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... 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
Research Interests:
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... 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,
Research Interests:
Research Interests:
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... 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
Research Interests:
Research Interests:
Research Interests:
ABSTRACT
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Fault recognition on branched and meshed electrical transmission line networks can be simplified by comparing the measured digital reflectogram with a simulated one. The synthetic reflectogram is built up in the frequency domain, making... more
Fault recognition on branched and meshed electrical transmission line networks can be simplified by comparing the measured digital reflectogram with a simulated one. The synthetic reflectogram is built up in the frequency domain, making use of models that describe attenuation and dispersion of a pulse propagating on a uniform transmission line. A new method to accurately model any line type in the frequency domain is considered. It is shown how the parameters of this model can be determined from noisy time-domain-reflectometer (TDR) measurements. An example application involving the RG58C/U coaxial cable shows the use of simulation in prefault detection
Research Interests:
ABSTRACT
Research Interests:
Abstract This contribution proposes a new family of methods to reduce the peak-to-average power ratio (PAR) in discrete multi-tone (DMT) and orthogonal frequency division multiplexing (OFDM) systems. This method avoids the use of extra... more
Abstract This contribution proposes a new family of methods to reduce the peak-to-average power ratio (PAR) in discrete multi-tone (DMT) and orthogonal frequency division multiplexing (OFDM) systems. This method avoids the use of extra inverse fast Fourier ...
Research Interests:
Research Interests:
Abstract-In this paper, it is shown how the downstream en upstream capacity of a VDSL connection will be affected if the in-home splitter is not installed according to the client installation instructions. The established data rate will... more
Abstract-In this paper, it is shown how the downstream en upstream capacity of a VDSL connection will be affected if the in-home splitter is not installed according to the client installation instructions. The established data rate will be investigated for several real-life in-home cabling topologies.
A new crosstalk model between two twisted pairs when a mismatch of the wire pairs extremities exist, is proposed. The crosstalk model allows to predict the PSD at the near-end and far-end of the victim line if the PSD of the disturber is... more
A new crosstalk model between two twisted pairs when a mismatch of the wire pairs extremities exist, is proposed. The crosstalk model allows to predict the PSD at the near-end and far-end of the victim line if the PSD of the disturber is known. The model takes any mismatch into account which exists when a line is not terminated with its characteristic impedance. Using the same unbalance assumptions as other authors used with success in the past, analytical expressions are given to calculate the crosstalk.
Research Interests:
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... 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).
Research Interests:
One of the most challenging problems related to single- ended line testing (SELT) is the estimation of the noise power spectral density (PSD) at the customer-premises (CP) side of the line under test, because only measurements at the... more
One of the most challenging problems related to single- ended line testing (SELT) is the estimation of the noise power spectral density (PSD) at the customer-premises (CP) side of the line under test, because only measurements at the central-office side (CO) are possible. A solution for the noise caused by crosstalk could consist of first identifying the disturbers present in the cable binder of the line under test based on the measured noise PSD at the CO side and secondly estimating the noise PSD at the CP side by means of crosstalk models and the transmit PSD's of the identified disturbers. In this paper we focus on the first part of the solution, the disturber identification. For the identification non-parametric and parametric modeling approaches are explored. The estimator is based on a maximum-likelihood (ML) cost function. The proposed algorithms have been experimentally verified by means of measurements on a France Telecom cable.