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IEEE Transactions on Information Theory

Issue 4 • Date July 1996

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Displaying Results 1 - 25 of 37
  • Fundamentals of Artificial Neural Networks [Book Reviews]

    Publication Year: 1996
    Cited by:  Papers (2)  |  Patents (1)
    Request permission for commercial reuse | PDF file iconPDF (424 KB)
    Freely Available from IEEE
  • On determining the radar threshold for non-Gaussian processes from experimental data

    Publication Year: 1996, Page(s):1310 - 1316
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (612 KB)

    The problem of detecting radar signals embedded in clutter is an area of great interest. In many radar applications, it is important to set thresholds to achieve a false alarm probability (PF) of 10-5 or lower. Using conventional Monte Carlo techniques, where thresholds are set based on raw percentiles, an extremely large number of samples is required. We use the generalized ... View full abstract»

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  • On the convergence of linear stochastic approximation procedures

    Publication Year: 1996, Page(s):1305 - 1309
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (328 KB)

    Many stochastic approximation procedures result in a stochastic algorithm of the form hk+1=hk+1/k(bk-A khk), for all k=1,2,3,... . Here, {bk,k=1,2,3...} is a Rd-valued process, {Ak,k=1,2,3,...} is a symmetric, positive semidefinite R ed×d-valued process, and {hk,k=1... View full abstract»

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  • Vanishing distortion and shrinking cells

    Publication Year: 1996, Page(s):1303 - 1305
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (268 KB)

    We establish an asymptotic connection between vanishing rth-power distortion and shrinking cell diameters for vector quantizers with convex cells. As a consequence, a number of shrinking cell conditions may be easily verified by showing that the quantizers in question have distortion tending to zero. This also plays an important role in the asymptotic analysis of a common greedy growing scheme for... View full abstract»

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  • A hierarchical dynamic programming approach to fixed-rate, entropy-coded quantization

    Publication Year: 1996, Page(s):1298 - 1303
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (608 KB)

    In quantization of any source with a nonuniform probability density function, the entropy coding of the quantizer output can result in a substantial decrease in bit rate. A straightforward entropy coding scheme faces us with the problem of variable data rate. A solution in a space of dimensionality N is to select an appropriate subset of elements in the N-fold Cartesian product of a scalar quantiz... View full abstract»

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  • Optimal quaternary linear codes of dimension five

    Publication Year: 1996, Page(s):1228 - 1235
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (516 KB)

    Let dq(n,k) be the maximum possible minimum Hamming distance of a q-ary [n,k,d]-code for given values of n and k. It is proved that d4 (33,5)=22, d4(49,5)=34, d4 (131,5)=96, d4(142,5)=104, d4(147,5)=108, d 4(152,5)=112, d4(158,5)=116, d4(176,5)⩾129, d4(180,5)⩾132, d4(190... View full abstract»

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  • A directed search approach for unit-memory convolutional codes

    Publication Year: 1996, Page(s):1290 - 1297
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (668 KB)

    A set of heuristic algorithms to numerically search for binary unit-memory convolutional codes (UMC) are presented along with a large number of new codes for 2⩽k⩽8 and code rate 1/4⩽R<1. Combinatorial optimization is used which involves selecting and then pairwise-matching column vectors of the two (n,k) UMC tap weight matrices. The column selection problem is that of finding the be... View full abstract»

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  • Mass formulas for self-dual codes over Z4 and Fq+uFq rings

    Publication Year: 1996, Page(s):1222 - 1228
    Cited by:  Papers (21)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (492 KB)

    We give a mass formula for quaternary self-dual and type II codes and for self-dual codes over Fq+uFq rings. We define type II codes and compute the number of distinct type II codes. We also give formulas for the number of doubly even binary codes, necessary to compute Nd(n), the number of distinct codes of length n, for any dimension n, and conc... View full abstract»

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  • Application of set-membership techniques to symbol-by-symbol decoding for binary data-transmission systems

