IEEE Transactions on Information Theory

Volume 18 Issue 1 • January 1972

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Displaying Results 1 - 25 of 33
  • Broadcast channels

    Publication Year: 1972, Page(s):2 - 14
    Cited by:  Papers (940)  |  Patents (99)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1752 KB)

    We introduce the problem of a single source attempting to communicate information simultaneously to several receivers. The intent is to model the situation of a broadcaster with multiple receivers or a lecturer with many listeners. Thus several different channels with a common input alphabet are specified. We shall determine the families of simultaneously achievable transmission rates for many ext... View full abstract»

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  • An algorithm for computing the capacity of arbitrary discrete memoryless channels

    Publication Year: 1972, Page(s):14 - 20
    Cited by:  Papers (314)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (808 KB)

    A systematic and iterative method of computing the capacity of arbitrary discrete memoryless channels is presented. The algorithm is very simple and involves only logarithms and exponentials in addition to elementary arithmetical operations. It has also the property of monotonic convergence to the capacity. In general, the approximation error is at least inversely proportional to the number of ite... View full abstract»

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  • Narrow-band systems and Gaussianity

    Publication Year: 1972, Page(s):20 - 27
    Cited by:  Papers (32)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (813 KB)

    The approach to Gaussianity of the output<tex>y(t)</tex>of a narrow-band system<tex>h(t)</tex>is investigated. It is assumed that the input<tex>x(t)</tex>is an<tex>a</tex>-dependent process, in the sense that the random variables<tex>x(t)</tex>and<tex>x(t + u)</tex>are independent for<tex>u &gt; a</tex>. With&l... View full abstract»

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  • Level crossings of nondifferentiable shot processes

    Publication Year: 1972, Page(s):27 - 34
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1086 KB)

    An expression for the expectation of level crossings of a class of nondifferentiable shot processes that involve impulse responses having discontinuities is derived. Its first term is essentially the Rician formula [l, pp. 51-53] except that the random variables<tex>(y_o, \dot{y}_o)</tex>in the integrand are conditioned on nonoccurrence of discontinuities and can be interpreted as yiel... View full abstract»

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  • A statistical theory of reverberation and similar first-order scattered fields--III: Waveforms and fields

    Publication Year: 1972, Page(s):35 - 67
    Cited by:  Papers (19)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (4756 KB)

    A theory of reverberation and related first-order scattered fields, developed earlier by the author, is now extended to include the often critical effects of absorption in the medium, multiple specular reflections, and nonzero velocity gradients<tex>(\nabla_c \neq 0)</tex>. As before, a combination of field and ray theory is used to obtain typical scattered and reflected waveforms; a s... View full abstract»

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  • A statistical theory of reverberation and similar first-order scattered fields--IV: Statistical models

    Publication Year: 1972, Page(s):68 - 90
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (3397 KB)

    The earlier theory (Parts I and II) is extended to include the determination of various important statistics of the reverberation process under the broadened conditions of and using the results for the scattered and reflected fields developed in Part III. The new conditions involve nonzero velocity gradients, absorbing media, and multiple reflections, as well as the usual Doppler, general signals ... View full abstract»

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  • Filtering and detection for doubly stochastic Poisson processes

    Publication Year: 1972, Page(s):91 - 102
    Cited by:  Papers (115)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1625 KB)

    Equations are derived that describe the time evolution of the posterior statistics of a general Markov process that modulates the intensity function of an observed inhomogeneous Poisson counting process. The basic equation is a stochastic differential equation for the conditional characteristic function of the Markov process. A separation theorem is established for the detection of a Poisson proce... View full abstract»

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  • Asymptotic properties of Bayes estimates of parameters of a signal masked by interference

    Publication Year: 1972, Page(s):102 - 106
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (712 KB)

    It is shown that for a class of cost functions and a class of a priori distributions on the parameters to be estimated, the risks associated with the Bayes and maximum-likelihood estimates of the signal parameters become equal as the number of observations becomes large. This implies that the optimality properties usually attributed to Bayes estimates can be attributed in some cases to maximum-lik... View full abstract»

