 , Page(s): 1941 - 1944
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (105 KB) |  | HTML iconHTML  

    Consider the case where consecutive blocks of N letters of a semi-infinite individual sequence X over a finite alphabet are being compressed into binary sequences by some one-to-one mapping. No a priori information about X is available at the encoder, which must therefore adopt a universal data-compression algorithm. It is known that there exist a number of asymptotically optimal universal data co... View full abstract»

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  • Joint Universal Lossy Coding and Identification of Stationary Mixing Sources With General Alphabets

    Publication Year: 2009 , Page(s): 1945 - 1960
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (397 KB) |  | HTML iconHTML  

    In this paper, we consider the problem of joint universal variable-rate lossy coding and identification for parametric classes of stationary beta -mixing sources with general (Polish) alphabets. Compression performance is measured in terms of Lagrangians, while identification performance is measured by the variational distance between the true source and the estimated source. Provided that ... View full abstract»

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  • Nonlinear Sparse-Graph Codes for Lossy Compression

    Publication Year: 2009 , Page(s): 1961 - 1975
    Cited by:  Papers (21)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (814 KB) |  | HTML iconHTML  

    We propose a scheme for lossy compression of discrete memoryless sources: The compressor is the decoder of a nonlinear channel code, constructed from a sparse graph. We prove asymptotic optimality of the scheme for any separable (letter-by-letter) bounded distortion criterion. We also present a suboptimal compression algorithm, which exhibits near-optimal performance for moderate block lengths. View full abstract»

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  • Finding All Small Error-Prone Substructures in LDPC Codes

    Publication Year: 2009 , Page(s): 1976 - 1999
    Cited by:  Papers (25)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (1530 KB) |  | HTML iconHTML  

    It is proven in this work that it is NP-complete to exhaustively enumerate small error-prone substructures in arbitrary, finite-length low-density parity-check (LDPC) codes. Two error-prone patterns of interest include stopping sets for binary erasure channels (BECs) and trapping sets for general memoryless symmetric channels. Despite the provable hardness of the problem, this work provides an exh... View full abstract»

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  • Simple Classes of Constrained Systems With Unconstrained Positions That Outperform the Maxentropic Bound

    Publication Year: 2009 , Page(s): 2000 - 2003
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (248 KB) |  | HTML iconHTML  

    The Wijngaarden-Immink (WI) scheme is a combined modulation/ECC coding scheme, where arbitrary user data are translated into a constrained sequence in which predefined positions are reserved for error-correcting codes (ECC) parity. Besides offering the benefit of combined modulation/ECC coding, the WI scheme has two extra benefits. They are (a) error propagation is limited to the constrained symbo... View full abstract»

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  • High-Rate, Single-Symbol ML Decodable Precoded DSTBCs for Cooperative Networks

    Publication Year: 2009 , Page(s): 2004 - 2015
    Cited by:  Papers (15)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (294 KB) |  | HTML iconHTML  

    Distributed orthogonal space-time block codes (DOSTBCs) achieving full-diversity order and single-symbol maximum-likelihood (ML) decodability have been introduced recently by Yi and Kim for cooperative networks, and an upper bound on the maximal rate of such codes along with code constructions has been presented. In this paper, a new class of single-symbol ML decodable precoded distributed space-t... View full abstract»

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  • Reversible Low-Density Parity-Check Codes

    Publication Year: 2009 , Page(s): 2016 - 2036
    Cited by:  Papers (2)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (3801 KB) |  | HTML iconHTML  

    Low-density parity-check (LDPC) codes may be decoded using a circuit implementation of the sum-product algorithm which maps the factor graph of the code. By reusing the decoder for encoding, both tasks can be performed using the same circuit, thus reducing area and verification requirements. Motivated by this, iterative encoding techniques based upon the graphical representation of the code are pr... View full abstract»

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  • The Capacity of Finite Abelian Group Codes Over Symmetric Memoryless Channels

    Publication Year: 2009 , Page(s): 2037 - 2054
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (440 KB) |  | HTML iconHTML  

    The capacity of finite Abelian group codes over symmetric memoryless channels is determined. For certain important examples, such as m -PSK constellations over additive white Gaussian noise (AWGN) channels, with m a prime power, it is shown that this capacity coincides with the Shannon capacity; i.e., there is no loss in capacity using group codes. (This had previously been known for binary-linear... View full abstract»