    Publication Year: 1996, Page(s):1285 - 1290
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (656 KB)

    The application of set theory methods to problems in estimation, system identification, and classification is emerging as a viable approach to a number of different problems. This correspondence studies the use of set-membership methods in symbol-by-symbol decoding of binary data in data-transmission systems. Theorems for necessary and sufficient conditions for error-free decoding are presented. F... View full abstract»

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  • Optimal binary linear codes and Z4-linearity

    Publication Year: 1996, Page(s):1216 - 1222
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (608 KB)

    We give necessary and sufficient conditions for a binary linear code to be Z4-linear. Especially we treat optimal, binary linear codes and determine all such codes with minimum weight less or equal to six which are Z4-linear View full abstract»

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  • Analysis of convolutional encoders and synthesis of rate-2/n Viterbi decoders

    Publication Year: 1996, Page(s):1280 - 1285
    Cited by:  Papers (2)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (704 KB)

    In this correspondence, the problem of obtaining efficient hardware for Viterbi decoders for high-rate convolutional encoders is addressed. It is first shown that the graphs describing the interconnection of the add-compare-select units required may be classified in terms of structures of which there are only a small number for a given code constraint length. They correspond to the assignment of i... View full abstract»

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  • Some remarks on an algorithm of Fitzpatrick

    Publication Year: 1996, Page(s):1269 - 1271
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (284 KB)

    Fitzpatrick's algorithm for solving the classical Reed-Solomon key equation is shown to be related to an algorithm for solving the Welch-Berlekamp key equation. It can be made more efficient when decoding binary BCH codes. Its efficiency is about the same as for the Berlekamp-Massey algorithm View full abstract»

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  • Improved estimates via exponential sums for the minimum distance of Z4-linear trace codes

    Publication Year: 1996, Page(s):1212 - 1216
    Cited by:  Papers (17)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (356 KB)

    An upper hound for Weil-type exponential sums over Galois rings was derived by Kumar, Helleseth, and Calderbank (see ibid., vol.41, no.3, p.456, 1995). This bound leads directly to an estimate for the minimum distance of Z4-linear trace codes. An improved minimum-distance estimate is presented. First, McEliece's result on the divisibility of the weights of binary cyclic codes is extende... View full abstract»

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  • Partially hidden Markov models

    Publication Year: 1996, Page(s):1253 - 1256
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (364 KB)

    Partially hidden Markov models (PHMM) are introduced. They differ from the ordinary HMMs in that both the transition probabilities of the hidden states and the output probabilities are conditioned on past observations. As an illustration they are applied to black and white image compression where the hidden variables may be interpreted as representing noncausal pixels View full abstract»

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  • Group block codes over nonabelian groups are asymptotically bad

    Publication Year: 1996, Page(s):1277 - 1280
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (372 KB)

    It is known that group block codes over nonabelian groups of order less than 32 are asymptotically bad. In this correspondence we extend that result, showing that group block codes over nonabelian groups are asymptotically bad, no matter what the order of the group under consideration is View full abstract»

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  • A generalized Forney formula for algebraic-geometric codes

    Publication Year: 1996, Page(s):1263 - 1268
    Cited by:  Papers (9)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (504 KB)

    This correspondence contains a straightforward generalization of decoding of BCH codes to the decoding of algebraic-geometric codes, couched in terms of varieties, ideals, and Grobner bases. This consists of 1) a Berlekamp-Massey-type lattice-shifting row-reduction algorithm with majority voting similar to algorithms in the current literature, 2) a realization that it produces a minimal Grobner ba... View full abstract»

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  • On the accuracy of estimating the parameters of a regular stationary process

    Publication Year: 1996, Page(s):1202 - 1211
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (604 KB)

    Any regular stationary random processes can be represented as the sum of a purely indeterministic process and a deterministic one. This paper considers the achievable accuracy in the joint estimation of the parameters of these two components, from a single observed realization of the process. An exact form of the Cramer-Rao bound (CRB) is derived, as well as a conditional CRB. The relationships be... View full abstract»

