IEEE Transactions on Information Theory

Issue 5 • Sep 1989

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Displaying Results 1 - 25 of 29
  • Estimates of performance sensitivity of a stochastic system

    Publication Year: 1989, Page(s):1058 - 1068
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (652 KB)

    Three kinds of estimates of the performance sensitivity of a stochastic system are discussed. The convergence properties of these estimates are investigated. The first estimate, using the time average of the derivative of the performance function calculated along a sample trajectory, is generally preferable when certain conditions hold for the performance function. The variance of the second estim... View full abstract»

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  • A simple window random access algorithm with advantageous properties

    Publication Year: 1989, Page(s):1124 - 1130
    Cited by:  Papers (72)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (560 KB)

    A simple full-feedback-sensing window random access algorithm is proposed and analyzed. The throughput of the algorithm is 0.429; its delay and resistance to feedback channel errors are better than those induced by J.I. Capetanakis's (ibid., vol.IT-25, p.505-15, Sept. 1979) window algorithm. In addition, the simple operations of the algorithm allow for the analytical evaluation of the output-traff... View full abstract»

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  • On the nonexistence of Barker arrays and related matters

    Publication Year: 1989, Page(s):1048 - 1057
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (724 KB)

    Evidence is presented to support the conclusion that there exists only one equivalence class of binary two-dimensional arrays (both dimensions greater than 1) of +1's and -1's with all out-of-phase aperiodic autocorrelation values bounded in magnitude by unity. It is proved that no such array exists when either dimension is an odd prime or when one dimension is an odd integer and the other is twic... View full abstract»

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  • Holographic dispersal and recovery of information

    Publication Year: 1989, Page(s):1123 - 1124
    Cited by:  Papers (24)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (212 KB)

    A simple scheme for dispersal and recovery of digital information based on the discrete Fourier transform is discussed. The author presents a different implementation of M.O. Rabin's (J. ACM, vol.36, no.2, p.335-48, Apr. 1989) scheme, whose recovery cost is O(log m+k) operations per character, assuming m=Θ(n); for example, when k=Θ(... View full abstract»

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  • Connectivity properties of a packet radio network model

    Publication Year: 1989, Page(s):1044 - 1047
    Cited by:  Papers (148)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (296 KB)

    A model of a packet radio network in which transmitters with range R are distributed according to a two-dimensional Poisson point process with density D is examined. To ensure network connectivity, it is shown that πR2D, the expected number of nearest neighbors of a transmitter, must grow logarithmically with the area of the network. For an infinit... View full abstract»

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  • Hamming distance preserving mappings and trellis codes with constrained binary symbols

    Publication Year: 1989, Page(s):1098 - 1103
    Cited by:  Papers (23)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (532 KB)

    The transformation of a linear convolutional code into a run-length-constrained or balanced trellis code with the same or larger free distance is investigated. The transformation involves a Hamming-distance-preserving mapping of the set of unconstrained binary symbols of the convolutional code onto a set of suitably constrained symbols. Simple tests to determine if these mappings can exist and a t... View full abstract»

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  • Quantum communication with coherent states

    Publication Year: 1989, Page(s):1114 - 1123
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (768 KB)

    Quantum communication is studied under the cutoff-rate criterion for transmission of M coherent states of real amplitude (M =2, . . ., 7). Comparison with other measurement operators of interest, such as the number and the quasi-classical operators, is made. The effect of quantization of the decision level on the cutoff rate is considered View full abstract»

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  • Splitting algorithms in noisy channels with memory

    Publication Year: 1989, Page(s):1034 - 1043
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (788 KB)

    Multi-access networks are considered in which the shared channel is noisy. The authors assume a slotted-time collision-type channel, Poisson infinite-user model, and binary feedback. Due to the noise in the shared channel, the received signal may be detected as a collision even though no message or a single message is transmitted. This kind of imperfect feedback is referred to as error. A common a... View full abstract»

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  • Error detection in a class of decimal codes

    Publication Year: 1989, Page(s):1095 - 1098
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (384 KB)

