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A. Shen - One of the best experts on this subject based on the ideXlab platform.

  • Ieee Journal On Selected Areas In Communications, Vol. 9, No. 6, August 1991
    2007
    Co-Authors: Simulation And Experimental, W.a. Krzymien, Wayne D. Grover, Senior Member, A. Shen
    Abstract:

    We report simulation results and prototype control protocols for a digital subscriber loop transmission system, which will find anti operate at the highest common bidirectional transmission rate that is viable on a given loop while preserving a specified noise margin. A prototype implements the rate-adaptation and transmission protocols over a captive muir|gauge earle facility. Simulation results predict the accompanying symbol rate versus reach characteristics for a transceiver with the same structure as today's basic access (BRA) systems under RA-DSL control. Results predict that 1.5 Mb/s could be deliv- ered to loops up to 2 kin while subscribers out to 10 km could receive 80 kb/s (lB + D service). For a number of specialized or short-notice situations such as Fractional TI service re- quests, n x DS-0 video conferencing, and cable exhaust, RADSL could be the basis for a fast and flexible response vehicle. If RA-DSL cannot serve an individual combination of distance and capacity, existing methods remain. However, a statistical assessment with metro population data shm*s the potential for RA-DSL to satisfy 4-6 times more n x DS-0 access requests than BRA, on existing copper, without carrier serving area constraints

  • Simulation and experimental studies on the concept of a rate-adaptive digital subscriber loop (RA-DSL)
    IEEE Journal on Selected Areas in Communications, 1991
    Co-Authors: Wayne D. Grover, W.a. Krzymien, A. Shen
    Abstract:

    The authors report simulation results and prototype control protocols for a digital subscriber loop transmission system, which will find and operate at the highest common bidirectional transmission rate that is viable on a given loop while preserving a specified noise margin. A prototype implements the rate-adaptation and transmission protocols over a captive multigauge cable facility. Simulation results predict the accompanying symbol rate versus reach characteristics for a transceiver with the same structure as basic rate access (BRA) systems under RA-DSL control. Results show that 1.5 Mb/s could be delivered to loops of up to 2 km while subscribers out to 10 km could receive 80 kb/s. For a number of specialized or short-notice situations, RA-DSL could be the basis for a fast and flexible response vehicle. If RA-DSL cannot serve an individual combination of distance and capacity, existing methods remain. However, a statistical assessment with metro population data shows the potential for RA-DSL to satisfy 4-6 times more n*DS-0 access requests than BRA on existing copper, without carrier serving area constraints. >

  • Turbo-loop: a rate-adaptive digital subscriber loop (RA-DSL) for advanced ISDN access applications
    IEEE Global Telecommunications Conference 1989 and Exhibition. 'Communications Technology for the 1990s and Beyond, 2026
    Co-Authors: W.e. Grover, W.a. Krzymien, T. Fong, A. Shen, J. Dubuc
    Abstract:

    The authors report the implementation of prototype hardware and control protocols which will automatically maximize the transmission rate of individual subscriber loops. The result is a rate-adaptive digital subscriber loop (RA-DSL) technology called Turbo-loop, which makes possible new applications such as a simple form of bandwidth-on-demand and a strategy for increased utilization of existing copper, while bridging the gap to having fiber in the loop. Results predict that Turbo-loop can deliver 1.5 Mb/s up to 2 km, reaching subscribers to 10 km and 80 kb/s, and can provide a potential increase of 400% to 600% in the total utilization of existing copper access networks. The authors describe the hardware and software design of the RA-DSL prototype and report results of adaptive transmission rate experiments on actual copper loops. Also described are simulation studies which predict the ultimate performance of a fully developed design based on the Turbo-loop principle. >

W.a. Krzymien - One of the best experts on this subject based on the ideXlab platform.

  • Ieee Journal On Selected Areas In Communications, Vol. 9, No. 6, August 1991
    2007
    Co-Authors: Simulation And Experimental, W.a. Krzymien, Wayne D. Grover, Senior Member, A. Shen
    Abstract:

    We report simulation results and prototype control protocols for a digital subscriber loop transmission system, which will find anti operate at the highest common bidirectional transmission rate that is viable on a given loop while preserving a specified noise margin. A prototype implements the rate-adaptation and transmission protocols over a captive muir|gauge earle facility. Simulation results predict the accompanying symbol rate versus reach characteristics for a transceiver with the same structure as today's basic access (BRA) systems under RA-DSL control. Results predict that 1.5 Mb/s could be deliv- ered to loops up to 2 kin while subscribers out to 10 km could receive 80 kb/s (lB + D service). For a number of specialized or short-notice situations such as Fractional TI service re- quests, n x DS-0 video conferencing, and cable exhaust, RADSL could be the basis for a fast and flexible response vehicle. If RA-DSL cannot serve an individual combination of distance and capacity, existing methods remain. However, a statistical assessment with metro population data shm*s the potential for RA-DSL to satisfy 4-6 times more n x DS-0 access requests than BRA, on existing copper, without carrier serving area constraints

  • Simulation study of trellis-coded transceivers for high-bit rate digital subscriber loops
    IEE Proceedings I Communications Speech and Vision, 1991
    Co-Authors: T.d. Bilodeau, W.a. Krzymien
    Abstract:

    Different transceiver structures for the proposed high-bit-rate (800 kbit/s) digital subscriber loop transmission interface are analysed. The simulation results presented in the paper demonstrate that high-bit-rate access with a considerable performance margin is feasible if baseband transceivers with appropriate equalisation and simple trellis coding are used. Initial results also indicate that more complicated bandpass transceivers with similar equalisation and trellis coding do not provide any clear performance advantage.