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  • Analysis of linear prediction, coding, and spectral estimation from subbands

    Publication Year: 1996, Page(s):1160 - 1178
    Cited by:  Papers (40)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1204 KB)

    Linear prediction schemes make a prediction xˆi of a data sample xi using p previous samples. It has been shown by Woods and O'Neil (1986) as well as Pearlman (1991) that as the order of prediction p→∞, there is no gain to be obtained by coding subband samples. This paper deals with the less well understood theory of finite-order prediction and optimal coding ... View full abstract»

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  • A cyclic [6,3,4] group code and the hexacode over GF(4)

    Publication Year: 1996, Page(s):1250 - 1253
    Cited by:  Papers (3)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (396 KB)

    A [6,3,4] code E6 over an Abelian group A4 with four elements is presented. E6 is cyclic, unlike the [6,3,4] hexacode H6 over GF(4). However, E6 and H 6 are isomorphic when the latter is viewed as a group code. Differences and similarities between E6 and H6 are discussed. A dual code of E6 is present... View full abstract»

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  • Multidimensional M-PSK trellis codes for fading channels

    Publication Year: 1996, Page(s):1093 - 1108
    Cited by:  Papers (15)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (908 KB)

    This paper investigates the code search problem for trellis-coded multidimensional phase modulation for Rayleigh fading channels. New set partitionings for multiple phase-shift keying (M-PSK) are proposed using the effective code length (ECL) and the minimum product distance (PD) as the code design criteria. By using these set-partitionings rules, new multidimensional codes which are optimum for R... View full abstract»

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  • On the traveling salesman problem in binary Hamming spaces

    Publication Year: 1996, Page(s):1274 - 1276
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (228 KB)

    Given a subset X of vertices of the n-cube (i.e., the n-dimensional Hamming space), we are interested in the solution of the traveling salesman problem; namely, the minimal length of a cycle passing through all vertices of X. For a given number M, we estimate the maximum of these lengths when X ranges over all possible choices of sets of M vertices. Asymptotically, our estimates show that for a nu... View full abstract»

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  • New single-error-correcting codes

    Publication Year: 1996, Page(s):1261 - 1262
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (188 KB)

    A matrix construction of nonlinear error-correcting codes is considered. It is shown how this construction and some related theorems can be applied to old codes to get new codes with minimum distance 3. In total 13 new binary single-error-correcting codes of length at most 511 are obtained View full abstract»

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  • Minimum entropy of error estimation for discrete random variables

    Publication Year: 1996, Page(s):1193 - 1201
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (684 KB)

    The principle of minimum entropy of error estimation (MEEE) is formulated for discrete random variables. In the case when the random variable to be estimated is binary, we show that the MEEE is given by a Neyman-Pearson-type strictly monotonous test. In addition, the asymptotic behavior of the error probabilities is proved to be equivalent to that of the Bayesian test View full abstract»

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  • On lattice quantization noise

    Publication Year: 1996, Page(s):1152 - 1159
    Cited by:  Papers (148)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (648 KB)

    We present several results regarding the properties of a random vector, uniformly distributed over a lattice cell. This random vector is the quantization noise of a lattice quantizer at high resolution, or the noise of a dithered lattice quantizer at all distortion levels. We find that for the optimal lattice quantizers this noise is wide-sense-stationary and white. Any desirable noise spectra may... View full abstract»

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  • Polyphase Barker sequences up to length 36

    Publication Year: 1996, Page(s):1248 - 1250
    Cited by:  Papers (24)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (284 KB)

    Originally, Barker (1953) presented binary sequences for synchronization purposes in telecommunications. A sequence is called a generalized Barker sequence if the magnitude of all autocorrelation sidelobes is less or equal to one. It is shown that uniform complex sequences up to length 36, meeting the Barker (1953) condition, do exist. Examples are given for length 32-36. The sequences were obtain... 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
Frank R. Kschischang

Department of Electrical and Computer Engineering