Patrick Boets - Academia.edu (original) (raw)

Papers by Patrick Boets

A survey of frequency domain models to describe cables of the access network of operators is pres... more A survey of frequency domain models to describe cables of the access network of operators is presented. The cable characteristics of some commercial cables are measured and the parameters of the used mod- els identifled. From this, the properties and application areas of physical models as well as rational functions are discussed. It will be demonstrated and explained why some

A measurement, modelling and identification system is proposed to qualify a subscriber line with ... more A measurement, modelling and identification system is proposed to qualify a subscriber line with the constraint that only measurements can be conducted at the Central Office. The system uses the one-port scattering parame- ter as a base measurement of the loop. The time domain version of this scattering parameter will be pre-processed so that the features, which are the start,

IMTC 2001. Proceedings of the 18th IEEE Instrumentation and Measurement Technology Conference. Rediscovering Measurement in the Age of Informatics (Cat. No.01CH 37188), 2000

A new physical model 'VUB1' is proposed to characterize a metallic parallel wire or twisted wire ... more A new physical model 'VUB1' is proposed to characterize a metallic parallel wire or twisted wire pair. The VUB1 model will be compared with a rational function in the sdomain and with the popular physical model 'BT0' of British Telecom as described in the standards for Metallic Acces Networks. The VUB model contains a limited parameter set and is linear and time invariant there were the models used in the standards use more parameters and are semi-empirical, which can lead to non-causal systems. Metallic cable characterization with physical models will be compared with rational functions in the Laplace-domain. A Maximum Likelihood Estimation framework is used in the frequency domain to identify the model parameters. The performance of the models will be compared with a simulation directly based on measurements.

A model for the crosstalk between two twisted pairs caused by splices, is proposed. The model wil... more A model for the crosstalk between two twisted pairs caused by splices, is proposed. The model will allow the crosstalk to be calculated in any case where splices exist in a transmission line. The expressions are then evaluated by measurements on a lab-produced splice and the total influence of the splices on the total crosstalk is evaluated, in order to

In this paper, an efficient and area optimized infinite impulse response (IIR) filter realization... more In this paper, an efficient and area optimized infinite impulse response (IIR) filter realization in field programmable gate arrays is proposed. The realized IIR filter emulates the frequency dependent magnitude and phase characteristic of a transmission line or data transmission cable of variable length. Because of the real time nature of the emulation (determined by the physical propagation delay of the cable), processing time is strictly limited. The optimal and efficient realization described uses a cascade of second order IIR filters with large word size. The sample rate exceeds 10 MSPS, using serial-digit arithmetic in field programmable gate arrays (FPGA -Xilinx SpartanII XC2S200).

The Expert System, which is described in this paper, constitutes a fundamental unit of a general ... more The Expert System, which is described in this paper, constitutes a fundamental unit of a general measurement system, which is capable to perform an xDSL (arbitrary Digital Subscriber Line) loop qualification by means of time-domain reflectometry (TDR).

The lift-off of DSL (digital subscriber line) has urged the subscriber line testing equipment man... more The lift-off of DSL (digital subscriber line) has urged the subscriber line testing equipment manufacturers to extend their narrowband POTS (plain old telephony service) testheads towards DSL. The local loop, which connects the customer premises (CP) to the central office (CO) and which has been designed for POTS voice-band transmission, may have numerous impairments with respect to DSL. Some impairments, such as load coils, have to be detected, located, and removed. Others, such as bridged taps, don't have to be removed, but can seriously impact the maximum achievable loop bit rate. The dream of every telecom operator is a testhead that can accurately estimate the loop channel capacity expressed in bit/s by means of single-ended measurements only. In this paper we will give an overview of local loop impairments and subscriber line testing methods, focussing on metallic line testing and especially time-domain reflectometry (TDR). The authors have developed a reflectometric loop ...

Proceedings of the 20th IEEE Instrumentation Technology Conference (Cat. No.03CH37412), 2003

A measurement set-up is proposed to measure the oneport scattering parameter of a subscriber line... more A measurement set-up is proposed to measure the oneport scattering parameter of a subscriber line at the Central Office. The measurements are performed in the time domain using periodic multi-sine signals. A pre-processing algorithm will deliver the impulse response of the one-port scattering parameter. It will de-noise and de-alias the impulse response and search for the first significant reflection. It will be shown that the processed impulse response of the one-port scattering parameter reveals the most important signal features, which would otherwise remain undetectable using classic time domain reflectometry. J J J J a J J a J J a J J a J J J J

Conference Proceedings. 10th Anniversary. IMTC/94. Advanced Technologies in I & M. 1994 IEEE Instrumentation and Measurement Technolgy Conference (Cat. No.94CH3424-9), 1994

