Patents by Inventor Derek J. W. Ho
Derek J. W. Ho 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).
-
Patent number: 9229433Abstract: Provided is a method and apparatus for aligning a first local oscillator (LO) clock generated by a controllable LO clock generator in a first radio frequency (RF) path with a second LO clock in a second RF path. The apparatus includes a synchronization channel configured to exchange a synchronization clock between the first and second RF paths, a phase detector configured to measure a phase alignment between the first and second LO clocks, and a loop filter configured to drive the controllable LO clock generators using the phase alignment. Also provided is a time to digital converter. The time to digital converter includes a D flip-flop for sampling first and second input clocks with a third clock, and a counter configured to synchronously increment the resulting samples and create a digital proportional value representing the delay between the first and second clocks.Type: GrantFiled: November 24, 2014Date of Patent: January 5, 2016Assignee: PMC-SIERRA US, INC.Inventors: Mark Hiebert, Derek J. W. Ho
-
Patent number: 8989250Abstract: Methods and circuits for equalizing a linear response in an observation path of a digital pre-distorter. A method comprises generating observed signals in an observation path based on observing a transmit signal; down-converting the observed signals into intermediate frequencies using different LO frequencies; calculating a ratio using the intermediate frequencies; and equalizing the linear response of the observation path on the observed signals using the ratio. An apparatus comprises a directional coupler for observing a transmit signal and generating observed signals; a down-converter for converting the observed signals into intermediate frequencies using different LO frequencies; and an adaptive estimator for calculating a ratio using the intermediate frequencies and using the ratio to equalize a linear response from the observation path on the observed signals.Type: GrantFiled: March 15, 2013Date of Patent: March 24, 2015Assignee: PMC-Sierra US, Inc.Inventors: William D. Warner, Andrew S. Wright, Bartholomeus T. W. Klijsen, Derek J. W. Ho
-
Patent number: 7904033Abstract: The invention is related to methods and apparatus for controlling and adapting a digital predistortion linearizer for amplification of bandlimited signals using non-linear amplifiers. The control method advantageously permits the predistortion function applied by a predistortion entity to provide a relatively constant gain. This attribute is advantageous for operation within cellular radio systems, which often employ digital power control systems. However, the disclosed techniques can also be applicable to virtually any type of digital predistortion for which an input signal or reference signal to be amplified is predistorted in a manner that is complementary to the distortion induced by a non-linear amplifier. Embodiments of the invention advantageously enhance the practicality of using digital linearization and predistortion amplification techniques.Type: GrantFiled: February 26, 2007Date of Patent: March 8, 2011Assignee: PMC-Sierra, Inc.Inventors: Andrew S. Wright, Derek J. W. Ho, Bartholomeus T. W. Klijsen
-
Patent number: 7340223Abstract: The invention is related to methods and apparatus for controlling and adapting a digital predistortion linearizer for amplification of bandlimited signals using non-linear amplifiers. The control method advantageously permits the predistortion function applied by a predistortion entity to provide a relatively constant gain. This attribute is advantageous for operation within cellular radio systems, which often employ digital power control systems. However, the disclosed techniques can also be applicable to virtually any type of digital predistortion for which an input signal or reference signal to be amplified is predistorted in a manner that is complementary to the distortion induced by a non-linear amplifier. Embodiments of the invention advantageously enhance the practicality of using digital linearization and predistortion amplification techniques.Type: GrantFiled: March 29, 2006Date of Patent: March 4, 2008Assignee: PMC-Sierra, Inc.Inventors: Andrew S. Wright, Derek J. W. Ho, Bartholomeus T. W. Klijsen
-