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  • Error-Correction Capability of Column-Weight-Three LDPC Codes

    Publication Year: 2009 , Page(s): 2055 - 2061
    Cited by:  Papers (16)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (163 KB) |  | HTML iconHTML  

    In this paper, the error-correction capability of column-weight-three low-density parity-check (LDPC) codes when decoded using the Gallager A algorithm is investigated. It is proved that a necessary condition for a code to correct all error patterns with up to k ges 5 errors is to avoid cycles of length up to 2k in its Tanner graph. As a consequence of this result, it is shown that given any alpha... View full abstract»

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  • Optimal Puncturing Ratios and Energy Allocation for Multiple Parallel Concatenated Codes

    Publication Year: 2009 , Page(s): 2062 - 2077
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (725 KB) |  | HTML iconHTML  

    We propose a systematic design framework for optimal, low-complexity punctured multiple parallel concatenated codes (MPCCs), based on minimizing the convergence threshold using extrinsic information transfer (EXIT) charts. As the convergence threshold is related to the area between the two EXIT curves, the corresponding optimization problem is equivalent to a curve-fitting problem. The EXIT curves... View full abstract»

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  • On the Existence of Perfect Space–Time Codes

    Publication Year: 2009 , Page(s): 2078 - 2082
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (123 KB) |  | HTML iconHTML  

    Perfect space-time codes are codes for the coherent multiple-input multiple-output (MIMO) channel. They have been called so since they satisfy a large number of design criteria that makes their performances outmatch many other codes. In this correspondence, we discuss the existence of such codes (or more precisely, the existence of perfect codes with optimal signal complexity). View full abstract»

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  • A Formulation of the Channel Capacity of Multiple-Access Channel

    Publication Year: 2009 , Page(s): 2083 - 2096
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (338 KB) |  | HTML iconHTML  

    The necessary and sufficient condition of the channel capacity is rigorously formulated for the N -user discrete memoryless multiple-access channel (MAC). The essence is to invoke an elementary MAC where sizes of input alphabets are not greater than the size of output alphabet. The main objective is to demonstrate that the channel capacity of an MAC is achieved by an elementary MAC included in the... View full abstract»

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  • Capacity/Storage Tradeoff in High-Dimensional Identification Systems

    Publication Year: 2009 , Page(s): 2097 - 2106
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (257 KB) |  | HTML iconHTML  

    The asymptotic tradeoff between the number of distinguishable objects and the necessary storage space (or equivalently, the search complexity) in an identification system is investigated. In the discussed scenario, high-dimensional (and noisy) feature vectors extracted from objects are first compressed and then enrolled in the database. When the user submits a random query object, the extracted no... View full abstract»

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  • Characterization of Ergodic Hidden Markov Sources

    Publication Year: 2009 , Page(s): 2107 - 2118
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (258 KB) |  | HTML iconHTML  

    An algebraic criterion for the ergodicity of discrete random sources is presented. For finite-dimensional sources, which contain hidden Markov sources as a subclass, the criterion can be effectively computed. This result is obtained on the background of a novel, elementary theory of discrete random sources, which is based on linear spaces spanned by word functions, and linear operators on these sp... View full abstract»

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  • On Analytic Properties of Entropy Rate

    Publication Year: 2009 , Page(s): 2119 - 2127
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (211 KB) |  | HTML iconHTML  

    Entropy rate is a real valued functional on the space of discrete random sources for which it exists. However, it lacks existence proofs and/or closed formulas even for classes of random sources which have intuitive parameterizations. A good way to overcome this problem is to examine its analytic properties relative to some reasonable topology. A canonical choice of a topology is that of the norm ... View full abstract»

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  • Fairness in Multiuser Systems With Polymatroid Capacity Region

    Publication Year: 2009 , Page(s): 2128 - 2138
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (265 KB) |  | HTML iconHTML  

    For a wide class of multiuser systems, a subset of capacity region which includes the corner points and the sum-capacity facet has a special structure known as polymatroid. Multiple-access channels with fixed input distributions and multiple-antenna broadcast channels are examples of such systems. Any interior point of the sum-capacity facet can be achieved by time-sharing among corner points or b... View full abstract»

