IEEE Transactions on Information Theory

Volume 14 Issue 3 • May 1968

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Displaying Results 1 - 25 of 30
  • Estimates of<tex>epsilon</tex>capacity for certain linear communication channels

    Publication Year: 1968, Page(s):361 - 369
    Cited by:  Papers (16)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1507 KB)

    The following simple abstract model for a class of communications problems is adopted: the set of possible transmitted signals<tex>x</tex>is taken to be the unit ball in the<tex>L_{2}</tex>space of functions defined on<tex>[-T, T]</tex>(bounded energy); the transmitted signal is assumed to be operated on by a convolution operator<tex>H</tex>; and the... View full abstract»

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  • Signal energy distribution in time and frequency

    Publication Year: 1968, Page(s):369 - 374
    Cited by:  Papers (224)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1002 KB)

    The Fourier representation of signals and its relation to the signal structure in time and frequency, and more generally the inherent properties of phase-modulated signals, have received considerable attention in the past. These topics have led to such seemingly unrelated studies as the representation of a signal in a combined time-frequency plane, "instantaneous power spectra," and the ambiguity ... View full abstract»

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  • A generalized concept of frequency and some applications

    Publication Year: 1968, Page(s):375 - 382
    Cited by:  Papers (39)  |  Patents (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1313 KB)

    The system of sine and cosine functions has been distinguished historically in communications. Whenever the term frequency is used, reference is made implicitly to these functions; hence the generally used theory of communication is based on the system of sine and cosine functions. In recent years other complete systems of orthogonal functions have been used for theoretical investigations as well ... View full abstract»

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  • The clipping loss in correlation detectors for arbitrary input signal-to-noise ratios

    Publication Year: 1968, Page(s):382 - 389
    Cited by:  Papers (16)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (914 KB)

    The detection of stationary Gaussian signals in a background of stationary Gaussian noise by the analog multiplier correlator, the polarity coincidence correlator (PCC), and the sample polarity coincidence correlator (SPCC) is considered. It is assumed that signal and noise have identical normalized autocovariance functions, and they are not cross correlated with each other. The main contributions... View full abstract»

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  • Data compression using straight line interpolation

    Publication Year: 1968, Page(s):390 - 394
    Cited by:  Papers (23)  |  Patents (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (700 KB)

    One simple method of data compression relies on the approximation of the source output by polynomial segments or "interpolators." The parameters of each polynomial are transmitted in place of the original data. This paper presents a method of theoretically analyzing such techniques. Straight line interpolation is considered specifically although the ideas can he readily generalized. It is shown th... View full abstract»

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  • Estimation of linear weighting functions in Gaussian noise

    Publication Year: 1968, Page(s):395 - 407
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1967 KB)

    The measurement of linear time-varying systems and the mapping of densely distributed radar targets provide the motivation for the problem of estimation of linear multidimensional weighting functions in Gaussian noise. The assumption that the weighting function to be estimated is a sample of a Gaussian process of known autocorrelation function, and the adoption of either a maximum a posteriori pro... View full abstract»

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  • On a class of unsupervised estimation problems

    Publication Year: 1968, Page(s):407 - 415
    Cited by:  Papers (17)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1452 KB)

    The unsupervised estimation problem has received considerable attention during the last three years. The problem usually considered, however, is only one of a class of unsupervised estimation problems. In this paper, a "mixture approach" defined previously is used to define this class of unsupervised estimation problems, and state precisely the a priori knowledge used to define each problem. After... View full abstract»

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  • The theory of amorphous cloud trajectory prediction

    Publication Year: 1968, Page(s):415 - 427
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1801 KB)

    Techniques are discussed for using cloud maps (observations) made on a moving cloud of particles to predict the cloud's future location and shape. The amorphous cloud concept is used to model particle clouds in terms of surfaces moving through state space. Observations are modeled by possibly 'noisy' surfaces obtained by projecting the state space cloud onto the observation space. Deterministic an... View full abstract»

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  • A television scanning scheme for a detector-noise-limited system

    Publication Year: 1968, Page(s):428 - 433
    Cited by:  Papers (23)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (887 KB)

    The signal-to-noise ratio at a single-element detector scanning a television picture can be improved if the detector receives light from many picture elements simultaneously. This paper describes a scanning reticle, with transparent and opaque elements chosen according to a binary biorthogonal sequence, that will provide an exact reproduction in the same scanning time as a reticle scanning only on... View full abstract»

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  • Simultaneous optimum detection and estimation of signals in noise

    Publication Year: 1968, Page(s):434 - 444
    Cited by:  Papers (129)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1767 KB)

    The problem of simultaneous detection and estimation of signals in noise is formulated in the language of statistical decision theory. Optimum structures and corresponding general measures of system performance are derived under the Bayes criterion of minimum average risk for the detectors and estimators appropriate to this type of joint operation: It is shown that whereas the structures of the re... View full abstract»

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  • A recursive approach to signal detection

    Publication Year: 1968, Page(s):445 - 450
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (801 KB)

    The classical problem of detecting known signals in additive nonstationary nonwhite noise is treated using state-variable methods. The noise is assumed to be generated as the solution of a linear time-varying differential equation driven by white noise. The Markov property of the noise is used to derive a difference equation for the likelihood ratio. The terms in the difference equation are given ... View full abstract»

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  • An optimum decision-directed scheme for Gaussian mixtures

    Publication Year: 1968, Page(s):451 - 461
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1616 KB)

    The problem of making measurements upon some available signal mixture in order to extract or estimate certain parametric data for subsequent signal detection using the measurement data is considered. The development is carried out for a formal binary signal observation mixture (no a priori classification of the observations into isolated category or class ensembles is assumed), with the parameters... View full abstract»

