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IEEE Transactions on Information Theory

Issue 5 • July 1999

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Displaying Results 1 - 25 of 45
  • On the weight distribution of terminated convolutional codes

    Publication Year: 1999, Page(s):1646 - 1648
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (98 KB)

    In this correspondence, the low-weight terms of the weight distribution of the block code obtained by terminating a convolutional code after x information blocks are expressed as a function of x. It is shown that this function is linear in x for codes with noncatastrophic encoders, but quadratic in x for codes with catastrophic encoders. These results are useful to explain the poor performance of ... View full abstract»

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  • Contributors

    Publication Year: 1999, Page(s):1742 - 1751
    Request permission for commercial reuse | PDF file iconPDF (78 KB)
    Freely Available from IEEE
  • A characterization of 1-perfect additive codes

    Publication Year: 1999, Page(s):1688 - 1697
    Cited by:  Papers (33)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (364 KB)

    The characterization of perfect single error-correcting codes, or 1 perfect codes, has been an open question for a long time. Recently, Rifa has proved that a binary 1-perfect code can be viewed as a distance-compatible structure in Fn and a homomorphism θ:Fn→Ω where Ω is a loop (a quasi-group with identity element). In this correspondence, we consider ... View full abstract»

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  • Multiple ramp schemes

    Publication Year: 1999, Page(s):1720 - 1728
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (288 KB)

    A (t,k,n,S) ramp scheme is a protocol to distribute a secret s chosen in S among a set P of n participants in such a way that: (1) sets of participants of cardinality greater than or equal to k can reconstruct the secret s; (2) sets of participants of cardinality less than or equal to t have no information on s, whereas (3) sets of participants of cardinality greater than t and less than k might h... View full abstract»

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  • The Preparata and Goethals codes: trellis complexity and twisted squaring constructions

    Publication Year: 1999, Page(s):1667 - 1673
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (240 KB)

    The trellis complexity of the Preparata and Goethals codes is examined. It is shown that at least for a given set of permutations these codes are rectangular. Upper bounds on the state complexity profiles of the Preparata and Goethals codes are given. The upper bounds on the state complexity of the Preparata and Goethals codes are determined by the dimension/length profiles (DLP) of the extended p... View full abstract»

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  • New ternary linear codes

    Publication Year: 1999, Page(s):1687 - 1688
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (108 KB)

    Let [n,k,d;q]-codes be linear codes of length n, dimension k, and minimum Hamming distance d over GF(q). In this correspondence, 18 codes are constructed which improve the known lower bounds on minimum distance View full abstract»

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  • A new look at entropy for solving linear inverse problems

    Publication Year: 1999, Page(s):1565 - 1578
    Cited by:  Papers (24)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (468 KB)

    Entropy-based methods are widely used for solving inverse problems, particularly when the solution is known to be positive. Here, we address linear ill-posed and noisy inverse problems of the form z=Ax+n with a general convex constraint x∈X, where X is a convex set. Although projective methods are well adapted to this context, we study alternative methods which rely highly on some “info... View full abstract»

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  • Efficient digital-to-analog encoding

    Publication Year: 1999, Page(s):1551 - 1554
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (88 KB)

    An important issue in analog circuit design is the problem of digital-to-analog conversion, i.e., the encoding of Boolean variables into a single analog value which contains enough information to reconstruct the values of the Boolean variables. A natural question is: what is the complexity of implementing the digital-to-analog encoding function? That question was answered by Wegener (see Inform. P... View full abstract»

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  • The Tate pairing and the discrete logarithm applied to elliptic curve cryptosystems

    Publication Year: 1999, Page(s):1717 - 1719
    Cited by:  Papers (61)  |  Patents (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (124 KB)

    The Tate pairing is used to reduce the discrete logarithm (DL) problem on certain elliptic curves to the DL in the multiplicative group of finite fields View full abstract»

