Scheduled System Maintenance
On Saturday, December 10, single article sales and account management will be unavailable from 5:00 AM-7:30 PM ET.
We apologize for the inconvenience.
By Topic

IEEE Transactions on Information Theory

Issue 4 • May 1999

Filter Results

Displaying Results 1 - 25 of 37
  • Contributors

    Publication Year: 1999, Page(s):1351 - 1357
    Request permission for commercial reuse | PDF file iconPDF (60 KB)
    Freely Available from IEEE
  • Cyclic codes and self-dual codes over F2+uF2

    Publication Year: 1999, Page(s):1250 - 1255
    Cited by:  Papers (58)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (268 KB)

    We introduce linear cyclic codes over the ring F2+uF 2={0,1,u,u¯=u+1}, where u2=0 and study them by analogy with the Z4 case. We give the structure of these codes on this new alphabet. Self-dual codes of odd length exist as in the case of Z4-codes. Unlike the Z4 case, here free codes are not interesting. Some nonfree codes give... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Two recursive algorithms for computing the weight distribution of certain irreducible cyclic codes

    Publication Year: 1999, Page(s):1244 - 1249
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (228 KB)

    Two recursive algorithms for computing the weight distributions of certain binary irreducible cyclic codes of length n in the so-called index 2 case are presented. The running times of these algorithms are smaller than O(log2r) where r=2m and n is a factor of r-1 View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • New classes of cyclic extended Goppa codes

    Publication Year: 1999, Page(s):1264 - 1266
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (116 KB)

    We give a condition for a “classical” Goppa (1970) code to have a cyclic extension. This condition follows from the properties of the semilinear automorphism group of the corresponding generalized Reed-Solomon codes. Using this condition, we can construct not only all the known Goppa codes with a cyclic extension, but also new families View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Fast universal coding with context models

    Publication Year: 1999, Page(s):1065 - 1071
    Cited by:  Papers (10)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (164 KB)

    A universal code using context models is constructed, which is optimal in the strong sense that the mean per symbol code length approaches asymptotically the entropy of any data generating tree machine at the fastest possible rate. The number of coding operations required is O (n log log n) for a string of length n, which is much less than in the earlier codes using context models. This is made po... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On some cosets of the first-order Reed-Muller code with high minimum weight

    Publication Year: 1999, Page(s):1237 - 1243
    Cited by:  Papers (19)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (316 KB)

    We study a family of particular cosets of the first-order Reed-Muller code R(1,m): those generated by special codewords, the idempotents. Thus we obtain new maximal weight distributions of cosets of R(1,7) and 84 distinct almost maximal weight distributions of cosets of R(1,9), that is, with minimum weight 240. This leads to crypotographic applications in the context of stream ciphers View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Algorithm for calculating the noncentral chi-square distribution

    Publication Year: 1999, Page(s):1327 - 1333
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (232 KB)

    This article presents a new algorithm for evaluating the noncentral chi-square distribution based on Parl's (1980) method of Neumann series expansion. It is applicable to both even and odd degrees of freedom, unlike most prior work, which has been directed at the even cases. Convergence tests and procedures for detection of loss of precision are given. The overall method is extremely simple to pro... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Estimation of the information by an adaptive partitioning of the observation space

    Publication Year: 1999, Page(s):1315 - 1321
    Cited by:  Papers (138)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (300 KB)

    We demonstrate that it is possible to approximate the mutual information arbitrarily closely in probability by calculating the relative frequencies on appropriate partitions and achieving conditional independence on the rectangles of which the partitions are made. Empirical results, including a comparison with maximum-likelihood estimators, are presented View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • New upper bounds on generalized weights

    Publication Year: 1999, Page(s):1258 - 1263
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (240 KB)

    We derive new asymptotic upper bounds on the generalized weights of a binary linear code of a given size. We also prove some asymptotic results on the distance distribution of binary codes View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Upper bounds on the size of quantum codes

    Publication Year: 1999, Page(s):1206 - 1215
    Cited by:  Papers (25)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (248 KB)

    This paper is concerned with bounds for quantum error-correcting codes. Using the quantum MacWilliams (1972, 1977) identities, we generalize the linear programming approach from classical coding theory to the quantum case. Using this approach, we obtain Singleton-type, Hamming-type, and the first linear-programming-type bounds for quantum codes. Using the special structure of linear quantum codes,... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Multiple packing of the Euclidean sphere

    Publication Year: 1999, Page(s):1334 - 1337
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (172 KB)

    We obtain bounds for the cardinality of multiple packing of the Euclidean sphere. At zero rate these bounds are tight View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimal binary one-error-correcting codes of length 10 have 72 codewords

    Publication Year: 1999, Page(s):1229 - 1231
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (88 KB)

    The maximum number of codewords in a binary code with length n and minimum distance d is denoted by A(n, d). By construction it is known that A(10, 3)⩾72 and A(11, 3)⩾144. These bounds have long been conjectured to be the exact values. This is here proved by classifying various codes of smaller length and lengthening these using backtracking and isomorphism rejection. There are 562 inequiv... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Constructions of intersecting codes

    Publication Year: 1999, Page(s):1234 - 1237
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (160 KB)

    New constructions of binary linear intersecting codes are presented. Some codes with high distances are shown to be intersecting View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Constructions of algebraic-geometry codes

    Publication Year: 1999, Page(s):1186 - 1193
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (236 KB)

