Roberto Rodrigues - Academia.edu (original) (raw)
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Papers by Roberto Rodrigues
2011 IEEE EUROCON - International Conference on Computer as a Tool, 2011
A method to identify some physical parameters of twisted-pair cables is presented in this paper. ... more A method to identify some physical parameters of twisted-pair cables is presented in this paper. The parameters identification process is carried out from input impedance measurements, applying analytical approach and mean squared estimation. The obtained results indicate the accuracy and applicability of the proposed method. Index Terms—System identification, transmission line theory, twisted-pair cable, digital subscriber line.
IEEE Transactions on Instrumentation and Measurement, 2000
The ability of a specific telephone line to support a certain digital subscriber line (DSL) servi... more The ability of a specific telephone line to support a certain digital subscriber line (DSL) service is determined by its downstream and upstream data rates, which are mainly dependent on the line's transfer function. In this way, methods for transfer function estimation play an important role on proper DSL deployment. Most of the existing methods derive the transfer function via line topology identification (LTI) processes. This paper proposes a method which directly estimates the transfer function of telephone lines without any previous LTI process. The results obtained from both simulations and experimental procedure using twisted-pair cables indicate that the proposed method achieves accurate estimations even for lines with bridged-taps.
IEEE Transactions on Instrumentation and Measurement, 2000
The broadband capacity of the twisted-pair lines strongly varies within the copper access network... more The broadband capacity of the twisted-pair lines strongly varies within the copper access network. It is therefore important to assess the ability of a digital subscriber line (DSL) to support the DSL services prior to deployment. This task is handled by the line qualification procedures, where the identification of the line topology is an important part. This paper presents a new method, denoted topology identification via model-based evolutionary computation (TIMEC), for line topology identification, where either one-port measurements or both one-and two-port measurements are utilized. The measurements are input to a model-based multiobjective criterion that is minimized by a genetic algorithm to provide an estimate of the line topology. The inherent flexibility of TIMEC enables the incorporation of a priori information, e.g., the total line length. The performance of TIMEC is evaluated by computer simulations with varying degrees of information. Comparison with a state-of-art method indicates that TIMEC achieves better results for all the tested lines when only one-port measurements are used. The results are improved when employing both one-and two-port measurements. If a rough estimate of the total length is also used, near-perfect estimation is obtained for all the tested lines.
2011 IEEE EUROCON - International Conference on Computer as a Tool, 2011
A method to identify some physical parameters of twisted-pair cables is presented in this paper. ... more A method to identify some physical parameters of twisted-pair cables is presented in this paper. The parameters identification process is carried out from input impedance measurements, applying analytical approach and mean squared estimation. The obtained results indicate the accuracy and applicability of the proposed method. Index Terms—System identification, transmission line theory, twisted-pair cable, digital subscriber line.
IEEE Transactions on Instrumentation and Measurement, 2000
The ability of a specific telephone line to support a certain digital subscriber line (DSL) servi... more The ability of a specific telephone line to support a certain digital subscriber line (DSL) service is determined by its downstream and upstream data rates, which are mainly dependent on the line's transfer function. In this way, methods for transfer function estimation play an important role on proper DSL deployment. Most of the existing methods derive the transfer function via line topology identification (LTI) processes. This paper proposes a method which directly estimates the transfer function of telephone lines without any previous LTI process. The results obtained from both simulations and experimental procedure using twisted-pair cables indicate that the proposed method achieves accurate estimations even for lines with bridged-taps.
IEEE Transactions on Instrumentation and Measurement, 2000
The broadband capacity of the twisted-pair lines strongly varies within the copper access network... more The broadband capacity of the twisted-pair lines strongly varies within the copper access network. It is therefore important to assess the ability of a digital subscriber line (DSL) to support the DSL services prior to deployment. This task is handled by the line qualification procedures, where the identification of the line topology is an important part. This paper presents a new method, denoted topology identification via model-based evolutionary computation (TIMEC), for line topology identification, where either one-port measurements or both one-and two-port measurements are utilized. The measurements are input to a model-based multiobjective criterion that is minimized by a genetic algorithm to provide an estimate of the line topology. The inherent flexibility of TIMEC enables the incorporation of a priori information, e.g., the total line length. The performance of TIMEC is evaluated by computer simulations with varying degrees of information. Comparison with a state-of-art method indicates that TIMEC achieves better results for all the tested lines when only one-port measurements are used. The results are improved when employing both one-and two-port measurements. If a rough estimate of the total length is also used, near-perfect estimation is obtained for all the tested lines.