IEEE Transactions on Information Theory

Issue 4 • Jul 1993

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Displaying Results 1 - 25 of 41
  • Further asymptotic upper bounds on the minimum distance of trellis codes

    Publication Year: 1993, Page(s):1428 - 1431
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (360 KB)

    Asymptotic upper bounds on the minimum distance of trellis codes are derived. A universal bound and bounds specific to phase-shift keying (PSK) and quadrature amplitude modulation (QAM) signal sets are obtained View full abstract»

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  • A relation between Levenshtein-type distances and insertion-and-deletion correcting capabilities of codes

    Publication Year: 1993, Page(s):1424 - 1427
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (352 KB)

    A code is a collection of words or strings, not necessarily all of the same length, over come fixed alphabet. A relation is established between the insertion-and-deletion correcting capability of a code and its minimum distance for suitable Levenshtein-type distance measures View full abstract»

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  • Some new lower bounds for binary and ternary covering codes

    Publication Year: 1993, Page(s):1422 - 1424
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (228 KB)

    A modified lower bound for binary codes with covering radius one is derived. Let Kq(n,R) denote the minimum cardinality of a q-ary code with covering radius R . The new bound shows that K2(11,1)⩾177 and that K2(17,1)⩾7391, improvements of the best lower bounds known. The authors also generalize ... View full abstract»

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  • On the capacity of a cascade of channels

    Publication Year: 1993, Page(s):1310 - 1321
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1008 KB)

    A class of information-theoretic problems is introduced that deals with systems in which information is transmitted through a series of noisy channels with limited or no processing between channels. Some basic questions that arise in such systems are examined in detail. The effects of ordering of the channels on overall capacity and the characteristics that cause channels to have high capacity whe... View full abstract»

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  • On the design of an optimal quantizer

    Publication Year: 1993, Page(s):1180 - 1194
    Cited by:  Papers (11)  |  Patents (22)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1312 KB)

    The problem of designing an optimal quantizer with a fixed number of levels for a wide class of error weighting functions and an arbitrary distribution function is discussed. The existence of an optimal quantizer is proved, and a two-stage algorithm for its design is suggested. In this algorithm, at the first stage, Lloyd's iterative Method I is applied for reducing the region where, at the second... View full abstract»

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  • The entropy of Markov trajectories

    Publication Year: 1993, Page(s):1418 - 1421
    Cited by:  Papers (24)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (244 KB)

    The idea of thermodynamic depth put forth by S. Lloyd and H. Pagels (1988) requires the computation of the entropy of Markov trajectories. Toward this end, the authors consider an irreducible finite state Markov chain with transition matrix P and associated entropy rate H(X)=-Σi,j μiPij log Pij where ... View full abstract»

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  • A measure of relative entropy between individual sequences with application to universal classification

    Publication Year: 1993, Page(s):1270 - 1279
    Cited by:  Papers (63)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (744 KB)

    A new notion of empirical informational divergence (relative entropy) between two individual sequences is introduced. If the two sequences are independent realizations of two finite-order, finite alphabet, stationary Markov processes, the empirical relative entropy converges to the relative entropy almost surely. This empirical divergence is based on a version of the Lempel-Ziv data compression al... View full abstract»

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  • A coding scheme for single peak-shift correction in (d, k)-constrained channels

    Publication Year: 1993, Page(s):1444 - 1450
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (712 KB)

    A two step coding scheme for peak-shift correction in (d, k)-constrained sequences is described. The first step is based on q-ary (q=k-d+1 is a prime) block codes that allow correction of specific types of double errors caused by single peak-shifts. The second step is a simple conversion of q-ary symbols to binary strings of the type 0... View full abstract»

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  • Sliding block codes between constrained systems

    Publication Year: 1993, Page(s):1303 - 1309
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (620 KB)

    The construction of finite-state codes between constrained systems called sofic systems introduced by R. Karabed and B. Marcus (1988) is continued. It is shown that if Σ is a shift of finite type and S is a sofic system with k/n=h(S )/h(Σ), where h denotes entropy, there is a noncatastrophic finite-state invertible code fro... View full abstract»

