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IBM Journal of Research and Development

Issue 5 • Date Sept. 1983

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Displaying Results 1 - 10 of 10
  • Periodic Sequences with Optimal Properties for Channel Estimation and Fast Start-Up Equalization

    Publication Year: 1983, Page(s):426 - 431
    Cited by:  Papers (110)  |  Patents (22)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (432 KB)

    The problems of fast channel estimation and fast start-up equalization in synchronous digital communication systems are considered from the viewpoint of the optimization of the training sequence to be transmitted. Various types of periodic sequences having uniform discrete power spectra are studied. Some of them are new and may be generated with data sets commonly used in phase modulation systems.... View full abstract»

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  • An Analysis of the Tolerance to Crosstalk Noise of a Pulse Width Modulation System

    Publication Year: 1983, Page(s):432 - 439
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (527 KB)

    This paper reports the results of an investigation to determine the drive degradation caused by random noise in a pulse width modulation (PWM) system originally designed for communicating on coaxial cable but using instead twisted-pair cables. Presented are the analysis of the driver/receiver circuit, the theoretical modeling of the transmitted waveforms over the twisted-pair medium using ASTAP, a... View full abstract»

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  • A DC-Balanced, Partitioned-Block, 8B/10B Transmission Code

    Publication Year: 1983, Page(s):440 - 451
    Cited by:  Papers (175)  |  Patents (140)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1001 KB)

    This paper describes a byte-oriented binary transmission code and its implementation. This code is particularly well suited for high-speed local area networks and similar data links, where the information format consists of packets, variable in length, from about a dozen up to several hundred 8-bit bytes. The proposed transmission code translates each source byte into a constrained 10-bit binary s... View full abstract»

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  • Some Methods for Providing OSI Transport in SNA

    Publication Year: 1983, Page(s):452 - 463
    Cited by:  Papers (5)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1019 KB)

    This paper is made up of three parts: first, a review of open systems interconnection (OSI) objectives, followed by a comparison/contrasting of OSI and systems network architecture (SNA) objectives; second, a description of techniques for providing communication between programs residing in systems based on different architectures; and third, the possible application of these techniques to the fou... View full abstract»

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  • Address-Independent Routing for Local Networks

    Publication Year: 1983, Page(s):464 - 471
    Cited by:  Patents (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (568 KB)

    A routing methodology is introduced which permits messages to be propagated throughout a network without recourse to destination or origin addresses. Two classes of networks, bidirectional trees and augmented rings, are analyzed from this point of view. An optimality property is proved for the bidirectional tree, and three types of address-independent routing strategies are derived. It is shown th... View full abstract»

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  • Simulation of Non-Markovian Systems

    Publication Year: 1983, Page(s):472 - 480
    Cited by:  Papers (4)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (668 KB)

    A generalized semi-Markov process provides a stochastic process model for a discrete-event simulation. This representation is particularly useful for non-Markovian systems where it is nontrivial to obtain recurrence properties of the underlying stochastic processes. We develop “geometric trials” arguments which can be used to obtain results on recurrence and regeneration in this sett... View full abstract»

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  • A Local Communications Network Based on Interconnected Token-Access Rings: A Tutorial

    Publication Year: 1983, Page(s):481 - 496
    Cited by:  Papers (9)  |  Patents (7)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1212 KB)

    Local area networks are expected to provide the communications base for interconnecting computer equipment and terminals over the next decade. The primary objective of a local area network (LAN) is to provide high-speed data transfer among a group of nodes consisting of data-processing terminals, controllers, or computers within the confines of a building or campus environment. The network should ... View full abstract»

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  • Optimization of Relational Expressions Using A Logical Analogon

    Publication Year: 1983, Page(s):497 - 519
    Cited by:  Patents (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1407 KB)

    An expression applying to a relational database is optimized by mapping the expression upon set expressions which, in turn, are transformed into logical expressions. These logical expressions then are optimized, taking into account the constraints that are inherent in relational expressions and the costs of those expressions. Subsequently a reverse transformation to relational expressions is appli... View full abstract»

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  • Recent Papers by IBM Authors

    Publication Year: 1983, Page(s):520 - 526
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (594 KB)

    Reprints of the papers listed here may usually be obtained by writing directly to the authors. The authors' IBM divisions or groups are identified as follows: CHQ is Corporate Headquarters; CPD, Communication Products Division: DSD, Data Systems Division; FED, Field Engineering Division; FSD, Federal Systems Division; GPD, General Products Division; GSD, General Systems Division; GTD, General Tech... View full abstract»

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  • Recent IBM Patents

    Publication Year: 1983, Page(s):527 - 528
    IEEE is not the copyright holder of this material | PDF file iconPDF (206 KB)
    Freely Available from IEEE

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The IBM Journal of Research and Development is a peer-reviewed technical journal, published bimonthly, which features the work of authors in the science, technology and engineering of information systems.

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Clifford A. Pickover
IBM T. J. Watson Research Center