IEEE Transactions on Information Theory

Volume 46 Issue 4 • July 2000

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Displaying Results 1 - 25 of 58
  • Finding the permutation between equivalent linear codes: the support splitting algorithm

    Publication Year: 2000, Page(s):1193 - 1203
    Cited by:  Papers (28)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (290 KB)

    Two linear codes are permutation-equivalent if they are equal up to a fixed permutation on the codeword coordinates. We present here an algorithm able to compute this permutation. It operates by determining a set of properties invariant by permutation, one for each coordinate, called a signature. If this signature is fully discriminant-i.e., different for all coordinates-the support of the code sp... View full abstract»

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  • Network information flow

    Publication Year: 2000, Page(s):1204 - 1216
    Cited by:  Papers (4958)  |  Patents (89)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (335 KB)

    We introduce a new class of problems called network information flow which is inspired by computer network applications. Consider a point-to-point communication network on which a number of information sources are to be multicast to certain sets of destinations. We assume that the information sources are mutually independent. The problem is to characterize the admissible coding rate region. This m... View full abstract»

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  • Weak variable-length source coding

    Publication Year: 2000, Page(s):1217 - 1226
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (317 KB)

    Given a general source X={X/sup n/}/sub n=1//sup /spl infin//, source coding is characterized by a pair (/spl phi//sub n/, /spl psi//sub n/) of encoder /spl phi//sub n/, and decoder /spl psi//sub n/, together with the probability of error /spl epsi//sub n//spl equiv/Pr{/spl psi//sub n/(/spl phi//sub n/(X/sup n/))/spl ne/X/sup n/}. If the length of the encoder output /spl phi//sub n/(X/sup n/) is f... View full abstract»

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  • Universal lossless compression via multilevel pattern matching

    Publication Year: 2000, Page(s):1227 - 1245
    Cited by:  Papers (40)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (479 KB)

    A universal lossless data compression code called the multilevel pattern matching code (MPM code) is introduced. In processing a finite-alphabet data string of length n, the MPM code operates at O(log log n) levels sequentially. At each level, the MPM code detects matching patterns in the input data string (substrings of the data appearing in two or more nonoverlapping positions). The matching pat... View full abstract»

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  • A probabilistic approach to some asymptotics in noiseless communication

    Publication Year: 2000, Page(s):1246 - 1262
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (479 KB)

    Renewal theory is a powerful tool in the analysis of source codes. We use renewal theory to obtain some asymptotic properties of finite-state noiseless channels. We discuss the relationship between these results and earlier uses of renewal theory to analyze the Lempel-Ziv (1977, 1978) codes and the Tunstall (1967) code. As a new application of our results, we provide the asymptotic performance of ... View full abstract»

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  • Duality theorems for joint source-channel coding

    Publication Year: 2000, Page(s):1263 - 1275
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (378 KB)

    We consider joint source-channel coding for a memoryless Gaussian source and an additive white Gaussian noise (AWGN) channel. For a given code defined by an encoder-decoder pair (/spl alpha/, /spl beta/), its dual code is obtained by interchanging the encoder and decoder: (/spl beta/, /spl alpha/). It is shown that if a code (/spl alpha/, /spl beta/) is optimal at rate p channel uses per source sa... View full abstract»

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  • Bounds on the a priori index crossover probabilities for trellis-based channel codes

    Publication Year: 2000, Page(s):1276 - 1291
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (372 KB)

    This paper derives truncated union bounds on the a priori index crossover probabilities p(j|i) that result when an n-bit data index i is convolutionally encoded, transmitted over a noisy channel, and decoded with the Viterbi algorithm, giving received index j. The bounds are derived with a modified transfer function technique, using n-stage state transition matrices with symbolic labels. The techn... View full abstract»

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  • Two-dimensional weight-constrained codes through enumeration bounds

    Publication Year: 2000, Page(s):1292 - 1301
    Cited by:  Papers (19)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (340 KB)

    For a rational /spl alpha//spl isin/(0,1), let /spl Ascr//sub n/spl times/m,/spl alpha// be the set of binary n/spl times/m arrays in which each row has Hamming weight /spl alpha/m and each column has Hamming weight /spl alpha/n, where /spl alpha/m and /spl alpha/n are integers. (The special case of two-dimensional balanced arrays corresponds to /spl alpha/=1/2 and even values for n and m.) The re... View full abstract»

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  • Nested input-constrained codes

