IEEE Transactions on Information Theory

Volume 46 Issue 7 • Nov. 2000

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Displaying Results 1 - 25 of 54
  • Fundamental limits for information retrieval

    Publication Year: 2000, Page(s):2281 - 2298
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (386 KB)

    The fundamental limits of performance for a general model of information retrieval from databases are studied. In the scenarios considered, a large quantity of information is to be stored on some physical storage device. Requests for information are modeled as a randomly generated sequence with a known distribution. The requests are assumed to be "context-dependent," i.e., to vary according to the... View full abstract»

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  • On the capacity and error-correcting codes of write-efficient memories

    Publication Year: 2000, Page(s):2299 - 2314
    Cited by:  Papers (18)  |  Patents (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (492 KB)

    Write-efficient memories (WEMs) were introduced by Ahlswede and Zhang (1989) as a model for storing and updating information on a rewritable medium with cost constraints. We note that the research work of Justesen and Hoholdt (1984) on maxentropic Markov chains actually provide a method for calculating the capacity of WEM. By using this method, we derive a formula for the capacity of WEM with a do... View full abstract»

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  • Mismatched decoding revisited: general alphabets, channels with memory, and the wide-band limit

    Publication Year: 2000, Page(s):2315 - 2328
    Cited by:  Papers (109)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (425 KB)

    The mismatch capacity of a channel is the highest rate at which reliable communication is possible over the channel with a given (possibly suboptimal) decoding rule. This quantity has been studied extensively for single-letter decoding rules over discrete memoryless channels (DMCs). Here we extend the study to memoryless channels with general alphabets and to channels with memory with possibly non... View full abstract»

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  • Coding for tolerance and detection of skew in parallel asynchronous communications

    Publication Year: 2000, Page(s):2329 - 2335
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (205 KB)

    We provide a new definition for the concept of skew in parallel asynchronous communications introduced by Blaum and Bruck (1993). The new definition extends and strengthens previously known results on skew. We give necessary and sufficient conditions for codes that can tolerate a certain amount of skew under the new definition. We also extend the results to codes that can tolerate a certain amount... View full abstract»

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  • Permutation fixed points with application to estimation of minimum distance of turbo codes

    Publication Year: 2000, Page(s):2336 - 2349
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (286 KB)

    We present a systematic technique for obtaining all the input sequences that are mapped by a given permutation either to themselves or to shifted versions of themselves (generically called permutation fixed points). Such sequences or their subsets, represent the primary candidates for examination in connection with obtaining estimates of the minimum distance of parallel concatenated codes, special... View full abstract»

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  • A transform approach to permutation groups of cyclic codes over Galois rings

    Publication Year: 2000, Page(s):2350 - 2358
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (334 KB)

    Berger and Charpin (see ibid., vol.42, p.2194-2209, 1996 and Des., Codes Cuyptogr., vol.18, no.1/3, p.29-53, 1999) devised a theoretical method of calculating the permutation group of a primitive cyclic code over a finite field using permutation polynomials and a transform description of such codes. We extend this method to cyclic and extended cyclic codes over the Galois ring GR (p/sup a/, m), de... View full abstract»

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  • On covering radii and coset weight distributions of extremal binary self-dual codes of length 56

    Publication Year: 2000, Page(s):2359 - 2372
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (516 KB)

    We present a method to determine the complete coset weight distributions of doubly even binary self-dual extremal [56, 28, 12] codes. The most important steps are (1) to describe the shape of the basis for the linear space of rigid Jacobi polynomials associated with such codes in each index i, (2) to describe the basis polynomials for the coset weight enumerators of the assigned coset weight i by ... View full abstract»

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  • Upper bounds for constant-weight codes

    Publication Year: 2000, Page(s):2373 - 2395
    Cited by:  Papers (76)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (763 KB)

    Let A(n,d,w) denote the maximum possible number of codewords in an (n,d,w) constant-weight binary code. We improve upon the best known upper bounds on A(n,d,w) in numerous instances for n/spl les/24 and d/spl les/12, which is the parameter range of existing tables. Most improvements occur for d=8, 10, where we reduce the upper bounds in more than half of the unresolved cases. We also extend the ex... View full abstract»

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  • Optical orthogonal codes: their bounds and new optimal constructions

    Publication Year: 2000, Page(s):2396 - 2406
    Cited by:  Papers (112)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (348 KB)