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  • The Error Exponent of Variable-Length Codes Over Markov Channels With Feedback

    Publication Year: 2009 , Page(s): 2139 - 2160
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (526 KB) |  | HTML iconHTML  

    The error exponent of Markov channels with feedback is studied in the variable-length block-coding setting. Burnashev's classic result is extended to finite-state ergodic Markov channels. For these channels, a single-letter characterization of the reliability function is presented, under the assumption of full causal output feedback, and full causal observation of the channel state both at the tra... View full abstract»

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  • On the Discrete Memoryless Partially Cooperative Relay Broadcast Channel and the Broadcast Channel With Cooperating Decoders

    Publication Year: 2009 , Page(s): 2161 - 2182
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (495 KB) |  | HTML iconHTML  

    We derive two inner bounds on the rate region of the partially cooperative relay broadcast channel. The first inner bound is based on the Cover and El Gamal generalized strategy for the original relay channel, while the second inner bound is based on the strategy proposed recently by Chong, Motani, and Garg, for the relay channel, which combines backward decoding and simultaneous decoding. Both ra... View full abstract»

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  • Sharp Thresholds for High-Dimensional and Noisy Sparsity Recovery Using \ell _{1} -Constrained Quadratic Programming (Lasso)

    Publication Year: 2009 , Page(s): 2183 - 2202
    Cited by:  Papers (132)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (744 KB) |  | HTML iconHTML  

    The problem of consistently estimating the sparsity pattern of a vector beta* isin Rp based on observations contaminated by noise arises in various contexts, including signal denoising, sparse approximation, compressed sensing, and model selection. We analyze the behavior of l1-constrained quadratic programming (QP), also referred to as the Lasso, for recovering the sparsity ... View full abstract»

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  • Restricted Isometry Constants Where \ell ^{p} Sparse Recovery Can Fail for 0\ll p \leq 1

    Publication Year: 2009 , Page(s): 2203 - 2214
    Cited by:  Papers (32)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (502 KB) |  | HTML iconHTML  

    This paper investigates conditions under which the solution of an underdetermined linear system with minimal lscrp norm, 0 < p les 1, is guaranteed to be also the sparsest one. Matrices are constructed with restricted isometry constants (RIC) delta2m arbitrarily close to 1/radic2 ap 0.707 where sparse recovery with p = 1 fails for at least one m-sparse vector, as well as m... View full abstract»

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  • Weighted Superimposed Codes and Constrained Integer Compressed Sensing

    Publication Year: 2009 , Page(s): 2215 - 2229
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (300 KB) |  | HTML iconHTML  

    We introduce a new family of codes, termed weighted superimposed codes (WSCs). This family generalizes the class of Euclidean superimposed codes (ESCs), used in multiuser identification systems. WSCs allow for discriminating all bounded, integer-valued linear combinations of real-valued codewords that satisfy prescribed norm and nonnegativity constraints. By design, WSCs are inherently noise toler... View full abstract»

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  • Subspace Pursuit for Compressive Sensing Signal Reconstruction

    Publication Year: 2009 , Page(s): 2230 - 2249
    Cited by:  Papers (339)  |  Patents (6)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (976 KB) |  | HTML iconHTML  

    We propose a new method for reconstruction of sparse signals with and without noisy perturbations, termed the subspace pursuit algorithm. The algorithm has two important characteristics: low computational complexity, comparable to that of orthogonal matching pursuit techniques when applied to very sparse signals, and reconstruction accuracy of the same order as that of linear programming (LP) opti... View full abstract»

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  • Model Space Results for the Gabor and Wavelet Transforms

    Publication Year: 2009 , Page(s): 2250 - 2259
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (235 KB) |  | HTML iconHTML  

    We prove that the unique Gabor window leading to an analytic model space is the Gaussian one, and we give an analogous result for the wavelet transform. For the general case we give a new approach to study irregular Gabor and wavelet frames. We improve some known results for Gabor windows in the Feichtinger algebra, and for a special class of wavelets. View full abstract»

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Aims & Scope

IEEE Transactions on Information Theory publishes papers concerned with the transmission, processing, and utilization of information.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Frank R. Kschischang

Department of Electrical and Computer Engineering