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  • The weighted coordinates bound and trellis complexity of block codes and periodic packings

    Publication Year: 1999, Page(s):1658 - 1667
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (312 KB)

    Weighted entropy profiles and a new bound, the weighted coordinates bound, on the state complexity profile of block codes are presented. These profiles and bound generalize the notion of dimension/length profile (DLP) and entropy/length profile (ELF) to block codes whose symbols are not drawn from a common alphabet set, and in particular, group codes. Likewise, the new bound may improve upon the D... View full abstract»

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  • On the composition of Tunstall messages

    Publication Year: 1999, Page(s):1608 - 1612
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (176 KB)

    We study the composition of messages in an encoding tree for a Tunstall code, and, more generally, in a tree whose skewness is bounded. For such trees a sort of “law of large numbers” holds true; actually, we provide a direct and converse coding theorem for variable-length to block length source codes, when a vanishing error probability is allowed View full abstract»

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  • On the capacity of two-dimensional run-length constrained channels

    Publication Year: 1999, Page(s):1527 - 1540
    Cited by:  Papers (71)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (800 KB)

    Two-dimensional binary patterns that satisfy one-dimensional (d, k) run-length constraints both horizontally and vertically are considered. For a given d and k, the capacity Cd,k is defined as Cd,k=limm,n→∞log2Nm,n d,k/mn, where Nm,nd,k denotes the number of m×n rectangular patterns that satisf... View full abstract»

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  • How to overcome the curse of long-memory errors

    Publication Year: 1999, Page(s):1735 - 1741
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (264 KB)

    Long-memory errors dramatically slow down the convergence of minimax risks in a fixed design nonparametric regression. The problem becomes even more complicated for the case of adaptive estimation. This defines the curse of long-memory errors. I show that using a random design, instead of a fixed one, allows one to overcome this curse and make familiar data-driven estimators robust. Moreover, the ... View full abstract»

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  • Minimum rate sampling and reconstruction of signals with arbitrary frequency support

    Publication Year: 1999, Page(s):1555 - 1564
    Cited by:  Papers (55)  |  Patents (17)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (212 KB)

    We examine the question of reconstruction of signals from periodic nonuniform samples. This involves discarding samples from a uniformly sampled signal in some periodic fashion. We give a characterization of the signals that can be reconstructed at exactly the minimum rate once a nonuniform sampling pattern has been fixed. We give an implicit characterization of the reconstruction system, and a de... View full abstract»

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  • Distortion bounds for vector quantizers with finite codebook size

    Publication Year: 1999, Page(s):1621 - 1631
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (448 KB)

    Upper and lower bounds are presented for the distortion of the optimal N-point vector quantizer applied to k-dimensional signals. Under certain smoothness conditions on the source distribution, the bounds are shown to hold for each and every value of N, the codebook size. These results extend bounds derived in the high-resolution limit, which assume that the number of code vectors is arbitrarily l... View full abstract»

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  • Multilevel codes: theoretical concepts and practical design rules

    Publication Year: 1999, Page(s):1361 - 1391
    Cited by:  Papers (472)  |  Patents (57)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (720 KB)

    This paper deals with 2l-ary transmission using multilevel coding (MLC) and multistage decoding (MSD). The known result that MLC and MSD suffice to approach capacity if the rates at each level are appropriately chosen is reviewed. Using multiuser information theory, it is shown that there is a large space of rate combinations such that MLC and full maximum-likelihood decoding (MLD) can ... View full abstract»

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  • A universal lattice code decoder for fading channels

    Publication Year: 1999, Page(s):1639 - 1642
    Cited by:  Papers (1002)  |  Patents (84)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (128 KB)

    We present a maximum-likelihood decoding algorithm for an arbitrary lattice code when used over an independent fading channel with perfect channel state information at the receiver. The decoder is based on a bounded distance search among the lattice points falling inside a sphere centered at the received point. By judicious choice of the decoding radius we show that this decoder can be practically... View full abstract»