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  • Alphabet-constrained vector quantization

    Publication Year: 1993, Page(s):1167 - 1179
    Cited by:  Papers (9)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1100 KB)

    Alphabet-constrained rate-distortion theory is extended to coding of sources with memory. Two different cases are considered: when only the size of the codebook is constrained and when the codevector values are also held fixed. For both cases, nth-order constrained-alphabet rate-distortion functions are defined and a convergent algorithm for their evaluation is presented. Specific simulat... View full abstract»

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  • Asymptotic results for maximum likelihood estimation with an array of sensors

    Publication Year: 1993, Page(s):1374 - 1385
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1004 KB)

    In many cases, the maximum likelihood (ML) estimator is consistent and asymptotically normal with covariance equal to the inverse of the Fisher's information matrix. It does not follow, though, that the covariance of the ML estimator approaches the Cramer-Rao lower bound as the sample size increases. However, it is possible to draw such a conclusion for the adaptive array problem in which directio... View full abstract»

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  • The maximal error capacity of arbitrarily varying channels for constant list sizes

    Publication Year: 1993, Page(s):1416 - 1417
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (168 KB)

    The capacity of an arbitrarily varying channel (AVC) for list codes of arbitrarily small list rate under the maximal error criterion has previously been determined. The authors prove that for an AVC A , any rate R below the list code capacity C1 (A) is achievable with a particular list size dependent on A, R and Y, where View full abstract»

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  • Universal decoding for memoryless Gaussian channels with a deterministic interference

    Publication Year: 1993, Page(s):1261 - 1269
    Cited by:  Papers (30)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (612 KB)

    A universal decoding procedure is proposed for memoryless Gaussian channels with deterministic interfering signals from a certain class. The proposed decoder is universal in the sense that it is independent of the channel parameters and the unknown interfering signal, and, at the same time, attains the same random coding error exponent as the optimal maximum likelihood (ML) decoder, which utilizes... View full abstract»

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  • Maximum likelihood decoding of the Leech lattice

    Publication Year: 1993, Page(s):1435 - 1444
    Cited by:  Papers (26)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (804 KB)

    An algorithm for maximum likelihood decoding of the Leech lattice is presented. The algorithm involves projecting the points of the Leech lattice directly onto the codewords of the (6,3,4) quaternary code-the hexacode. Projection on the hexacode induces a partition of the Leech lattice into four cosets of a certain sublattice 24. Such a partition into cosets enables maximum likelihood decoding of ... View full abstract»

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  • Proper complex random processes with applications to information theory

    Publication Year: 1993, Page(s):1293 - 1302
    Cited by:  Papers (499)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (824 KB)

    The covariance of complex random variables and processes, when defined consistently with the corresponding notion for real random variables, is shown to be determined by the usual complex covariance together with a quantity called the pseudo-covariance. A characterization of uncorrelatedness and wide-sense stationarity in terms of covariance and pseudo-covariance is given. Complex random variables... View full abstract»

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  • Wavelet transforms associated with finite cyclic groups

    Publication Year: 1993, Page(s):1157 - 1166
    Cited by:  Papers (44)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (824 KB)

    Multiresolution analysis via decomposition on wavelet bases has emerged as an important tool in the analysis of signals and images when these objects are viewed as sequences of complex or real numbers. An important class of multiresolution decompositions are the Laplacian pyramid schemes, in which the resolution is successively halved by recursively low-pass filtering the signal under analysis and... View full abstract»

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  • Strong universal consistency of neural network classifiers

    Publication Year: 1993, Page(s):1146 - 1151
    Cited by:  Papers (28)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (496 KB)

    In statistical pattern recognition, a classifier is called universally consistent if its error probability converges to the Bayes-risk as the size of the training data grows for all possible distributions of the random variable pair of the observation vector and its class. It is proven that if a one-layered neural network with properly chosen number of nodes is trained to minimize the empirical ri... View full abstract»

