Patents by Inventor Klas Ericson
Klas Ericson has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9923600Abstract: The present disclosure relates to wireline communication systems, and in particular to aspects of a method and a line estimation device for estimating a characteristic impedance of a section of a transmission medium. The method comprises determining, by a test equipment having a test port with known impedance Zref, an S11 scattering parameter vector S11ref[f] of the transmission medium, indexed by frequency f. The method also comprises generating, based on Zref and S11ref[f], a model of reflection in the transmission medium corresponding to an observation of the transmission medium via a test port having a test impedance ZT, and also estimating the characteristic impedance of the section as a value of ZT which minimizes a difference between a reflection value of the model of reflection and a respective target reflection value of the section.Type: GrantFiled: June 19, 2014Date of Patent: March 20, 2018Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Antoni Fertner, Per Ola Börjesson, Klas Ericson
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Patent number: 9667464Abstract: The present disclosure relates to a Time Duplex Division (TDD) modem and a method in such a modem for making Single Ended Line Test (SELT) measurements. The device comprises a transmitter and a receiver and it has a normal mode of TDD communication. In these devices, Time Domain Reflectometry (TDR) is used as line measurement. It has a number of drawbacks, and for overcoming said drawbacks, Frequency Domain Reflectometry (FDR) measurement techniques adapted for TDD devices are suggested.Type: GrantFiled: February 14, 2012Date of Patent: May 30, 2017Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Per-Erik Eriksson, Miguel Berg, Daniel Cederholm, Klas Ericson, Chenguang Lu
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Publication number: 20170117936Abstract: The present disclosure relates to wireline communication systems, and in particular to aspects of a method and a line estimation device for estimating a characteristic impedance of a section of a transmission medium. The method comprises determining, by a test equipment having a test port with known impedance Zref, an S11 scattering parameter vector S11ref[f] of the transmission medium, indexed by frequency f. The method also comprises generating, based on Zref and S11ref[f], a model of reflection in the transmission medium corresponding to an observation of the transmission medium via a test port having a test impedance ZT, and also estimating the characteristic impedance of the section as a value of ZT which minimizes a difference between a reflection value of the model of reflection and a respective target reflection value of the section.Type: ApplicationFiled: June 19, 2014Publication date: April 27, 2017Applicant: Telefonaktiebolaget LM Ericsson (pub)Inventors: Antoni Fertner, Per Ola Börjesson, Klas Ericson
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Patent number: 9313112Abstract: A method and a test device for determining communication characteristics of a metal cable suitable for use in a communication system are provided. The method comprises transmitting a wideband test signal on the metal cable; receiving a reflected signal as a result of the wideband test signal; and determining an interval of the reflected signal to be analyzed, the interval corresponding to a part of the cable length. The method further comprises approximating the reflected signal within the interval by a regression model; and determining characteristics of the metal cable based on the regression model.Type: GrantFiled: June 27, 2013Date of Patent: April 12, 2016Assignee: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)Inventors: Antoni Fertner, Miguel Berg, Per Ola Börjesson, Daniel Cederholm, Klas Ericson
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Publication number: 20150222511Abstract: A method and a test device for determining communication characteristics of a metal cable suitable for use in a communication system are provided. The method comprises transmitting a wideband test signal on the metal cable; receiving a reflected signal as a result of the wideband test signal; and determining an interval of the reflected signal to be analysed, the interval corresponding to a part of the cable length. The method further comprises approximating the reflected signal within the interval by a regression model; and determining characteristics of the metal cable based on the regression model.Type: ApplicationFiled: June 27, 2013Publication date: August 6, 2015Inventors: Antoni Fertner, Miguel Berg, Per Ola Börjesson, Daniel Cederholm, Klas Ericson
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Patent number: 9009017Abstract: Embodiments of the present invention relate to an arrangement for analyzing transmission line properties. Measurement data providing means provide data of a first frequency dependent line property, line property calculation arrangement with model handling means, a Hubert transform handler and line property determination means calculate said first property based on model parameters, line resistance at 0 frequency, roc, a cut-off frequency, v, a line capacitance C? and a line inductance L?H. The line model handling means calculates the line inductance L(f) via a Hubert transform of a function of Q(f/v), wherein the function Q(f/v) relates the line resistance R(f) to roc as R(f)=roc·Q(f/v). The Hilbert transform values are calculated using a parameterized closed form expression for the Hubert transform or they are tabulated.Type: GrantFiled: January 8, 2010Date of Patent: April 14, 2015Assignee: Telefonaktiebolaget LM Ericsson (Publ)Inventors: Antoni Fertner, Fredrik Lindqvist, Ioanna Pappa, Klas Ericson, Miguel Berg, Per Ola Börjesson, Stefan Höst