    A (v, k, /spl lambda//sub a/, /spl lambda//sub c/) optical orthogonal code (OOC) C is a family of (0, 1)-sequences of length v and weight k satisfying the following two correlation properties: (1) /spl Sigma//sub 0/spl les/t/spl les/v-1/x/sub t/x/sub t+i//spl les//spl lambda//sub a/ for any x=(x/sub 0/,x/sub 1/,/spl middot//spl middot//spl middot/,x/sub v-1/)/spl isin/C and any integer i not equiv... View full abstract»

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  • On identification capacity of infinite alphabets or continuous-time channels

    Publication Year: 2000, Page(s):2407 - 2414
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (252 KB)

    Two kinds of channels are considered: (1) discrete-time channel with additive noise, and (2) Poisson and white Gaussian (i.e., continuous-time) channels. For the type (1) channel there are given some sufficient conditions when the Shannon and identification capacities coincide. It is shown that the identification capacity of Poisson and Gaussian channels without bandwidth constraint is infinite. C... View full abstract»

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  • Hypothesis testing with the general source

    Publication Year: 2000, Page(s):2415 - 2427
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (466 KB)

    The asymptotically optimal hypothesis testing problem, with general sources as the null and alternative hypotheses, is studied under exponential-type error constraints on the first kind of error probability. Our fundamental philosophy is to convert all of the hypothesis testing problems to the pertinent computation problems in the large deviation-probability theory. This methodologically new appro... View full abstract»

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  • Strong converse and Stein's lemma in quantum hypothesis testing

    Publication Year: 2000, Page(s):2428 - 2433
    Cited by:  Papers (111)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (192 KB)

    The hypothesis testing problem for two quantum states is treated. We show a new inequality between the errors of the first kind and the second kind, which complements the result of Hiai and Petz (1991) to establish the quantum version of Stein's lemma. The inequality is also used to show a bound on the probability of errors of the first kind when the power exponent for the probability of errors of... View full abstract»

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  • Asymptotic average redundancy of Huffman (and other) block codes

    Publication Year: 2000, Page(s):2434 - 2443
    Cited by:  Papers (40)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (308 KB)

    We study asymptotically the redundancy of Huffman (and other) codes. It has been known from the inception of the Huffman (1952) code that in the worst case its redundancy-defined as the excess of the code length over the optimal (ideal) code length-is not more than one. However, to the best of our knowledge no precise asymptotic results have been reported in literature thus far. We consider here a... View full abstract»

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  • Asymptotically optimal low-complexity sequential lossless coding for piecewise-stationary memoryless sources .I. The regular case

    Publication Year: 2000, Page(s):2444 - 2467
    Cited by:  Papers (21)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (623 KB)

    The lower bound on the redundancy for lossless universal coding of regular memoryless sources with a bounded number of abrupt changes in the statistics is shown to be asymptotically achievable using a fixed per-letter computational complexity sequential compression scheme with fixed storage complexity. The scheme which outperforms any other known fixed-complexity scheme when regularity conditions ... View full abstract»

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  • Performance of quantizers on noisy channels using structured families of codes

    Publication Year: 2000, Page(s):2468 - 2476
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (215 KB)

    Achievable distortion bounds are derived for the cascade of structured families of binary linear channel codes and binary lattice vector quantizers. It is known that for the cascade of asymptotically good channel codes and asymptotically good vector quantizers the end-to-end distortion decays to zero exponentially fast as a function of the overall transmission rate, and is achieved by choosing a c... View full abstract»

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  • Optimal subband filter banks for multiple description coding

    Publication Year: 2000, Page(s):2477 - 2490
    Cited by:  Papers (37)  |  Patents (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (354 KB)

    Multiple description coding refers to the encoding of an information source into multiple bit streams, in a manner that each bit stream independently represents a "coarse" description of the source, while multiple descriptions jointly convey a higher fidelity source representation. Thus multiple description coding allows enhanced resilience to loss of individual descriptions, and can be viewed as ... View full abstract»

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  • The analysis and design of windowed Fourier frame based multiple description source coding schemes

    Publication Year: 2000, Page(s):2491 - 2536
    Cited by:  Papers (17)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1549 KB)