    Based on curves over finite fields with many rational points, we present two constructions of linear codes from local expansions of functions at a fixed rational point. It turns out that codes from our constructions have the same bound on their parameters as Goppa's (1981) geometry codes. Furthermore, we prove that our second construction is equivalent to Goppa's construction. Finally, an addition... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance of LZ algorithms on individual sequences

    Publication Year: 1999, Page(s):1283 - 1288
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (224 KB)

    The performance of three versions of the Lempel-Ziv (1976) algorithm on individual sequences is investigated. It is shown that as the restart length goes to infinity, each compresses an individual sequence as well as any block-to-variable finite-state information lossless algorithm, and that the same conclusion holds for sliding-window LZ as the window width goes to infinity. Examples are given sh... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Maximum entropy and robust prediction on a simplex

    Publication Year: 1999, Page(s):1150 - 1164
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (380 KB)

    The related problems of (finite-length) robust prediction and maximizing spectral entropy over a simplex of covariance matrices are considered. General properties of iterative solutions of these problems are developed, and monotone convergence proofs are presented for two algorithms that provide such solutions. The analogous problems for simplexes of spectral densities are also considered View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Periodic binary sequences with the "trinomial property"

    Publication Year: 1999, Page(s):1276 - 1279
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (196 KB)

    Periodic binary sequences with the "trinomial property" are considered. Some necessary and sufficient conditions for "trinomial pairs" of a nonlinear sequence of period 2n-1 as well as classifications for trinomial pairs are derived. Complete searches for trinomial pairs of sequences have been completed for 3≤n≤17. We list them here for n≤12. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Rapid encoding of run lengths and pyramid cubic lattices

    Publication Year: 1999, Page(s):1347 - 1350
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (140 KB)

    We can encode rare events with an overhead of about 1.56 bits/event. The contribution of the overhead to the total length of the code is negligible. The encoding and decoding time counted in operations over bits per bit of the code does not depend on the number of appearances of the events. We also present algorithms of the same speed which enumerate the pyramid cubic lattices with an overhead of ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Structured prefix codes for quantized low-shape-parameter generalized Gaussian sources

    Publication Year: 1999, Page(s):1307 - 1314
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (288 KB)

    The highly peaked wide-tailed pdf's that are encountered in many image coding algorithms are often modeled using the family of generalized Gaussian (GG) pdf's. We study entropy coding of quantized GG sources using prefix codes that are highly structured, and which therefore involve low computational complexity. We provide bounds for the redundancy associated with applying these codes to quantized ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Combined array processing and space-time coding

    Publication Year: 1999, Page(s):1121 - 1128
    Cited by:  Papers (331)  |  Patents (41)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (176 KB)

    The information capacity of wireless communication systems may be increased dramatically by employing multiple transmit and receive antennas. The goal of system design is to exploit this capacity in a practical way. An effective approach to increasing data rate over wireless channels is to employ space-time coding techniques appropriate to multiple transmit antennas. These space-time codes introdu... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Further results on generalized Hamming weights for Goethals and Preparata codes over Z4

    Publication Year: 1999, Page(s):1255 - 1258
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (192 KB)

    This article contains results on the generalized Hamming weights (GHW) for the Goethals and Preparata codes over Z4. We give an upper bound on the rth generalized Hamming weights dr(m,j) for the Goethals code Gm(j) of length 2m over Z 4, when m is odd. We also determine d3.5(m,j) exactly. The upper bound is shown to be tight up to r... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Sequences with almost perfect linear complexity profiles and curves over finite fields

    Publication Year: 1999, Page(s):1267 - 1270
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (140 KB)

    For stream ciphers, we need to generate pseudorandom sequences which are of properties of unpredictability and randomness. A important measure of unpredictability and randomness is the linear complexity profile (l.c.p.) la(n) of a sequence a. A sequence a is called almost perfect if the l.c.p. is la(n)=n/2+O(1). Based on curves over finite fields, we present a method to const... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Random coding error exponents for two-dimensional flat fading channels with complete channel state information

    Publication Year: 1999, Page(s):1338 - 1346
    Cited by:  Papers (21)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (368 KB)

    In this correspondence, we consider the random coding error exponent for nondispersive two-dimensional (2-D) (quadrature) fading channels for which the channel state information (CSI) is perfectly known at the receiver and the input to the transmitter is constrained in its average power. Also, the effect of space diversity on improving the performance is demonstrated. The results obtained in this ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Entropy computations via analytic depoissonization

    Publication Year: 1999, Page(s):1072 - 1081
    Cited by:  Papers (32)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (296 KB)

    We investigate the basic question of information theory, namely, evaluation of Shannon entropy, and a more general Renyi (1961) entropy, for some discrete distributions (e.g., binomial, negative binomial, etc.). We aim at establishing analytic methods (i.e., those in which complex analysis plays a pivotal role) for such computations which often yield estimates of unparalleled precision. The main a... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Type II codes, even unimodular lattices, and invariant rings

    Publication Year: 1999, Page(s):1194 - 1205
    Cited by:  Papers (48)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (368 KB)

    We study self-dual codes over the ring Z2k of the integers modulo 2k with relationships to even unimodular lattices, modular forms, and invariant rings of finite groups. We introduce Type II codes over Z2k which are closely related to even unimodular lattices, as a remarkable class of self-dual codes and a generalization of binary Type II codes. A construction of even unimodu... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

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
Frank R. Kschischang

Department of Electrical and Computer Engineering