    Consideration is given to the problem of multiple parity checks for an n-digit number. Each check relates to specific digits, where the probability p of a particular digit being in error is fixed. The author proves that it is best, in the sense of minimizing the probability of an undetected error, to add either one or n parity checks, depending on the value of n... View full abstract»

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  • Limited search trellis decoding of convolutional codes

    Publication Year: 1989, Page(s):944 - 955
    Cited by:  Papers (87)  |  Patents (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (912 KB)

    The least storage and node computation required by a breadth-first tree or trellis decoder that corrects t errors over the binary symmetric channels is calculated. Breadth-first decoders work with code paths of the same length, without backtracking. The Viterbi algorithm is an exhaustive trellis decoder of this type; other schemes look at a subset of the tree or trellis paths. For random ... View full abstract»

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  • On Gaussian feedback capacity

    Publication Year: 1989, Page(s):1072 - 1076
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (380 KB)

    M. Pinsker and P. Ebert (Bell Syst. Tech. J., p.1705-1712, Oct.1970) proved that in channels with additive Gaussian noise, feedback at most doubles the capacity. Recently, T. Cover and S. Pombra (ibid., vol.35, no.1, p.37-43, Jan.1989) proved that feedback at most adds half a bit per transmission. Following their approach, the author proves that in the limit as signal power approaches either zero ... View full abstract»

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  • The estimation of the model order in exponential families

    Publication Year: 1989, Page(s):1109 - 1114
    Cited by:  Papers (32)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (456 KB)

    Estimators are sought that achieve high exponential rate of decrease in the underestimation probability while keeping the overestimation probability exponent at a certain prescribed level. It is assumed that a given integer is known to upper-bound the true order. Some examples are given of possible applications of the proposed method in specific order estimation and hypothesis testing problems View full abstract»

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  • Maximum likelihood soft decoding of binary block codes and decoders for the Golay codes

    Publication Year: 1989, Page(s):963 - 975
    Cited by:  Papers (78)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1096 KB)

    Maximum-likelihood soft-decision decoding of linear block codes is addressed. A binary multiple-check generalization of the Wagner rule is presented, and two methods for its implementation, one of which resembles the suboptimal Forney-Chase algorithms, are described. Besides efficient soft decoding of small codes, the generalized rule enables utilization of subspaces of a wide variety, thereby yie... View full abstract»

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  • High-resolution quantization theory and the vector quantizer advantage

    Publication Year: 1989, Page(s):1020 - 1033
    Cited by:  Papers (114)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1072 KB)

    The authors consider how much performance advantage a fixed-dimensional vector quantizer can gain over a scalar quantizer. They collect several results from high-resolution or asymptotic (in rate) quantization theory and use them to identify source and system characteristics that contribute to the vector quantizer advantage. One well-known advantage is due to improvement in the space-filling prope... View full abstract»

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  • On error-correcting balanced codes

    Publication Year: 1989, Page(s):1091 - 1095
    Cited by:  Papers (23)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (456 KB)

    Results are presented on families of balanced binary error-correcting codes that extend those in the literature. The idea is to consider balanced blocks as symbols over an alphabet and to construct error-correcting codes over that alphabet. Encoding and decoding procedures are presented. Several improvements to the general construction are discussed View full abstract»

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  • Coset codes for partial response channels; or, coset codes with spectral nulls

    Publication Year: 1989, Page(s):925 - 943
    Cited by:  Papers (68)  |  Patents (28)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1848 KB)

    Known coset codes are adapted for use on partial response channels or to generate signals with spectral nulls. By using coset precoding and running digital sum feedback, any desired tradeoff can be achieved between the power and spectra of the relevant sequences, up to the optimum tradeoff possible. A fundamental theorem specifying this optimum tradeoff is given. A maximum-likelihood-sequence-esti... View full abstract»

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  • Convergence in neural memories

    Publication Year: 1989, Page(s):1069 - 1072
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (328 KB)