  • Simulation and experimental studies on the concept of a rate-adaptive digital subscriber loop (RA-DSL)
    IEEE Journal on Selected Areas in Communications, 1991
    Co-Authors: Wayne D. Grover, W.a. Krzymien, A. Shen
    Abstract:

    The authors report simulation results and prototype control protocols for a digital subscriber loop transmission system, which will find and operate at the highest common bidirectional transmission rate that is viable on a given loop while preserving a specified noise margin. A prototype implements the rate-adaptation and transmission protocols over a captive multigauge cable facility. Simulation results predict the accompanying symbol rate versus reach characteristics for a transceiver with the same structure as basic rate access (BRA) systems under RA-DSL control. Results show that 1.5 Mb/s could be delivered to loops of up to 2 km while subscribers out to 10 km could receive 80 kb/s. For a number of specialized or short-notice situations, RA-DSL could be the basis for a fast and flexible response vehicle. If RA-DSL cannot serve an individual combination of distance and capacity, existing methods remain. However, a statistical assessment with metro population data shows the potential for RA-DSL to satisfy 4-6 times more n*DS-0 access requests than BRA on existing copper, without carrier serving area constraints. >

  • Turbo-loop: a rate-adaptive digital subscriber loop (RA-DSL) for advanced ISDN access applications
    IEEE Global Telecommunications Conference 1989 and Exhibition. 'Communications Technology for the 1990s and Beyond, 2026
    Co-Authors: W.e. Grover, W.a. Krzymien, T. Fong, A. Shen, J. Dubuc
    Abstract:

    The authors report the implementation of prototype hardware and control protocols which will automatically maximize the transmission rate of individual subscriber loops. The result is a rate-adaptive digital subscriber loop (RA-DSL) technology called Turbo-loop, which makes possible new applications such as a simple form of bandwidth-on-demand and a strategy for increased utilization of existing copper, while bridging the gap to having fiber in the loop. Results predict that Turbo-loop can deliver 1.5 Mb/s up to 2 km, reaching subscribers to 10 km and 80 kb/s, and can provide a potential increase of 400% to 600% in the total utilization of existing copper access networks. The authors describe the hardware and software design of the RA-DSL prototype and report results of adaptive transmission rate experiments on actual copper loops. Also described are simulation studies which predict the ultimate performance of a fully developed design based on the Turbo-loop principle. >

J M Cioffi - One of the best experts on this subject based on the ideXlab platform.

  • reduced delay protection of dsl systems against nonstationary disturbances
    IEEE Transactions on Communications, 2004
    Co-Authors: Dimitris Toumpakaris, J M Cioffi, D Gardan
    Abstract:

    In addition to being designed to successfully cope with stationary noise, crosstalk, and intersymbol interference, digital subscriber loop (DSL) systems need to be shielded from nonstationary disturbances, such as impulse noise and RF interference. Currently, deployed DSL systems achieve protection against nonstationary interference using a combination of Reed-Solomon (RS) codes and interleaving. However, interleaving results in delay. Long delays are undesirable in high-rate systems that support interactive applications. In this study, it is shown that the interleaving delay of DSL systems can be significantly reduced by performing erasure decoding of the RS codewords at the receiver. Three different techniques for determining the erasures are proposed. Use of the techniques results in a reduction of the interleaving delay that is required to mitigate worst-case impulse noise by up to a factor of 2, which is verified by simulation. Moreover, the techniques do not require any changes at the transmitter and therefore guarantee compatibility with currently deployed systems.

  • mismatched finite complexity mmse decision feedback equalizers
    IEEE Transactions on Signal Processing, 1997
    Co-Authors: Naofal Aldhahir, J M Cioffi
    Abstract:

    Closed-form expressions that quantify the degradation in the decision-point signal-to-noise ratio of the finite-length minimum mean-square-error decision feedback equalizer (MMSE-DFE) due to channel and noise mismatch conditions are derived. The analysis is further extended to other receiver structures, namely, the MMSE-DFE with an adaptive feedforward filter, the MMSE linear equalizer, and the discrete multitone transceiver, all under a finite-complexity constraint. The limiting case of infinite-length filters is also analyzed. In addition, we present computer simulation results that compare the performance of the various receiver structures under study, assuming a particular channel and noise mismatch model for the high-bit-rate digital subscriber loop environment. Finally, several methods that can be used to mitigate the effects of mismatch are outlined.