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  • Approximating discrete probability distributions with dependence trees

    Publication Year: 1968, Page(s):462 - 467
    Cited by:  Papers (847)  |  Patents (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (893 KB)

    A method is presented to approximate optimally an<tex>n</tex>-dimensional discrete probability distribution by a product of second-order distributions, or the distribution of the first-order tree dependence. The problem is to find an optimum set of<tex>n - 1</tex>first order dependence relationship among the<tex>n</tex>variables. It is shown that the procedure d... View full abstract»

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  • Optimal unsupervised learning multicategory dependent hypotheses pattern recognition

    Publication Year: 1968, Page(s):468 - 470
    Cited by:  Papers (17)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (480 KB)

    A Bayesian decision theory approach is applied to the solution of the problem of unsupervised parametric pattern recognition. The parametric model for this investigation includes the cases where both constant and time-varying unknown parameters are present, and, most significantly, the unknown hypotheses do not constitute a statistically independent sequence. They are restricted only to be from a ... View full abstract»

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  • Feedback coding schemes for an additive noise channel with a noisy feedback link

    Publication Year: 1968, Page(s):471 - 480
    Cited by:  Papers (19)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1322 KB)

    A coding scheme for an additive Gaussian channel is developed using a noisy feedback link and<tex>D</tex>-dimensional elementary signals with no bandwidth constraint. This allows error-free transmission at a rate<tex>R &lt; R_{c}</tex>where<tex>R_{c}</tex>is slightly less than the channel capacity<tex>C</tex>. When there is no noise in the feedba... View full abstract»

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  • A geometric treatment of the source encoding of a Gaussian random variable

    Publication Year: 1968, Page(s):481 - 486
    Cited by:  Papers (68)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (909 KB)

    This paper gives a geometric treatment of the source encoding of a Gaussian random variable for minimum mean-square error. The first section is expository, giving a geometric derivation of Shannon's classic result [1] which explicitly shows the steps in source encoding and the properties that a near optimum code must possess. The second section makes use of the geometric insight gained in the firs... View full abstract»

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  • A weight distribution bound for linear codes

    Publication Year: 1968, Page(s):487 - 490
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (565 KB)

    A linear code of block length n possessing minimum weight d has one code word of weight zero, and no other code words of weight less than<tex>d</tex>. The weight distribution of the code is given by the set of all<tex>W(j), d \leq j \leq n</tex>, describing the number of code words having a weight of exactly<tex>j</tex>. Exact weight distributions are known for ... View full abstract»

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  • Buffer overflow in variable length coding of fixed rate sources

    Publication Year: 1968, Page(s):490 - 501
    Cited by:  Papers (64)  |  Patents (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1791 KB)

    In this paper, we develop and analyze an easily instrumentable scheme for variable length encoding of discrete memoryless fixed-rate sources in which buffer overflows result in codeword erasures at locations that are perfectly specified to the user. Thus, no loss of synchronism ever occurs. We find optimal (i.e., minimizing the probability of buffer overflow) code-wold length requirements under th... View full abstract»

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  • Evaluation of expurgated bound exponents

    Publication Year: 1968, Page(s):501 - 505
    Cited by:  Papers (24)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (631 KB)

    In this paper, we investigate the problem of optimizing the expurgated upper bound to the probability of error associated with transmission over discrete memoryless channels. We find a general sufficient condition under which, for a given value of the parameter<tex>\varrho \varepsilon [1, \infty)</tex>, the channel input distribution that leads to the optimal exponent corresponds to a ... View full abstract»

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  • The rate distortion function of a Gaussian process with a weighted square error criterion (Corresp.)

    Publication Year: 1968, Page(s):506 - 508
    Cited by:  Papers (26)
    Request permission for commercial reuse | PDF file iconPDF (471 KB)
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  • Interpretation of the expression for the information y gives about X (Corresp.)

    Publication Year: 1968, Page(s):508 - 509
    Request permission for commercial reuse | PDF file iconPDF (293 KB)
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  • On the lower bound of zero-error capacity (Corresp.)

    Publication Year: 1968, Page(s):509 - 510
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (267 KB)

    It is shown that the lower bound on zero-error capacity<tex>C_{0}</tex>as presented by Shannon [1] and Gallager [2] is<tex>\ln \alpha</tex>, where<tex>\alpha</tex>is the maximum number of channel input symbols, no two of which have a common output symbol. View full abstract»

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  • A note on the autocorrelation function of FM by a sine wave plus noise (Corresp.)

    Publication Year: 1968, Page(s):510 - 512
    Request permission for commercial reuse | PDF file iconPDF (286 KB)
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  • On the generation of all spectral factors (Corresp.)

    Publication Year: 1968, Page(s):512 - 514
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (452 KB)

    Two solutions are presented to the problem of finding from one spectral factorization all spectral factorizations of a non-negative para-Hermitian matrix. The first solution results from the theory of equivalent networks while the second is given through a derivation from first principles. View full abstract»

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  • Recursive computations for the optimal tracking of time-varying parameters (Corresp.)

    Publication Year: 1968, Page(s):514 - 515
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (343 KB)

    Recursive relations are given for updating the conditional density<tex>p(\theta_{k} | X_{k-1}, \cdots X_{1})</tex>(also for<tex>p(\theta_{k} | X_{k}, \cdots, X_{1})</tex>), where<tex>\theta_{k}</tex>is a parameter of the density of<tex>X_{k}</tex>. The observations<tex>X_{1}, X_{2}, \cdots</tex>are assumed to be conditionally independent ... 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