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  • Markov modeling for Bayesian restoration of two-dimensional layered structures

    Publication Year: 1993, Page(s):1356 - 1373
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1612 KB)

    Bayesian estimation of two-dimensional stratified structures is described. The major point addressed is the derivation of a statistical prior model that adequately describes such layered media. This problem is of interest in applications in which the data are generally processed in one dimension only. In order to take local interactions into account, a Markovian description is used. The model is d... View full abstract»

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  • An algorithm for the k-error linear complexity of binary sequences with period 2n

    Publication Year: 1993, Page(s):1398 - 1401
    Cited by:  Papers (78)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (368 KB)

    Certain applications require pseudo-random sequences which are unpredictable in the sense that recovering more of the sequence from a short segment must be computationally infeasible. It is shown that linear complexity is useful in determining such sequences. A generalized linear complexity that has application to the security of stream ciphers is proposed, and an efficient algorithm is given for ... View full abstract»

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  • Common randomness in information theory and cryptography. I. Secret sharing

    Publication Year: 1993, Page(s):1121 - 1132
    Cited by:  Papers (578)  |  Patents (11)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1096 KB)

    As the first part of a study of problems involving common randomness at distance locations, information-theoretic models of secret sharing (generating a common random key at two terminals, without letting an eavesdropper obtain information about this key) are considered. The concept of key-capacity is defined. Single-letter formulas of key-capacity are obtained for several models, and bounds to ke... View full abstract»

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  • Nonbinary codes correcting localized errors

    Publication Year: 1993, Page(s):1413 - 1416
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (332 KB)

    A recursive construction of asymptotically dense codes correcting a constant number of localized errors is examined. The codes overcome difficulties for a particular case with an asymptotic Hamming bound in which the number of errors increases linearly with the length of codes. It is shown that this method is applicable to both binary and nonbinary cases View full abstract»

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  • Correcting dependent errors in sequences generated by finite-state processes

    Publication Year: 1993, Page(s):1249 - 1260
    Cited by:  Papers (16)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1132 KB)

    A new channel model and channel inversion algorithm are presented for correcting symbol sequences that have been corrupted by an unknown combination of known fault mechanisms. The algorithm is similar to the Viterbi algorithm in that it is suitable for situations in which the uncorrupted data string is generated by a known finite-state process, but it is more versatile in that it can correct a muc... View full abstract»

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  • On the nonperiodic cyclic equivalence classes of Reed-Solomon codes

    Publication Year: 1993, Page(s):1431 - 1434
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (352 KB)

    Picking up exactly one member from each of the nonperiodic cyclic equivalence classes of an (n, k+1) Reed-Solomon code E over GF(q) gives a code, E", which has bounded Hamming correlation values and the self-synchronizing property. The exact size of E" is shown to be (1/n) Σd|n μ(d)q1+kd... View full abstract»

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  • Partition function estimation of Gibbs random field images using Monte Carlo simulations

    Publication Year: 1993, Page(s):1322 - 1332
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (864 KB)

    A Monte Carlo simulation technique for estimating the partition function of a general Gibbs random field image is proposed. By expressing the partition function as an expectation, an importance sampling approach for estimating it using Monte Carlo simulations is developed. As expected, the resulting estimators are unbiased and consistent. Computations can be performed iteratively by using simple M... View full abstract»

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  • Covering radius, codimension, and dual-distance width

    Publication Year: 1993, Page(s):1195 - 1203
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (544 KB)

    Upper bounds on the covering radius of codes with a given cardinality and a given dual-distance width are derived. Using an entirely new method, some results published by C. Delorme and P. Sole (1991) for linear codes are generalized, and results are derived for unrestricted codes that have no previous analogue. For some classes of codes, when the parameters lie within certain intervals, results i... 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.

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Meet Our Editors

Editor-in-Chief
Prakash Narayan 

Department of Electrical and Computer Engineering