    Publication Year: 2000, Page(s):1302 - 1316
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (393 KB)

    An input-constrained channel, or simply a constraint, is a set S of words that is generated by a finite labeled directed graph. An encoder for S maps, in a lossless manner, sequences of unconstrained input blocks into sequences of channel blocks, the latter sequences being words of S. In most applications, the encoders are finite-state machines and, thus, presented by state diagrams. In the specia... View full abstract»

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  • On quantum fidelities and channel capacities

    Publication Year: 2000, Page(s):1317 - 1329
    Cited by:  Papers (119)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (274 KB)

    For the discrete memoryless quantum channel, we show the equivalence of two different notions of quantum channel capacity: that which uses the entanglement fidelity as its criterion for success in transmission, and that which uses the minimum fidelity of pure states in a subspace of the input Hilbert space as its criterion. As a corollary, any source with entropy rate less than the capacity may be... View full abstract»

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  • Chinese remaindering with errors

    Publication Year: 2000, Page(s):1330 - 1338
    Cited by:  Papers (60)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (224 KB)

    The Chinese remainder theorem states that a positive integer m is uniquely specified by its remainder module k relatively prime integers p/sub 1/, /spl middot//spl middot//spl middot/, p/sub k/, provided m</spl Pi//sub i=1//sup k/p/sub i/. Thus the residues of m module relatively prime integers p/sub 1/<p/sub 2/</spl middot//spl middot//spl middot/<p/sub n/ form a redundant representat... View full abstract»

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  • Cryptanalysis of RSA with private key d less than N/sup 0.292/

    Publication Year: 2000, Page(s):1339 - 1349
    Cited by:  Papers (94)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (351 KB)

    We show that if the private exponent d used in the RSA (Rivest-Shamir-Adleman (1978)) public-key cryptosystem is less than N/sup 0.292/ then the system is insecure. This is the first improvement over an old result of Wiener (1990) showing that when d is less than N/sup 0.25/ the RSA system is insecure. We hope our approach can be used to eventually improve the bound to d less than N/sup 0.5/. View full abstract»

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  • Authentication theory and hypothesis testing

    Publication Year: 2000, Page(s):1350 - 1356
    Cited by:  Papers (71)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (134 KB)

    By interpreting message authentication as a hypothesis testing problem, this paper provides a generalized treatment of information-theoretic lower bounds on an opponent's probability of cheating in one-way message authentication. We consider the authentication of an arbitrary sequence of messages, using the same secret key shared between sender and receiver. The adversary tries to deceive the rece... View full abstract»

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  • Performance analysis of hypothesis testing for sparse pairwise interaction point processes

    Publication Year: 2000, Page(s):1357 - 1365
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (204 KB)

    The sufficient statistic for performing the likelihood ratio test for pairwise interaction point processes is well-known; however, the evaluation of its performance is a very difficult problem. It is shown that the distribution of the sufficient statistic can be approximated by the distribution of a Poisson-driven shot-noise random variable, which can be readily computed. View full abstract»

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  • Multihypothesis sequential probability ratio tests. II. Accurate asymptotic expansions for the expected sample size

    Publication Year: 2000, Page(s):1366 - 1383
    Cited by:  Papers (65)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (655 KB)

    For pt. I see ibid. vol.45, p.2448-61, 1999. We proved in pt.I that two specific constructions of multihypothesis sequential tests, which we refer to as multihypothesis sequential probability ratio tests (MSPRTs), are asymptotically optimal as the decision risks (or error probabilities) go to zero. The MSPRTs asymptotically minimize not only the expected sample size but also any positive moment of... View full abstract»

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  • Capacity and mutual information of wideband multipath fading channels

    Publication Year: 2000, Page(s):1384 - 1400
    Cited by:  Papers (202)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (441 KB)

    We investigate the capacity and mutual information of a broadband fading channel consisting of a finite number of time-varying paths. We show that the capacity of the channel in the wideband limit is the same as that of a wideband Gaussian channel with the same average received power. However, the input signals needed to achieve the capacity must be "peaky" in time or frequency. In particular, we ... View full abstract»

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  • Shannon-theoretic approach to a Gaussian cellular multiple-access channel with fading

    Publication Year: 2000, Page(s):1401 - 1425
    Cited by:  Papers (134)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (731 KB)

