IEEE Transactions on Information Theory

Issue 6 • Nov. 1994

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Displaying Results 1 - 25 of 40
  • Rotationally invariant nonlinear trellis codes for two-dimensional modulation

    Publication Year: 1994, Page(s):1773 - 1791
    Cited by:  Papers (15)  |  Patents (11)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1616 KB)

    A general parity-check equation is presented that defines rotationally invariant trellis codes of rate k/(k+1) for two-dimensional signal sets. This parity-check equation is used to find rate k/(k+1) codes for 4PSK, 8PSK, 16PSK, and QAM signal sets by systematic code searches. The MPSK codes exhibit smaller free Euclidean distances than nonrotationally invariant linear codes with the same number o... View full abstract»

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  • Erasure-free sequential decoding of trellis codes

    Publication Year: 1994, Page(s):1803 - 1817
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1418 KB)

    An erasure-free sequential decoding algorithm for trellis codes, called the buffer looking algorithm (BLA), is introduced. Several versions of the algorithm can be obtained by choosing certain parameters and selecting a resynchronization scheme. These can be categorized as block decoding or continuous decoding, depending on the resynchronization scheme. Block decoding is guaranteed to resynchroniz... View full abstract»

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  • On communication complexity of vector-valued functions

    Publication Year: 1994, Page(s):2062 - 2067
    Cited by:  Papers (20)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (484 KB)

    New upper and lower bounds on the two-way communication complexity of abstract functions g:ℋ×𝒴→𝒵 give tight bounds, when applied to vector-valued functions fn(f1 ,...,fn):ℋu×𝒴n →𝒵n, if the alphabets are small. For the set-intersection function, an optimal protocol is presented. It ... View full abstract»

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  • Variable-rate source coding theorems for stationary nonergodic sources

    Publication Year: 1994, Page(s):1920 - 1925
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (412 KB)

    For a stationary ergodic source, the source coding theorem and its converse imply that the optimal performance theoretically achievable by a fixed-rate or variable-rate block quantizer is equal to the distortion-rate function, which is defined as the infimum of an expected distortion subject to a mutual information constraint. For a stationary nonergodic source, however, the. Distortion-rate funct... View full abstract»

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  • Intersecting codes and independent families

    Publication Year: 1994, Page(s):1872 - 1881
    Cited by:  Papers (35)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (848 KB)

    A binary intersecting code is a linear code with the property that any two nonzero codewords have intersecting supports. These codes appear in a wide variety of contexts and applications, e.g., multiple access, cryptography, and information theory. This paper is devoted partly to the study of intersecting codes, and partly to their use in constructing large t-independent families of binary vectors... View full abstract»

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  • Shannon-theoretic approach to a Gaussian cellular multiple-access channel

    Publication Year: 1994, Page(s):1713 - 1727
    Cited by:  Papers (461)  |  Patents (8)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (960 KB)

    We obtain Shannon-theoretic limits for a very simple cellular multiple-access system. In our model the received signal at a given cell site is the sum of the signals transmitted from within that cell plus a factor α (0⩽α⩽1) times the sum of the signals transmitted from the adjacent cells plus ambient Gaussian noise. Although this simple model is scarcely realistic, it neverthel... View full abstract»

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  • A mapping approach to rate-distortion computation and analysis

    Publication Year: 1994, Page(s):1939 - 1952
    Cited by:  Papers (62)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1136 KB)

    In rate-distortion theory, results are often derived and stated in terms of the optimizing density over the reproduction space. In this paper, the problem is reformulated in terms of the optimal mapping from the unit interval with Lebesgue measure that would induce the desired reproduction probability density. This results in optimality conditions that are “random relatives” of the kno... View full abstract»

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  • Shaping of multidimensional signal constellations using a lookup table

    Publication Year: 1994, Page(s):2058 - 2062
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (432 KB)

    This paper describes a lookup table for the addressing of an optimally shaped constellation. The method is based on partitioning the subconstellations into shaping macro-shells of integer bit rate and increasing average energy. The macro-shells do not need to have an equal number of points. A lookup table is used to select a subset of the partitions in the cartesian product space. By devising appr... View full abstract»

