Patents by Inventor Philippe Wu
Philippe Wu 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: 8884706Abstract: Embodiments of the invention include a method for use in a device having a local oscillator. The method includes performing, for the local oscillator that is disciplined by an external reference signal, while locked to the external reference signal, training at least two mathematical models of the oscillator to determine a predicted correction signal for each mathematical model based at least in part on a correction signal that is a function of the external reference signal and which is used to discipline drift in the oscillator. The method also includes selecting a mathematical model of the at least two mathematical models that results in a smallest time error when disciplining the oscillator to use when the external reference signal is unavailable and an alternative correction signal is to be used to discipline drift in the oscillator.Type: GrantFiled: March 25, 2011Date of Patent: November 11, 2014Assignee: BlackBerry LimitedInventors: Charles Nicholls, Philippe Wu
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Patent number: 8847690Abstract: Aspects of the embodiments include a method for synchronizing a device having an oscillator to a reference signal. A correction signal can be determined based on the reference signal. A mathematical model of the oscillator can be trained based at least upon the correction signal. A predicted correction signal for the trained mathematical model can be determined. A time error using the predicted correction signal can be generated to assess suitability of the trained mathematical model for disciplining drift in the oscillator and synchronizing the device when the reference signal is not available.Type: GrantFiled: September 14, 2012Date of Patent: September 30, 2014Assignee: BlackBerry LimitedInventors: Charles Nicholls, Philippe Wu
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Patent number: 8674778Abstract: A method and apparatus for correcting oscillator frequency drift due to crystal aging. Correction signals that reflect a difference between an oscillator timing signal and a reference timing signal over a reference timing signal interval are modeled so that auxiliary correction signals can be generated in the event of loss of the reference timing signal. A temperature curve is generated to model how temperature variation impacts oscillator frequency drift. A rate of frequency drift due to crystal aging is also determined. During loss of a reference timing signal, auxiliary correction signals can be generated to maintain the oscillator at a desired frequency until the reference timing signal becomes available again.Type: GrantFiled: May 9, 2008Date of Patent: March 18, 2014Assignee: Apple Inc.Inventors: Charles W. T. Nicholls, Philippe Wu
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Publication number: 20130046497Abstract: Aspects of the embodiments include a method for synchronizing a device having an oscillator to a reference signal. A correction signal can be determined based on the reference signal. A mathematical model of the oscillator can be trained based at least upon the correction signal. A predicted correction signal for the trained mathematical model can be determined. A time error using the predicted correction signal can be generated to assess suitability of the trained mathematical model for disciplining drift in the oscillator and synchronizing the device when the reference signal is not available.Type: ApplicationFiled: September 14, 2012Publication date: February 21, 2013Inventors: Charles Nicholls, Philippe Wu
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Publication number: 20110169577Abstract: Embodiments of the invention include a method for use in a device having a local oscillator. The method includes performing, for the local oscillator that is disciplined by an external reference signal, while locked to the external reference signal, training at least two mathematical models of the oscillator to determine a predicted correction signal for each mathematical model based at least in part on a correction signal that is a function of the external reference signal and which is used to discipline drift in the oscillator. The method also includes selecting a mathematical model of the at least two mathematical models that results in a smallest time error when disciplining the oscillator to use when the external reference signal is unavailable and an alternative correction signal is to be used to discipline drift in the oscillator.Type: ApplicationFiled: March 25, 2011Publication date: July 14, 2011Applicant: NORTEL NETWORKS LIMITEDInventors: CHARLES NICHOLLS, PHILIPPE WU
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Patent number: 7915962Abstract: Embodiments of the invention include a method for use in a device having a local oscillator. The method includes performing, for the local oscillator that is disciplined by an external reference signal, while locked to the external reference signal, training at least two mathematical models of the oscillator to determine a predicted correction signal for each mathematical model based at least in part on a correction signal that is a function of the external reference signal and which is used to discipline drift in the oscillator. The method also includes selecting a mathematical model of the at least two mathematical models that results in a smallest time error when disciplining the oscillator to use when the external reference signal is unavailable and an alternative correction signal is to be used to discipline drift in the oscillator.Type: GrantFiled: July 6, 2009Date of Patent: March 29, 2011Assignee: Nortel Networks LimitedInventors: Charles Nicholls, Philippe Wu