    Shannon-theoretic limits on the achievable throughput for a simple infinite cellular multiple-access channel (MAC) model (Wyner 1994) in the presence of fading are presented. In this model, which is modified to account for flat fading, the received signal, at a given cell-site's antenna, is the sum of the faded signals transmitted from all users within that cell plus an attenuation factor /spl alp... View full abstract»

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  • Effective interference and effective bandwidth of linear multiuser receivers in asynchronous CDMA systems

    Publication Year: 2000, Page(s):1426 - 1447
    Cited by:  Papers (79)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (469 KB)

    The performance of linear multiuser receivers in terms of the signal-to-interference ratio (SIR) achieved by the users has been analyzed in a synchronous CDMA system under random spreading sequences. In this paper, we extend these results to a symbol-asynchronous but chip-synchronous system and characterize the SIR for linear receivers-the matched-filter receiver the minimum mean-square error (MMS... View full abstract»

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  • Multiple-access interference reduction for QS-CDMA systems with a novel class of polyphase sequences

    Publication Year: 2000, Page(s):1448 - 1458
    Cited by:  Papers (31)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (341 KB)

    In this paper, a new class of polyphase sequences for CDMA systems and its generation method are suggested, and the correlation properties of the sequence are investigated. The performance of the sequence in quasi-synchronous CDMA (QS-CDMA) systems is investigated under a frequency-selective, time-nonselective, slow Nakagami fading channel with additive white Gaussian noise (AWGN). It is shown tha... View full abstract»

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  • Near-optimal limited-search detection on ISI/CDMA channels and decoding of long convolutional codes

    Publication Year: 2000, Page(s):1459 - 1482
    Cited by:  Papers (16)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (655 KB)

    We derive an upper bound on the bit-error probability (BEP) in limited-search detection over a finite interference channel. A unified channel model is presented; this includes finite-length intersymbol interference channels and multiuser CDMA channels as two special cases. We show that the BEP of the M-algorithm (MA) is bounded from above by the sum of three terms: an upper bound on the error prob... View full abstract»

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  • Theoretical analysis and performance limits of noncoherent sequence detection of coded PSK

    Publication Year: 2000, Page(s):1483 - 1494
    Cited by:  Papers (19)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (322 KB)

    A theoretical performance analysis of noncoherent sequence detection schemes previously proposed by the authors for combined detection and decoding of coded M-ary phase-shift keying (M-PSK) is presented. A method for the numerical evaluation of the pairwise error probability-for which no closed-form expressions exist-is described, the classical union bound is computed, and results are compared wit... View full abstract»

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  • A note on type II convolutional codes

    Publication Year: 2000, Page(s):1510 - 1514
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (139 KB)

    The result of a search for the world's second type II (doubly-even and self-dual) convolutional code is reported. A rate R=4/8, 16-state, time-invariant, convolutional code with free distance d/sub free/=8 was found to be type II. The initial part of its weight spectrum is better than that of the Golay convolutional code (GCC). Generator matrices and path weight enumerators for some other type II ... View full abstract»

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  • Linear tail-biting trellises, the square-root bound, and applications for Reed-Muller codes

    Publication Year: 2000, Page(s):1514 - 1523
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (371 KB)

    Linear tail-biting trellises for block codes are considered. By introducing the notions of subtrellis, merging interval, and sub-tail-biting trellis, some structural properties of linear tail-biting trellises are proved. It is shown that a linear tail-biting trellis always has a certain simple structure, the parallel-merged-cosets structure. A necessary condition required from a linear code in ord... View full abstract»

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  • Bounds on the state complexity of codes from the Hermitian function field and its subfields

    Publication Year: 2000, Page(s):1523 - 1527
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (208 KB)

    An upper bound on the minimal state complexity of codes from the Hermitian function field and some of its subfields is derived. Coordinate orderings under which the state complexity of the codes is not above the bound are specified. For the self-dual Hermitian code it is proved that the bound coincides with the minimal state complexity of the code. Finally, it is shown that Hermitian codes over fi... View full abstract»

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  • A class of linear codes with good parameters from algebraic curves

    Publication Year: 2000, Page(s):1527 - 1532
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (249 KB)

    A class of linear codes with good parameters is constructed in this correspondence. It turns out that linear codes of this class are subcodes of the subfield subcodes of Goppa's geometry codes. In particular, we find 61 improvements on Brouwer's table based on our codes. 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
Alexander Barg

Department of Electrical and Computer Engineering and the Institute for Systems Research, University of Maryland

email: abarg-ittrans@ece.umd.edu