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  • Variance of a generalized polarity-coincidence spectral-centroid estimator for Gaussian processes

    Publication Year: 1994, Page(s):2045 - 2048
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (432 KB)

    The polarity coincidence estimator of the spectral centroid counts the net number of times the phasor of a stationary Gaussian process crosses a chosen phase-reference straight line through the origin during a time T. By following Pawula's (1968) approach, the covariance of two different simultaneous polarity-coincidence estimates having distinct phase reference lines is derived. This basic result... View full abstract»

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  • A communication channel modeled on contagion

    Publication Year: 1994, Page(s):2035 - 2041
    Cited by:  Papers (38)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (616 KB)

    We introduce a binary additive communication channel with memory. The noise process of the channel is generated according to the contagion model of G. Polya (1923); our motivation is the empirical observation of Stapper et al. (1980) that defects in semiconductor memories are well described by distributions derived from Polya's urn scheme. The resulting channel is stationary but not ergodic, and i... View full abstract»

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  • On the asymptotic tightness of the Shannon lower bound

    Publication Year: 1994, Page(s):2026 - 2031
    Cited by:  Papers (70)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (512 KB)

    New results are proved on the convergence of the Shannon (1959) lower bound to the rate distortion function as the distortion decreases to zero. The key convergence result is proved using a fundamental property of informational divergence. As a corollary, it is shown that the Shannon lower bound is asymptotically tight for norm-based distortions, when the source vector has a finite differential en... View full abstract»

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  • Power moment derivation for noisy phase lightwave systems

    Publication Year: 1994, Page(s):2099 - 2103
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (348 KB)

    The distribution law of the Brownian motion exponential functional: ε=|f[0,1]exp[j√(2βWt]dt|2 ), where {Wt,t∈ℛ+} is a standard Brownian motion, modeling the laser's phase noise, plays a key role in many of the proposed heterodyne lightwave systems. The exact analytic derivation of these statistics appears to be, howev... View full abstract»

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  • Universal coding for the Slepian-Wolf data compression system and the strong converse theorem

    Publication Year: 1994, Page(s):1908 - 1919
    Cited by:  Papers (36)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (712 KB)

    Universal coding for the Slepian-Wolf (1973) data compression system is considered. We shall demonstrate based on a simple observation that the error exponent given by Csiszar and Korner (1980) for the universal coding system can strictly be sharpened in general for a region of relatively higher rates. This kind of observation can be carried over also to the case of lower rates outside the Slepian... View full abstract»

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  • Density/length profiles and trellis complexity of lattices

    Publication Year: 1994, Page(s):1753 - 1772
    Cited by:  Papers (29)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1492 KB)

    The density/length profile (DCP) of a lattice Λ is analogous to the dimension/length profile of a linear code. The DLP is a geometrical invariant of Λ that includes the coding gain of Λ. Duality results analogous to those of linear block codes are derived for lattices. Bounds on the DLP may be derived from bounds on Hermite's constants; these hold with equality for many dense ... View full abstract»

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  • A sequential procedure for multihypothesis testing

    Publication Year: 1994, Page(s):1994 - 2007
    Cited by:  Papers (132)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (972 KB)

    The sequential testing of more than two hypotheses has important applications in direct-sequence spread spectrum signal acquisition, multiple-resolution-element radar, and other areas. A useful sequential test which we term the MSPRT is studied in this paper. The test is shown to be a generalization of the sequential probability ratio test. Under Bayesian assumptions, it is argued that the MSPRT a... View full abstract»

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  • Upper bounds on generalized distances

    Publication Year: 1994, Page(s):2090 - 2092
    Cited by:  Papers (21)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (232 KB)

    We derive new asymptotic bounds for generalized distances. Our approach extends the classical Hamming, Plotkin, and Elias bounds. The latter bound involves extending the definition of generalized distances to nonlinear codes View full abstract»

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  • On the general defective channel with informed encoder and capacities of some constrained memories

    Publication Year: 1994, Page(s):1866 - 1871
    Cited by:  Papers (20)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (532 KB)