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Publication number: 20140307763Abstract: The present disclosure relates to a Time Duplex Division (TDD) modem and a method in such a modem for making Single Ended Line Test (SELT) measurements. The device comprises a transmitter and a receiver and it has a normal mode of TDD communication. In these devices, Time Domain Reflectometry (TDR) is used as line measurement. It has a number of drawbacks, and for overcoming said drawbacks, Frequency Domain Reflectometry (FDR) measurement techniques adapted for TDD devices are suggested.Type: ApplicationFiled: February 14, 2012Publication date: October 16, 2014Applicant: Telefonaktiebolaget I.M. Ericsson (publ)Inventors: Per-Erik Eriksson, Miguel Berg, Daniel Cederholm, Klas Ericson, Chenguang Lu
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Patent number: 8798946Abstract: The present invention relates to a method and an arrangement based on two-port network (TPN) theory that allows analytically estimating the loop transfer function from open and short-circuited input impedance measurements, e.g. single ended line transmission (SELT) measurements, by utilizing the fact that the line under test (LUT) can be considered reciprocal and by assuming that the LUT is symmetric. Hence, by using the present invention and an estimation of the noise on the line, the attainable bit rate at the customer premises can be determined by means of SELT measurements at the CO. The transfer function of a telephone copper-loop is estimated regardless of its topology by impedance measurements from the CO side. Specifically, such estimation is carried out from the calculation of the transmission parameters of loop, which are expressed only in terms of open and short-circuited input impedance measurements at the CO when reciprocity and symmetry is assumed.Type: GrantFiled: August 28, 2008Date of Patent: August 5, 2014Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Klas Ericson, Roberto Menezes Rodrigues, Joäo C. Weyl Albuqerque Costa, Aldebaro Klautau
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Patent number: 8705636Abstract: The present invention relates to a method for estimating properties of a transmission line by means of features of a noise spectrum generated by noise entering said transmission line at an intermediate location between the ends of the line. The invention provides possibility to estimate a number of properties, e.g. length of a portion of the transmission line, line attenuation of said line portion and even line termination.Type: GrantFiled: October 13, 2009Date of Patent: April 22, 2014Assignee: Telefonaktiebolaget L M Ericsson (Publ)Inventors: Antoni Fertner, Miguel Berg, Per Ola Borjesson, Daniel Cederholm, Klas Ericson
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Patent number: 8681945Abstract: Method, arrangement and devices for calibration of a line driving device, such as a DSLAM, having a line port. The method comprises deriving of a first parameter vector, PVinf, for example Hinf. The parameter vector PVinf is derived by performing, at a first site, an echo measurement on the line driving device while the line port on said line driving device is open. The method further comprises calibrating the line driving device based on the first parameter vector PVinf and a second parameter vector PVref, which second parameter vector is based on information on echo measurements performed on at least one reference line driving device.Type: GrantFiled: December 22, 2011Date of Patent: March 25, 2014Assignee: Telefonaktiebolaget LM Ericsson (Publ)Inventors: Klas Ericson, Antoni Fertner, Fredrik Lindqvist, Henrik Almeida, Miguel Berg, Per Ola Borjesson
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Publication number: 20130163729Abstract: Method, arrangement and devices for calibration of a line driving device, such as a DSLAM, having a line port. The method comprises deriving of a first parameter vector, PVinf, for example Hinf. The parameter vector PVinf is derived by performing, at a first site, an echo measurement on the line driving device while the line port on said line driving device is open. The method further comprises calibrating the line driving device based on the first parameter vector PVinf and a second parameter vector PVref, which second parameter vector is based on information on echo measurements performed on at least one reference line driving device.Type: ApplicationFiled: December 22, 2011Publication date: June 27, 2013Inventors: Klas Ericson, Antoni Fertner, Fredrik Lindqvist, Henrik Almeida, Miguel Berg, Per Ola Borjesson
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Publication number: 20130158922Abstract: Method, arrangement and network node/device for estimating a quantity related to impedance in a first frequency interval, D1, of a telecommunication transmission line where the transmission line has a length d. The method involves determining a quantity related to impedance of the telecommunication transmission line for at least two frequencies, f1D2 and f2D2, in a second frequency interval D2. The frequencies f1D2 and f2D2 should fulfil the condition that the line length d times the absolute value of the difference between a line propagation constant ?(f1)D2 and a line propagation constant, ?(f2)D2, is less than ?, i.e. abs(d*?(f1)D2?d*?(f2)D2)<?. The method further involves estimating a quantity related to impedance in the first frequency interval D1 based on the determined quantity related to impedance in the second frequency interval D2, where the estimating involves the fitting of a Puiseux series to the determined quantity related to impedance in frequency interval D2.Type: ApplicationFiled: December 20, 2011Publication date: June 20, 2013Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)Inventors: Antoni Fertner, Henrik Almeida, Miguel Berg, Per Ola Börjesson, Klas Ericson, Fredrik Lindqvist
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Patent number: 8428224Abstract: The present invention concerns methods for estimating one or more transmission properties of a telecommunications transmission line. Estimates of the line input impedance, Zin at a frequency ƒ, and the line capacitance ? are made. An estimate is then made in dependence of ?, the frequency ƒ and a value ?, where ? satisfies the relationship ? coth (?)=Zin·j??, and ?=2?ƒ. Accuracy may be improved by least squares fitting a curve to a set of intermediate values and then generating an estimate from the coefficients of the curve.Type: GrantFiled: April 23, 2008Date of Patent: April 23, 2013Assignee: Telefonaktiebolaget L M Ericsson (publ)Inventors: Antoni Fertner, Per Ola Börjesson, Klas Ericson