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  • Performance analysis of a decoding algorithm for algebraic-geometry codes

    Publication Year: 1999, Page(s):1712 - 1717
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (240 KB)

    The fast decoding algorithm for one point algebraic-geometry codes of Sakata, Elbrond Jensen, and Hoholdt (see ibid., vol. 41, p. 1762-8, Nov. 1995) corrects all error patterns of weight less than half the Feng-Rao minimum distance. In this correspondence we analyze the performance of the algorithm for heavier error patterns. It turns out that in the typical case, where the error points are &ldquo... View full abstract»

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  • New rate 1/2, 1/3, and 1/4 binary convolutional encoders with an optimum distance profile

    Publication Year: 1999, Page(s):1653 - 1658
    Cited by:  Papers (4)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (228 KB)

    Tabulations of binary systematic and nonsystematic polynomial convolutional encoders with an optimum distance profile for rate 1/2, 1/3, and 1/4 are given. The reported encoders are found by computer searches that optimize over the weight spectra. The free distances for rate 1/3 and 1/4 are compared with Heller's (1968) and Griesmer's (1960) upper bounds View full abstract»

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  • Constructions and families of nonbinary linear codes with covering radius 2

    Publication Year: 1999, Page(s):1679 - 1686
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (380 KB)

    New constructions of linear nonbinary codes with covering radius R=2 are proposed. They are in part modifications of earlier constructions by the author and in part are new. Using a starting code with R=2 as a “seed” these constructions yield an infinite family of codes with the same covering radius. New infinite families of codes with R=2 are obtained for all alphabets of size q⩾4... View full abstract»

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  • Spatially correlated qubit errors and burst-correcting quantum codes

    Publication Year: 1999, Page(s):1703 - 1708
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (232 KB)

    We explore the design of quantum error-correcting codes for cases where the decoherence events of qubits are correlated. In particular, we consider the case where only spatially contiguous qubits decohere, which is analogous to the case of burst errors in classical coding theory. We present several different efficient schemes for constructing families of such codes. For example, one can find one-d... View full abstract»

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  • The entropy of traces in parallel computation

    Publication Year: 1999, Page(s):1606 - 1608
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (120 KB)

    The following problem arises in the context of parallel computation: how many bits of information are required to specify any one element from an arbitrary (non-empty) k-subset of a set? We characterize optimal coding techniques for this problem. We calculate the asymptotic behavior of the amount of information necessary, and construct an algorithm that specifies an element from a subset in an opt... View full abstract»

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  • A semi-continuous version of the Berger-Yeung problem

    Publication Year: 1999, Page(s):1520 - 1526
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (204 KB)

    We present a continuous dual of multiterminal source encoding with one distortion criterion (the “Berger-Yeung (1989) problem”). A continuous source X is encoded with “high resolution” (Dx→0), with the aid of a “helper,” i.e., a correlated discrete or continuous source Y, that is encoded separately subject to some arbitrary distortion criterion D... View full abstract»

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  • Optimum power control over fading channels

    Publication Year: 1999, Page(s):1468 - 1489
    Cited by:  Papers (511)  |  Patents (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (632 KB)

    We study optimal constant-rate coding schemes for a block-fading channel with strict transmission delay constraint, under the assumption that both the transmitter and the receiver have perfect channel-state information. We show that the information outage probability is minimized by concatenating a standard “Gaussian” code with an optimal power controller, which allocates the transmitt... View full abstract»

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  • On the non Z4-linearity of certain good binary codes

    Publication Year: 1999, Page(s):1674 - 1677
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (140 KB)

    In this correspondence we prove that any extremal doubly-even self-dual linear binary code of length 48 is not Z4-linear. We also show that the putative extremal doubly-even self-dual linear binary codes of lengths 72 and 96 with minimum weight, respectively, 16 and 20, cannot be constructed as the Gray images of linear codes over Z4 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