A survey of frequency domain models to describe cables of the access network of operators is pres... more A survey of frequency domain models to describe cables of the access network of operators is presented. The cable characteristics of some commercial cables are measured and the parameters of the used mod- els identifled. From this, the properties and application areas of physical models as well as rational functions are discussed. It will be demonstrated and explained why some

A measurement, modelling and identification system is proposed to qualify a subscriber line with ... more A measurement, modelling and identification system is proposed to qualify a subscriber line with the constraint that only measurements can be conducted at the Central Office. The system uses the one-port scattering parame- ter as a base measurement of the loop. The time domain version of this scattering parameter will be pre-processed so that the features, which are the start,

IMTC 2001. Proceedings of the 18th IEEE Instrumentation and Measurement Technology Conference. Rediscovering Measurement in the Age of Informatics (Cat. No.01CH 37188), 2000

A new physical model 'VUB1' is proposed to characterize a metallic parallel wire or twisted wire ... more A new physical model 'VUB1' is proposed to characterize a metallic parallel wire or twisted wire pair. The VUB1 model will be compared with a rational function in the sdomain and with the popular physical model 'BT0' of British Telecom as described in the standards for Metallic Acces Networks. The VUB model contains a limited parameter set and is linear and time invariant there were the models used in the standards use more parameters and are semi-empirical, which can lead to non-causal systems. Metallic cable characterization with physical models will be compared with rational functions in the Laplace-domain. A Maximum Likelihood Estimation framework is used in the frequency domain to identify the model parameters. The performance of the models will be compared with a simulation directly based on measurements.

A model for the crosstalk between two twisted pairs caused by splices, is proposed. The model wil... more A model for the crosstalk between two twisted pairs caused by splices, is proposed. The model will allow the crosstalk to be calculated in any case where splices exist in a transmission line. The expressions are then evaluated by measurements on a lab-produced splice and the total influence of the splices on the total crosstalk is evaluated, in order to

In this paper, an efficient and area optimized infinite impulse response (IIR) filter realization... more In this paper, an efficient and area optimized infinite impulse response (IIR) filter realization in field programmable gate arrays is proposed. The realized IIR filter emulates the frequency dependent magnitude and phase characteristic of a transmission line or data transmission cable of variable length. Because of the real time nature of the emulation (determined by the physical propagation delay of the cable), processing time is strictly limited. The optimal and efficient realization described uses a cascade of second order IIR filters with large word size. The sample rate exceeds 10 MSPS, using serial-digit arithmetic in field programmable gate arrays (FPGA -Xilinx SpartanII XC2S200).

The Expert System, which is described in this paper, constitutes a fundamental unit of a general ... more The Expert System, which is described in this paper, constitutes a fundamental unit of a general measurement system, which is capable to perform an xDSL (arbitrary Digital Subscriber Line) loop qualification by means of time-domain reflectometry (TDR).

The lift-off of DSL (digital subscriber line) has urged the subscriber line testing equipment man... more The lift-off of DSL (digital subscriber line) has urged the subscriber line testing equipment manufacturers to extend their narrowband POTS (plain old telephony service) testheads towards DSL. The local loop, which connects the customer premises (CP) to the central office (CO) and which has been designed for POTS voice-band transmission, may have numerous impairments with respect to DSL. Some impairments, such as load coils, have to be detected, located, and removed. Others, such as bridged taps, don't have to be removed, but can seriously impact the maximum achievable loop bit rate. The dream of every telecom operator is a testhead that can accurately estimate the loop channel capacity expressed in bit/s by means of single-ended measurements only. In this paper we will give an overview of local loop impairments and subscriber line testing methods, focussing on metallic line testing and especially time-domain reflectometry (TDR). The authors have developed a reflectometric loop ...

Proceedings of the 20th IEEE Instrumentation Technology Conference (Cat. No.03CH37412), 2003

A measurement set-up is proposed to measure the oneport scattering parameter of a subscriber line... more A measurement set-up is proposed to measure the oneport scattering parameter of a subscriber line at the Central Office. The measurements are performed in the time domain using periodic multi-sine signals. A pre-processing algorithm will deliver the impulse response of the one-port scattering parameter. It will de-noise and de-alias the impulse response and search for the first significant reflection. It will be shown that the processed impulse response of the one-port scattering parameter reveals the most important signal features, which would otherwise remain undetectable using classic time domain reflectometry. J J J J a J J a J J a J J a J J J J

Conference Proceedings. 10th Anniversary. IMTC/94. Advanced Technologies in I & M. 1994 IEEE Instrumentation and Measurement Technolgy Conference (Cat. No.94CH3424-9), 1994