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Patent number: 8385510Abstract: A FDR SELT measurement is made in a stop band of a DSL band plan, using a PSD allowed by the PSD mask. Further measurements may also be made in an adjacent pass band and further bands, and the results combined to create a wide-band measurement result. When transformed into the time domain (e.g. by inverse Fourier transform to produce the line impulse response) greater resolution in time (and hence greater spatial resolution) is achieved. In order to compensate for AGC calibration errors measurements using different AGC steps may be scaled to fit smoothly to each other. If measurements overlap, measurement results in the region of overlap may be combined in various ways to limit the influence of noise and to create a smooth transition from one measurement to the next.Type: GrantFiled: November 27, 2009Date of Patent: February 26, 2013Assignee: Telefonaktiebolaget L M Ericsson (publ)Inventors: Miguel Berg, Daniel Cederholm, Klas Ericson, Per Ola Börjesson
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Publication number: 20120215503Abstract: Embodiments of the present invention relate to an arrangement for analyzing transmission line properties. Measurement data providing means provide data of a first frequency dependent line property, line property calculation arrangement with model handling means, a Hubert transform handler and line property determination means calculate said first property based on model parameters, line resistance at 0 frequency, roc r cut-off frequency, v, line capacitance C?r and line inductance ??. The line model handling means calculates the line inductance L(J) via a Hubert transform of Q(f/v)r relating line resistance R(J) to roc such as formula (I). The Hilbert transform values are calculated using a parameterized closed form expression for the Hubert transform or they are tabulated.Type: ApplicationFiled: January 8, 2010Publication date: August 23, 2012Inventors: Antoni Fertner, Fredrik Lindqvist, Ioanna Pappa, Klas Ericson, Miguel Berg, Per Ola Börjesson, Stefan Höst
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Publication number: 20120069883Abstract: The present invention relates to a method for estimating properties of a transmission line by means of features of a noise spectrum generated by noise entering said transmission line at an intermediate location between the ends of the line. The invention provides possibility to estimate a number of properties, e.g. length of a portion of the transmission line, line attenuation of said Sine portion and even line termination.Type: ApplicationFiled: October 13, 2009Publication date: March 22, 2012Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)Inventors: Antoni Fertner, Miguel Berg, Per Ola Borjesson, Daniel Cederholm, Klas Ericson
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Publication number: 20110261932Abstract: A FDR SELT measurement is made in a stop band of a DSL band plan, using a PSD allowed by the PSD mask. Further measurements may also be made in an adjacent pass band and further bands, and the results combined to create a wide-band measurement result. When transformed into the time domain (e.g. by inverse Fourier transform to produce the line impulse response) greater resolution in time (and hence greater spatial resolution) is achieved. In order to compensate for AGC calibration errors measurements using different AGC steps may be scaled to fit smoothly to each other. If measurements overlap, measurement results in the region of overlap may be combined in various ways to limit the influence of noise and to create a smooth transition from one measurement to the next.Type: ApplicationFiled: November 27, 2009Publication date: October 27, 2011Applicant: Telefonaktiebolaget L M Ericsson (PUBL)Inventors: Miguel Berg, Daniel Cederholm, Klas Ericson, Per Ola Börjesson
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Publication number: 20110161027Abstract: The present invention relates to a method and an arrangement based on two-port network (TPN) theory that allows analytically estimating the loop transfer function from open and short-circuited input impedance measurements, e.g. single ended line transmission (SELT) measurements, by utilizing the fact that the line under test (LUT) can be considered reciprocal and by assuming that the LUT is symmetric. Hence, by using the present invention and an estimation of the noise on the line, the attainable bit rate at the customer premises can be determined by means of SELT measurements at the CO. The transfer function of a telephone copper-loop is estimated regardless of its topology by impedance measurements from the CO side. Specifically, such estimation is carried out from the calculation of the transmission parameters of loop, which are expressed only in terms of open and short-circuited input impedance measurements at the CO when reciprocity and symmetry is assumed.Type: ApplicationFiled: August 28, 2008Publication date: June 30, 2011Applicant: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)Inventors: Klas Ericson, Roberto Menezes Rodrigues, Joäo C. Weyl Albuqerque Costa, Aldebaro Klautau
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Publication number: 20110091019Abstract: The present invention concerns methods for estimating one or more transmission properties of a telecommunications transmission line. Estimates of the line input impedance, Zin at a frequency f, and the line capacitance ? are made. An estimate is then made in dependence of ?, the frequency f and a value ?, where ? satisfies the relationship ? coth (?)=Zin·j??, and ?=2?f. Accuracy may be improved by least squares fitting a curve to a set of intermediate values and then generating an estimate from the coefficients of the curve.Type: ApplicationFiled: April 23, 2008Publication date: April 21, 2011Inventors: Antoni Fertner, Per Ola Börjesson, Klas Ericson