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  • Coupled detection- estimation of Gaussian processes in Gaussian noise

    Publication Year: 1972, Page(s):106 - 110
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (712 KB)

    This paper considers the joint detection and estimation of Gauss-Markov processes in white Gaussian noise, where the operations of detection and estimation are strongly coupled. Explicit Bayes' optimal recursive estimation and detection rules are derived, and it is shown that the resulting optimal receiver is amenable to a causal estimator-correlator-type interpretation. View full abstract»

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  • Nonparametric detection using spectral data

    Publication Year: 1972, Page(s):110 - 118
    Cited by:  Papers (17)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1418 KB)

    A detection system is considered that analyzes the spectrum of the time-series output from a sensing element. The spectral data consist of a matrix of estimates of the energy in many small time-frequency cells. A decision procedure is formulated that is based on the multiple use of a two-sample statistic operating on the columns of the matrix. If the input noise is Gaussian with unknown power, the... View full abstract»

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  • Small-sample optimality of design techniques for linear classifiers of Gaussian patterns

    Publication Year: 1972, Page(s):118 - 126
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1262 KB)

    Adaptive algorithms for designing two-category linear pattern classifiers have been widely used on nonseparable pattern sets even though they do not directly minimize the number of classification errors and their optimality for pattern classification is not completely known. Many of these algorithms have been shown to be asymptotically optimal for patterns from Gaussian distributions with equal-co... View full abstract»

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  • Parameter identification using intrinsic dimensionality

    Publication Year: 1972, Page(s):126 - 133
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (976 KB)

    Let<tex>W</tex>be an<tex>N</tex>-dimensional vector space and<tex>V</tex>be a<tex>K</tex>- dimensional topological hypersurface in<tex>W</tex>. The intrinsic dimensionality problem can be stated as follows. Given<tex>M</tex>randomly selected points<tex>\nu_i, \nu_i \in V</tex>, estimate<tex>K</tex>, whi... View full abstract»

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  • A critical statistic for channels with memory

    Publication Year: 1972, Page(s):133 - 141
    Cited by:  Papers (32)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1131 KB)

    We present a new descriptive statistic for channels with memory and show its utility a) in evaluating and comparing existing models for such channels and b) as a theoretical tool in defining the error-gap distribution characteristics of real channels. We demonstrate that certain kinds of real channel behavior cannot be adequately described by previously proposed models and offer an example of a be... View full abstract»

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  • Communication over fading dispersive channels with feedback

    Publication Year: 1972, Page(s):142 - 150
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1207 KB)

    An intermittent on-off noiseless feedback scheme for binary communication over the slow- and fast-fading Rayleigh channels is proposed and analyzed. At high energy-to-noise ratios, doubling the number of feedback iterations yields a 3-dB power saving for the slowly fading channel. Power savings ranging from 1 dB for one feedback iteration to 9 dB for 16 iterations are typical for the fast-fading m... View full abstract»

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  • A bound on the rate-distortion function and application to images

    Publication Year: 1972, Page(s):150 - 159
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1500 KB)

    An upper bound on the rate-distortion function for discrete ergodic sources with memory is developed by partitioning the source sample space into a finite number of disjoint subsets and bounding the rates for each subset. The bound depends only on the mean vectors and covariance matrices for the subsets and is easy to compute. It is tighter than the Gaussian bound for sources that exhibit clusteri... View full abstract»

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  • Permutation codes for sources

    Publication Year: 1972, Page(s):160 - 169
    Cited by:  Papers (71)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1580 KB)

    Source encoding techniques based on permutation codes are investigated. For a broad class of distortion measures it is shown that optimum encoding of a source permutation code is easy to instrument even for very long block lengths. Also, the nonparametric nature of permutation encoding is well suited to situations involving unknown source statistics. For the squared-error distortion measure a proc... View full abstract»

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  • Class of algorithms for decoding block codes with channel measurement information

    Publication Year: 1972, Page(s):170 - 182
    Cited by:  Papers (631)  |  Patents (98)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (2016 KB)