    One of the simplest optimization problems solved by Ising spin models of neural memory is associative memory retrieval. The authors study deterministic convergence properties of the Hopfield synchronous retrieval algorithm for such models. In this case a memory, stored in the network by an appropriate choice of connections, is retrieved by setting the neural outputs to the binary pattern of the re... View full abstract»

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  • Cutoff rate for the M-ary PSK modulation channel with optimal quantum detection

    Publication Year: 1989, Page(s):1131 - 1133
    Cited by:  Papers (23)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (212 KB)

    The cutoff rate R0 of an optical channel transmitting M-ary phase-shift-keyed coherent states is calculated for a receiver using the optimum quantum detector. This is shown to be nearly equivalent, when M≫1, to a system that measures the phase of the received signal. A closed-form expression yielding a good approximation to R0 is derived View full abstract»

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  • Recursive density estimation under dependence

    Publication Year: 1989, Page(s):1103 - 1108
    Cited by:  Papers (21)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (464 KB)

    Recursive estimators of the density of weakly dependent random variables are studied under certain absolute regularity and strong mixing conditions. Uniform strong consistency of the density estimators is established, and their rates of convergence are obtained. This study is concerned more with the almost sure uniform consistency of a sequence and its rate of convergence than with pointwise conve... View full abstract»

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  • Information rates for magnetic recording channels with peak- and slope-limited magnetization

    Publication Year: 1989, Page(s):956 - 962
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (484 KB)

    A model for magnetic recording is proposed which uses two parameters to describe the limitations on the remanent magnetization in the medium: the dimensionless peak value Am and the steepest slope B(s-1). A low-pass bandwidth restriction W(s-1) due to read circuits is also included. Lower and upper bounds on the achievab... View full abstract»

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  • Extension of an entropy property for binary input memoryless symmetric channels

    Publication Year: 1989, Page(s):1077 - 1079
    Cited by:  Papers (16)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (256 KB)

    The channel output entropy property introduced by A.D. Wyner and J. Ziv (ibid., vol.IT-19, p.769-762, Nov.1973) for a binary symmetric channel is extended to arbitrary memoryless symmetric channels with binary inputs and discrete or continuous outputs. This yields lower bounds on the achievable information rates of these channels under constrained binary inputs. Using the interpretation of entropy... View full abstract»

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  • Neural networks, error-correcting codes, and polynomials over the binary n-cube

    Publication Year: 1989, Page(s):976 - 987
    Cited by:  Papers (57)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (908 KB)

    Several ways of relating the concept of error-correcting codes to the concept of neural networks are presented. Performing maximum-likelihood decoding in a linear block error-correcting code is shown to be equivalent to finding a global maximum of the energy function of a certain neural network. Given a linear block code, a neural network can be constructed in such a way that every codeword corres... View full abstract»

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  • Encoding algorithms for complex approximations in Z[e 2πi/8]

    Publication Year: 1989, Page(s):1133 - 1136
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (272 KB)

    Two algorithms are presented that approximate complex numbers by elements of the algebraic integers of Q(w) where w =e2πi/8. These algorithms substantially reduce the computational burden. Range and memory requirements are given as a function of the desired accuracy, and expressions are obtained for the number of computations required by each algor... View full abstract»

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  • Upper bounds on capacity for a constrained Gaussian channel

    Publication Year: 1989, Page(s):1079 - 1084
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (524 KB)

    A low-pass and a bandpass additive white Gaussian noise channel with a peak-power constraint imposed on otherwise arbitrary input signals are considered. Upper bounds on the capacity of such channels are derived. They are strictly less than the capacity of the channel when the peak-power constrain is removed and replaced by the average-power constraint, for which the Gaussian inputs are optimum. T... View full abstract»

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  • An information theoretic approach to the distributed detection problem

    Publication Year: 1989, Page(s):988 - 994
    Cited by:  Papers (45)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (480 KB)

    The distributed detection problem is considered from an information-theoretic point of view. An entropy-based cost function is used for system optimization. This cost function maximizes the amount of information transfer between the input and the output. Distributed detection system topologies with and without a fusion center are considered, and an optimal fusion rule and optimal decision rules ar... 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