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1998 Information Theory Workshop (Cat. No.98EX131)

22-26 June 1998

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  • 1998 Information Theory Workshop (Cat. No.98EX131)

    Publication Year: 1998
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  • Mixture models achieving optimal coding regret

    Publication Year: 1998
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (63 KB)

    Summary form only given. The relative entropy between the Jeffreys mixture and Shtarkov's normalized maximum likelihood distribution tends to zero as the sample size gets large for smooth parametric families of distributions, and equivalently, the Jeffreys mixture is asymptotically maximin for the coding regret problem. Implications of this fact reveal lower bounds, including explicit constants, t... View full abstract»

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  • MMD codes in a more general sense

    Publication Year: 1998
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (73 KB)

    Summary form only given. The author deals with the characterisation of maximum minimum distance (MMD) codes in a more general sense, which has been completed in a joint work with Olsson. As in the m=1 case the weight distribution of an MMD code /spl Cscr/ is uniquely determined by its parameters [n,k,d]/sub q/. View full abstract»

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  • On the frame error rate of turbo-codes

    Publication Year: 1998, Page(s):118 - 119
    Cited by:  Papers (3)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (262 KB)

    In spite of the excellent bit error rate performance of the original turbo-code, simulations indicate that this code yields relatively poor frame error rate performance. In this paper we show that "primitive" turbo-codes and "asymmetric" turbo-codes provides both good bit error rate and frame error rate performance. View full abstract»

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  • Congestion control and routing in multicasting

    Publication Year: 1998
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (83 KB)

    Summary form only given. The author addresses the problems of congestion control and routing of multicast traffic in communication networks. The network is modeled by an arbitrary topology directed graph G=(V,E) and the capacity of edge e is C/sub e/. A multicast session is identified by the pair (v,S) where v is the source node of the session and S is the group of intended destination nodes. Ther... View full abstract»

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  • Author index

    Publication Year: 1998, Page(s):161 - 162
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    Freely Available from IEEE
  • How to encode a stationary source

    Publication Year: 1998, Page(s):86 - 87
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (160 KB)

    We study the problem of constructing messages of the form ω 1, ω2, ..., where each ωk is a letter from a finite alphabet, so that the statistics of ω 1, ω2, ... correspond to a given stationary probability distribution View full abstract»

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  • Design of context-free grammars for lossless data compression

    Publication Year: 1998, Page(s):84 - 85
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (188 KB)

    Any context-free grammar G generates a language L(G). We are interested in context-free grammars G in which L(G) consists of exactly one string. Given a data string a over a finite alphabet and a context-free grammar G such that L(G)={x} one can reduce G to a simpler grammar G' for which L(G')={x} and for which certain constraints are satisfied. One then losslessly compresses x by losslessly compr... View full abstract»

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  • On cryptographic propagation criteria for Boolean functions

    Publication Year: 1998, Page(s):148 - 149
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (196 KB)

    We characterize those functions on GF(2)n which satisfy the propagation criterion of degree n-2. We give a general construction of nonquadratic functions satisfying the extended propagation criterion of degree l and order k, which uses the existence of nonlinear, systematic codes with good minimum distances and dual distances. We apply it to Kerdock codes and Preparata codes. We also st... View full abstract»

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  • Capacity achieving coding for the “OR” multiple access channel

    Publication Year: 1998, Page(s):126 - 127
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (124 KB)

    We discuss a particular method of random access communications for asynchronous multiple access. We first compare the classical synchronous capacity with the respective asynchronous capacities for three different types of multiuser channels: the OR; the OR with intensity information and the XOR. We assume that the number of active users (inputs) T is large. In particular, we show that for instance... View full abstract»

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  • Maximum likelihood and multistage decoding for optimised multilevel coded modulation

    Publication Year: 1998, Page(s):81 - 82
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (184 KB)

    We consider maximum likelihood trellis decoding of multilevel coded modulation optimised for finite BER. We introduce a class of optimised block coded modulation (BCM) schemes for 8-PSK with a very simple trellis decoder, and show they perform significantly better than conventionally-designed BCM schemes View full abstract»

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  • On epicyclic Hermitian codes

    Publication Year: 1998
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (76 KB)

    The class of Hermitian codes is a popular and well-studied class of codes on planar curves over GF(2m). These codes have large blocklength, and may soon find engineering importance. In contrast to Reed-Solomon codes, which were discovered by engineers, Hermitian codes were introduced by mathematicians as an example of algebraic geometry codes. We re-introduce Hermitian codes as if they ... View full abstract»

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  • Universal sequential decoding

    Publication Year: 1998
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (108 KB)

    An algorithm is proposed for universal decoding of convolutional/trellis codes employed over unknown channels. On discrete memoryless channels and at rates below the computational cut-off rate (corresponding to a uniform input distribution), the algorithm achieves an asymptotic complexity-vs.-performance tradeoff similar to the tradeoff achieved by the Viterbi (1979) algorithm, but with the benefi... View full abstract»