    In this paper the windowed Fourier encoding-decoding scheme applied to the multiple description compression problem is analyzed. In the general case, four window functions are needed to define the encoder and decoder, although this number can be reduced to three or two by using time-shift or frequency-shift division schemes. The encoding coefficients are next divided into two groups according to t... View full abstract»

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  • MDL denoising

    Publication Year: 2000, Page(s):2537 - 2543
    Cited by:  Papers (97)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (165 KB)

    'The so-called denoising problem, relative to normal models for noise, is formalized such that "noise" is defined as the incompressible part in the data while the compressible part defines the meaningful information-bearing signal. Such a decomposition is effected by minimization of the ideal code length, called for by the minimum description length (MDL) principle, and obtained by an application ... View full abstract»

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  • Bounds for the MSE performance of constant modulus estimators

    Publication Year: 2000, Page(s):2544 - 2560
    Cited by:  Papers (26)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (481 KB)

    The constant modulus (CM) criterion has become popular in the design of blind linear estimators of sub-Gaussian independent and identically distributed (i.i.d.) processes transmitted through unknown linear channels in the presence of unknown additive interference. In this paper, we present an upper bound for the conditionally unbiased mean-squared error (UMSE) of CM-minimizing estimators that depe... View full abstract»

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  • The Kalman filter as the optimal linear minimum mean-squared error multiuser CDMA detector

    Publication Year: 2000, Page(s):2561 - 2566
    Cited by:  Papers (25)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (180 KB)

    It is shown that a first-order linear state-space model applies to the asynchronous code-division multiple-access (CDMA) channel, and thus the Kalman filter produces symbol estimates with the minimum mean-squared error (MMSE) among all linear filters, in long- or short-code systems for a given detection delay. This result may be used as a benchmark against which to compare the performance of other... View full abstract»

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  • Differential space-time modulation

    Publication Year: 2000, Page(s):2567 - 2578
    Cited by:  Papers (673)  |  Patents (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (353 KB)

    Space-time coding and modulation exploit the presence of multiple transmit antennas to improve the performance on multipath radio channels. Thus far, most work on space-time coding has assumed that perfect channel estimates are available at the receiver. In certain situations, however, it may be difficult or costly to estimate the channel accurately, in which case it is natural to consider the des... View full abstract»

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  • On the achievable information rate with peak-power-limited orthogonal frequency-division multiplexing

    Publication Year: 2000, Page(s):2579 - 2587
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (207 KB)

    This paper addresses the problem of determining the statistical distribution of the peak-to-average power ratio (PAR) of orthogonal frequency-division multiplexing (OFDM) transmit signals. In practice, transmission systems are amplitude-limited, thus the large peak values of OFDM signals are clipped and nonlinear distortion follows. In order to avoid the resulting degradations, i.e., spectral wide... View full abstract»

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  • The ballot theorem strikes again: packet loss process distribution

    Publication Year: 2000, Page(s):2588 - 2595
    Cited by:  Papers (20)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (182 KB)

    The probability distribution of the number of lost packets within a block of consecutive packet arrivals into a finite buffer is an important quantity in various networking problems. In a previous paper, Cidon, Khamisy and Sidi (1993) introduced a recursive scheme to derive this distribution. In this paper, we derive explicit expressions for this distribution using various versions of the powerful... View full abstract»

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  • Secret sharing schemes with bipartite access structure

    Publication Year: 2000, Page(s):2596 - 2604
    Cited by:  Papers (40)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (315 KB)

    We study the information rate of secret sharing schemes whose access structure is bipartite. In a bipartite access structure there are two classes of participants and all participants in the same class play an equivalent role in the structure. We characterize completely the bipartite access structures that can be realized by an ideal secret sharing scheme. Both upper and lower bounds on the optima... View full abstract»

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  • A Hensel lifting to replace factorization in list-decoding of algebraic-geometric and Reed-Solomon codes

    Publication Year: 2000, Page(s):2605 - 2614
    Cited by:  Papers (12)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (417 KB)

    This article presents an algorithmic improvement to Sudan's (see J. Complexity, vol.13, p.180-93, 1997) list-decoding algorithm for Reed-Solomon codes and its generalization to algebraic-geometric codes from Shokrollahi and Wasserman (see ibid., vol.45, p.432-37, 1999). Instead of completely factoring the interpolation polynomial over the function field of the curve, we compute sufficiently many c... 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