    From an information-theoretical point of view the write once memory (WOM), the unidirectional memory (WUM), the write isolated memory (WIM), the memory with address faults (MAF), Blackwell's broadcast channel, and some other constrained memories and channels with an informed encoder can be considered as particular cases of the general defective channel (GDC) introduced by Kuznetsov (1983) as a gen... View full abstract»

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  • Weight distributions of some binary primitive cyclic codes

    Publication Year: 1994, Page(s):2068 - 2071
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (304 KB)

    Let s and k be integers such that s is a divisor of 2k-1. Let g(x) be a divisor of xs-1 over F2 , and let π(x) be a primitive polynomial of degree k over F2. We consider the binary cyclic code C of length N=2k -1 generated by (XN-1)/g(x)π(x). For special cases, we determine the weight distribution of C by using the weights of ... View full abstract»

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  • Asymptotic bounds on optimal noisy channel quantization via random coding

    Publication Year: 1994, Page(s):1926 - 1938
    Cited by:  Papers (33)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (980 KB)

    Asymptotically optimal zero-delay vector quantization in the presence of channel noise is studied using random coding techniques. First, an upper bound is derived for the average rth-power distortion of channel optimized k-dimensional vector quantization at transmission rate R on a binary symmetric channel with bit error probability ε. The upper bound asymptotically equals 2-rRg(ε,k... View full abstract»

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  • Superimposed codes in the Hamming space

    Publication Year: 1994, Page(s):1882 - 1893
    Cited by:  Papers (4)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (876 KB)

    We consider the problem of simultaneous identification and transmission of information by means of superimposed codes. It is assumed that a total population of T users share a common channel. At each time at most in of the T users are active. The output from the channel is the modulo-2 sum of the binary codewords transmitted by the active users, possibly disturbed by errors. A superimposed code is... View full abstract»

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  • Rates of convergence in the source coding theorem, in empirical quantizer design, and in universal lossy source coding

    Publication Year: 1994, Page(s):1728 - 1740
    Cited by:  Papers (54)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1040 KB)

    Rate of convergence results are established for vector quantization. Convergence rates are given for an increasing vector dimension and/or an increasing training set size. In particular, the following results are shown for memoryless real-valued sources with bounded support at transmission rate R. (1) If a vector quantizer with fixed dimension k is designed to minimize the empirical mean-square er... View full abstract»

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  • On information rates for mismatched decoders

    Publication Year: 1994, Page(s):1953 - 1967
    Cited by:  Papers (192)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1244 KB)

    Reliable transmission over a discrete-time memoryless channel with a decoding metric that is not necessarily matched to the channel (mismatched decoding) is considered. It is assumed that the encoder knows both the true channel and the decoding metric. The lower bound on the highest achievable rate found by Csiszar and Korner (1981) and by Hui (1983) for DMC's, hereafter denoted CLM, is... View full abstract»

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  • A differential equation approach to the computation of the Fourier transform of the images of translating objects

    Publication Year: 1994, Page(s):2049 - 2058
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (664 KB)

    The frequency domain analysis of constant velocity motion has proven useful in a number of different contexts ranging from television signal processing to computer vision. This work considers the frequency domain analysis of a generalization of such simple dynamics, which includes the effect of acceleration and its time derivatives (of any order). In the frequency domain the contribution due to th... View full abstract»

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  • Coding theorems for a continuous-time Gaussian channel with feedback

    Publication Year: 1994, Page(s):2041 - 2045
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (412 KB)

    The main aim of the paper is to prove a coding theorem for a continuous-time Gaussian channel with feedback, under an average power constraint. In the case of discrete-time, the coding theorem for the feedback Gaussian channel has been shown by Cover and Pombra (1989) View full abstract»

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  • Rate-distortion function when side-information may be present at the decoder

    Publication Year: 1994, Page(s):2031 - 2034
    Cited by:  Papers (63)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (320 KB)

    A discrete memoryless source {Xk} is to be coded into a binary stream of rate R bits/symbol such that {Xk} can be recovered with minimum possible distortion. The system is to be optimized for best performance with two decoders, one of which has access to side-information about the source. For given levels of average distortion for these two decoders, the minimum achievable ra... View full abstract»

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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