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  • Bounds on the asymptotic buffer overflow probabilities of a parallel processing system

    Publication Year: 1998, Page(s):145 - 146
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (184 KB)

    In queueing systems with heterogeneous processors and multiclass job flows, weighted queue length policies are known to achieve maximal throughput, that is, stabilize the system under the maximum possible arrival rates, when the buffers are of infinite capacity. However, very little is known regarding the delay or buffer overflow performance of weighted queue length policies in such queueing syste... View full abstract»

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  • Trellises and new trellis-based decoding algorithms for codes

    Publication Year: 1998, Page(s):79 - 80
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (232 KB)

    This paper presents the fundamental concepts, basic structures, and construction of trellises for linear codes. It also includes a number of trellis-based decoding algorithms. Particularly, two new decoding algorithms, one for block codes and the other for convolutional codes, are presented. Both algorithms are more efficient than the well known Viterbi (1967) algorithm View full abstract»

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  • Exponential bounds for list size moments and error probability

    Publication Year: 1998
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (100 KB)

    We consider list decoding with a variable list size for discrete memoryless channels. We obtain simultaneous upper bounds on the error probability and the moments of list size View full abstract»

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  • Distance profile of multilevel coded transmission and rate design

    Publication Year: 1998, Page(s):10 - 11
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (216 KB)

    The analytic estimation of the error probability at the individual levels of a multilevel coding (MLC) scheme based on the distance profile in Euclidean space is given. An obvious application is to design the individual rates of an MLC scheme according to the criterion of approximately equal bit error probabilities at all levels. This so-called error probability rule is demonstrated for 16-state c... View full abstract»

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  • Generalized concatenated CPFSK modulation

    Publication Year: 1998, Page(s):102 - 103
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (220 KB)

    Using the principles of generalized concatenation we introduce a new design for encoded M-ary CPFSK systems with modulation index h=1/M. This technique is based on a set partitioning method of inner CPFSK into nested subsystems with increasing free Euclidean distance. The subsystems are combined with several outer convolutional codes having different error-correcting capabilities. We describe a mu... View full abstract»

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  • Fuzzy estimation of unknown source model for universal coding

    Publication Year: 1998, Page(s):17 - 18
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (128 KB)

    An “estimation-like” algorithm of sequential universal coding of sources with unknown model is proposed. It is shown that for the set of all context tree models, with restricted depths of contexts, the maximal individual redundancy of such coding decreases not slower than O(√((logn)/n)), n→∞, where n is the message length View full abstract»

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  • A connection between the Baum-Welch algorithm and turbo decoding

    Publication Year: 1998, Page(s):12 - 13
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (176 KB)

    It is shown that the problem of APP decoding of single and parallel concatenated codes can be recast in terms of parameter estimation for one or more nonstationary hidden Markov processes. It is then shown that simple extensions of the Baum-Welch (1966, 1968, 1970) algorithm provide solutions to these problems, including solutions that duplicate the forward-backward and turbo decoding algorithms View full abstract»

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  • A state space approach for constructing MDS rate 1/n convolutional codes

    Publication Year: 1998, Page(s):116 - 117
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (160 KB)

    In this paper we provide a state space approach for constructing convolutional codes of rate 1/n and complexity δ, whose free distance is n(δ+1), the maximal possible free distance View full abstract»

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  • Toric surfaces and codes

    Publication Year: 1998, Page(s):42 - 43
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (160 KB)

    From an integral convex polytope in R2 we give an explicit description of an error-correcting code over the finite field F q of length (q-1)2. The parameters of the code are read from the polytope. The codes are obtained from toric surfaces and the results are proved using the cohomology and intersection theory of such surfaces View full abstract»

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  • Min-max power allocation for successive decoding

    Publication Year: 1998, Page(s):56 - 57
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (152 KB)

    This paper studies resource allocation in the multi-access, fading channel, with power constraints. Given a desired bit rate vector R* , we wish to determine if it is possible to achieve it with a power budget P¯: the call admissions problem. If so, we wish to achieve it using “minimal” power: the resource allocation problem. We take a min-max fairness approach to deter... View full abstract»

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  • On covering radius and dual distance

    Publication Year: 1998, Page(s):53 - 54
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (156 KB)

    We estimate the covering radius of a code when the dual distance is known. New bounds on covering radii of linear codes are derived. Also bounds for self-complementary and even-weight codes are presented View full abstract»

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  • On the effective free distance of turbo codes

    Publication Year: 1998, Page(s):120 - 121
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (148 KB)

    An expression for the Hamming weight of the (L+1)th order output of a constituent encoder is derived. This expression enables the determination of the inputs that produce outputs of finite weight. It also facilitates the calculation of the (L+1)th order effective free distance (i.e., minimum output weight) dL+1 of the encoder. Expressions and bounds for dL+1 and in particular... View full abstract»

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