    A class of decoding algorithms that utilizes channel measurement information, in addition to the conventional use of the algebraic properties of the code, is presented. The maximum number of errors that can, with high probability, be corrected is equal to one less than<tex>d</tex>, the minimum Hamming distance of the code. This two-fold increase over the error-correcting capability of ... View full abstract»

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  • Random error and burst correction by iterated codes

    Publication Year: 1972, Page(s):182 - 185
    Cited by:  Papers (36)  |  Patents (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (640 KB)

    We give a decoding algorithm for iterated codes that can correct up to the number of errors guaranteed by the product minimum distance, rather than about half that number when the iterated codes are decoded independently. This result is achieved by adapting Forney's generalized minimum distance decoding for use with iterated codes. We derive results on the simultaneous burst- and random-error-corr... View full abstract»

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  • Hybrid block- self-orthogonal convolutional codes

    Publication Year: 1972, Page(s):185 - 191
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1057 KB)

    Two convolutional-code construction schemes that utilize block codes are given. In the first method the generators of a self-orthogonal convolutional code (SOCC) are expanded. The generators of a block code whose block length is longer than that of the SOCC code replace the nonzero blocks of the convolutional code. The zero blocks are extended to the longer block length. There results a convolutio... View full abstract»

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  • On the structure of rate<tex>1/n</tex>convolutional codes

    Publication Year: 1972, Page(s):192 - 196
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (767 KB)

    We show what choice there is in assigning output digits to transitions of a binary rate<tex>1/n</tex>code trellis so that the latter will correspond to a convolutional code. We then prove that in any rate<tex>\frac{1}{2}</tex>noncatastrophic code of constraint length<tex>\upsilon</tex>each binary sequence of length<tex>2j</tex><tex>(1 \leq j \l... View full abstract»

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  • Variable-length codes and the Fano metric

    Publication Year: 1972, Page(s):196 - 198
    Cited by:  Papers (86)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (424 KB)

    It is shown that the metric proposed originally by Fano for sequential decoding is precisely the required statistic for minimum-error-probability decoding of variable-length codes. The analysis shows further that the "natural" choice of bias in the metric is the code rate and gives insight into why the Fano metric has proved to be the best practical choice in sequential decoding. The recently devi... View full abstract»

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  • On the error probability of sequential decoding on the BSC

    Publication Year: 1972, Page(s):199 - 202
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (520 KB)

    Upper bounds are derived on the error probability that can be achieved by using the maximum-likelihood algorithm of sequential decoding for the binary symmetric channel. The bounds are functions of constraint length and backsearch limit. View full abstract»

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  • Weight distributions of the cosets of the (32,6) Reed-Muller code

    Publication Year: 1972, Page(s):203 - 207
    Cited by:  Papers (65)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (678 KB)

    In this paper we present the weight distribution of all<tex>2^26</tex>cosets of the (32,6) first-order Reed-Muller code. The code is invariant under the complete affine group, of order<tex>32 \times 31 \times 30 \times 28 \times 24 \times</tex>16. In the Appendix we show (by hand computations) that this group partitions the<tex>2^26</tex>cosets into only 48 equi... View full abstract»

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  • Photon counting and Laguerre detection (Corresp.)

    Publication Year: 1972, Page(s):208 - 211
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (664 KB)

    In this correspondence maximum-likelihood binary detection theory is applied to an incoherent optical system model employing photodetectors governed by Laguerre counting statistics. It is shown that a maximum-likelihood Laguerre detector corresponds to a count comparison over each signaling interval. Laguerre error probabilities are presented and compared with those for Poisson counting. View full abstract»

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  • Finite-time-averaged power spectra and signal energy distribution in time and frequency (Corresp.)

    Publication Year: 1972, Page(s): 208
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (158 KB)

    In response to a recent paper, this correspondence points out the difficulty of applying the concept of the energy distribution in time and frequency of deterministic signals to random signals and finite-time-averaged power spectra. For deterministic signals, an appropriately defined finite-time spectrum will indicate the frequency band within which the signal energy is concentrated at a particula... 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