N. Miki - One of the best experts on this subject based on the ideXlab platform.

  • Signal processor design for digital subscriber loops
    IEEE International Symposium on Circuits and Systems, 2026
    Co-Authors: N. Miki
    Abstract:

    The author proposes a digital signal processor for line-terminating circuits (LTCs) that is applicable to different digital-subscriber-loop transmission systems by merely changing the software. Since LTCs are used about 70% for adaptive filter processing, the processor should perform adaptive filtering efficiently. Therefore, a new architecture using multiply-add components is proposed. The performance of the proposed architecture is verified in experiments. >

Hassoun Fahd - One of the best experts on this subject based on the ideXlab platform.

  • Etude de l'émission électromagnétique générée par une transmission haut débit sur un réseau de type XDSL ou PLC
    HAL CCSD, 2006
    Co-Authors: Hassoun Fahd
    Abstract:

    As part of the deployment of new transmission systems based on xDSL (x digital subscriber loop) and PLC (Powerline Communication). These techniques, implemented on existing infrastructure (electric or telephone network) to transmit high speed data, and offer new services with access to information which becomes unlimited. However, the growth rates of transmission paths increasingly diverse, and using higher frequencies require severe constraints on electromagnetic compatibility. These frequencies may cause interference phenomena associated electromagnetic characteristics of the equipment deployed and used physical links. It is therefore appropriate to consider these problems of electromagnetic emission during the deployment of broadband services in order to avoid possible effects on radio systems, or between wired broadband systems occupying the same frequency bands. This thesis is part of that framework and is oriented towards the development of predictive methods to apply to transmission systems encountered in the broadband access network. This is a theory of selecting effective for determining the radiation found in the vicinity of electrical or telecommunications lines, crossed by high frequency signals. The second thrust of this work is devoted to seeking ways to reduce the electromagnetic emissions of these new servicesDans le cadre du déploiement de nouveaux systèmes de transmission basés sur les technologies xDSL (x digital subscriber loop) et PLC (PowerLine Communication). Ces techniques, mises en oeuvre sur l'infrastructure existante (réseau téléphonique ou électrique) afin de transmettre des données haut débit, et offrent de nouveaux services avec un accès à l'information qui devient illimité. Cependant, cette augmentation des débits sur des voies de transmission de plus en plus variées, et l'utilisation de fréquences élevées exigent de sévères contraintes de compatibilité électromagnétique. Ces fréquences susceptibles d'engendrer des phénomènes d'interférences électromagnétiques associés aux caractéristiques des équipements déployés et des liens physiques utilisés. Il convient donc de prendre en compte ces problèmes d'émission électromagnétique lors du déploiement des services haut débit afin d'éviter d'éventuelles conséquences sur les systèmes radioélectriques, ou entre systèmes filaires hauts débits occupant les mêmes bandes de fréquences. Ce travail de thèse s'inscrit dans ce cadre général et est orienté vers le développement de méthodes prédictives en vue de les appliquer à des systèmes de transmission haut débit rencontrés dans le réseau d'accès. Il s'agit de sélectionner une théorie efficace, permettant de déterminer le rayonnement trouvé à proximité de lignes de télécommunications ou électriques, parcourues par des signaux de hautes fréquences. Le second axe de ce travail est consacré à la recherche de méthodes permettant de diminuer les émissions électromagnétiques de ces nouveaux service

  • Etude de l'émission électromagnétique générée par une transmission haut débit sur un réseau de type XDSL ou PLC
    2006
    Co-Authors: Hassoun Fahd, Granet Gérard
    Abstract:

    Dans le cadre du déploiement de nouveaux systèmes de transmission basés sur les technologies xDSL (x digital subscriber loop) et PLC (PowerLine Communication). Ces techniques, mises en oeuvre sur l'infrastructure existante (réseau téléphonique ou électrique) afin de transmettre des données haut débit, et offrent de nouveaux services avec un accès à l'information qui devient illimité. Cependant, cette augmentation des débits sur des voies de transmission de plus en plus variées, et l'utilisation de fréquences élevées exigent de sévères contraintes de compatibilité électromagnétique. Ces fréquences susceptibles d'engendrer des phénomènes d'interférences électromagnétiques associés aux caractéristiques des équipements déployés et des liens physiques utilisés. Il convient donc de prendre en compte ces problèmes d'émission électromagnétique lors du déploiement des services haut débit afin d'éviter d'éventuelles conséquences sur les systèmes radioélectriques, ou entre systèmes filaires hauts débits occupant les mêmes bandes de fréquences. Ce travail de thèse s'inscrit dans ce cadre général et est orienté vers le développement de méthodes prédictives en vue de les appliquer à des systèmes de transmission haut débit rencontrés dans le réseau d'accès. Il s'agit de sélectionner une théorie efficace, permettant de déterminer le rayonnement trouvé à proximité de lignes de télécommunications ou électriques, parcourues par des signaux de hautes fréquences. Le second axe de ce travail est consacré à la recherche de méthodes permettant de diminuer les émissions électromagnétiques de ces nouveaux servicesCLERMONT FD-BCIU Sci.et Tech. (630142101) / SudocSudocFranceF