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Publication number: 20110001567Abstract: Embodiments of the invention include a method for use in a device having a local oscillator. The method includes performing, for the local oscillator that is disciplined by an external reference signal, while locked to the external reference signal, training at least two mathematical models of the oscillator to determine a predicted correction signal for each mathematical model based at least in part on a correction signal that is a function of the external reference signal and which is used to discipline drift in the oscillator. The method also includes selecting a mathematical model of the at least two mathematical models that results in a smallest time error when disciplining the oscillator to use when the external reference signal is unavailable and an alternative correction signal is to be used to discipline drift in the oscillator.Type: ApplicationFiled: July 6, 2009Publication date: January 6, 2011Applicant: NORTEL NETWORKS LIMITEDInventors: CHARLES NICHOLLS, PHILIPPE WU
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Publication number: 20090278616Abstract: A method and apparatus for correcting oscillator frequency drift due to crystal aging. Correction signals that reflect a difference between an oscillator timing signal and a reference timing signal over a reference timing signal interval are modeled so that auxiliary correction signals can be generated in the event of loss of the reference timing signal. A temperature curve is generated to model how temperature variation impacts oscillator frequency drift. A rate of frequency drift due to crystal aging is also determined. During loss of a reference timing signal, auxiliary correction signals can be generated to maintain the oscillator at a desired frequency until the reference timing signal becomes available again.Type: ApplicationFiled: May 9, 2008Publication date: November 12, 2009Applicant: NORTEL NETWORKS LIMITEDInventors: Charles W. T. Nicholls, Philippe Wu
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Patent number: 7015762Abstract: A reference timing signal apparatus with a phase-locked loop (PLL) has a computer algorithm which adaptively models the multiple frequencies of an oscillator following a training period. The oscillator is part of a PLL and the oscillation frequency thereof is controlled in response to the phase detector output. The computer algorithm processes the control signal applied to the oscillator. The computer algorithm updates the characteristics of the model relating to the aging and temperature of the oscillator, using for example, a Kalman filter as an adaptive filter, in accordance with a cumulative phase error in the PLL calculated during a given time interval. By the algorithm, the subsequent model predicts the future frequency state of the oscillator on which it was trained. The predicted frequency of the model functions as a reference to correct the frequency of the oscillator in the event that no input reference timing signal is available.Type: GrantFiled: August 19, 2004Date of Patent: March 21, 2006Assignee: Nortel Networks LimitedInventors: Charles Nicholls, Philippe Wu, Gregory Carleton, Steve Beaudin
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Patent number: 6711230Abstract: An input reference timing signal oscillator of a phase-locked loop has a computer algorithm which adaptively models the multiple frequencies of an oscillator following a training period. The oscillator is part of a phase-locked loop and the oscillation frequency thereof is controlled in response to the phase detector output. The computer algorithm processes the control signal applied to the oscillator. The computer algorithm updates the characteristics of the model relating to the aging and temperature of the oscillator, using for example, a Kalman filter as an adaptive filter. By the algorithm, the subsequent model predicts the future frequency state of the oscillator on which it was trained. The predicted frequency of the model functions as a reference to correct the frequency of the oscillator in the event that no input reference timing signal is available. With the model updating algorithm, oscillators of low stability performance may be used as cellular base station reference oscillator.Type: GrantFiled: September 27, 2002Date of Patent: March 23, 2004Assignee: Nortel Networks LimitedInventors: Charles Nicholls, Gregory Carleton, Philippe Wu, Yu Yang, Eric Gagnon
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Patent number: 6661895Abstract: A zero-delay structure to be used in sub-band echo cancellation systems. In telecommunications, a delay is usually introduced in sub-band decomposition and/or sub-band reconstruction. This invention will help remove this. This structure not only removes the delay but does not sacrifice the performance of the echo canceller. It is to be used in combination with any sub-band-based echo canceller or wavelet echo canceller.Type: GrantFiled: October 7, 1999Date of Patent: December 9, 2003Assignee: Zarlink Semiconductor Inc.Inventors: Qu Jin, Kon Max Wong, Qiang Wu, Philippe Wu, Gordon J. Reesor