Patent number: 7295815Abstract: The invention is related to methods and apparatus for controlling and adapting a digital predistortion linearizer for amplification of bandlimited signals using non-linear amplifiers. The control method advantageously permits the predistortion function applied by a predistortion entity to provide a relatively constant gain. This attribute is advantageous for operation within cellular radio systems, which often employ digital power control systems. However, the disclosed techniques can also be applicable to virtually any type of digital predistortion for which an input signal or reference signal to be amplified is predistorted in a manner that is complementary to the distortion induced by a non-linear amplifier. Embodiments of the invention advantageously enhance the practicality of using digital linearization and predistortion amplification techniques.Type: GrantFiled: March 29, 2006Date of Patent: November 13, 2007Assignee: PMC-Sierra, Inc.Inventors: Andrew S. Wright, Derek J. W. Ho, Bartholomeus T. W. Klijsen
-
Patent number: 7260365Abstract: The invention is related to methods and apparatus for controlling and adapting a digital predistortion linearizer for amplification of bandlimited signals using non-linear amplifiers. The control method advantageously permits the predistortion function applied by a predistortion entity to provide a relatively constant gain. This attribute is advantageous for operation within cellular radio systems, which often employ digital power control systems. However, the disclosed techniques can also be applicable to virtually any type of digital predistortion for which an input signal or reference signal to be amplified is predistorted in a manner that is complementary to the distortion induced by a non-linear amplifier. Embodiments of the invention advantageously enhance the practicality of using digital linearization and predistortion amplification techniques.Type: GrantFiled: March 29, 2006Date of Patent: August 21, 2007Assignee: PMC-Sierra, Inc.Inventors: Andrew S. Wright, Derek J. W. Ho, Bartholomeus T. W. Klijsen
-
Patent number: 7200367Abstract: The invention is related to methods and apparatus for controlling and adapting a digital predistortion linearizer for amplification of bandlimited signals using non-linear amplifiers. The control method advantageously permits the predistortion function applied by a predistortion entity to provide a relatively constant gain. This attribute is advantageous for operation within cellular radio systems, which often employ digital power control systems. However, the disclosed techniques can also be applicable to virtually any type of digital predistortion for which an input signal or reference signal to be amplified is predistorted in a manner that is complementary to the distortion induced by a non-linear amplifier. Embodiments of the invention advantageously enhance the practicality of using digital linearization and predistortion amplification techniques.Type: GrantFiled: March 29, 2006Date of Patent: April 3, 2007Assignee: PMC-Sierra, Inc.Inventors: Andrew S. Wright, Derek J. W. Ho, Bartholomeus T. W. Klijsen
-
Patent number: 7177603Abstract: The invention is related to methods and apparatus for controlling and adapting a digital predistortion linearizer for amplification of bandlimited signals using non-linear amplifiers. The control method advantageously permits the predistortion function applied by a predistortion entity to provide a relatively constant gain. This attribute is advantageous for operation within cellular radio systems, which often employ digital power control systems. However, the disclosed techniques can also be applicable to virtually any type of digital predistortion for which an input signal or reference signal to be amplified is predistorted in a manner that is complementary to the distortion induced by a non-linear amplifier. Embodiments of the invention advantageously enhance the practicality of using digital linearization and predistortion amplification techniques.Type: GrantFiled: March 29, 2006Date of Patent: February 13, 2007Assignee: PMC-Sierra, Inc.Inventors: Andrew S. Wright, Derek J. W. Ho, Bartholomeus T. W. Klijsen
-
Patent number: 7058369Abstract: The invention is related to methods and apparatus for controlling and adapting a digital predistortion linearizer for amplification of bandlimited signals using non-linear amplifiers. The control method advantageously permits the predistortion function applied by a predistortion entity to provide a relatively constant gain. This attribute is advantageous for operation within cellular radio systems, which often employ digital power control systems. However, the disclosed techniques can also be applicable to virtually any type of digital predistortion for which an input signal or reference signal to be amplified is predistorted in a manner that is complementary to the distortion induced by a non-linear amplifier. Embodiments of the invention advantageously enhance the practicality of using digital linearization and predistortion amplification techniques.Type: GrantFiled: November 21, 2002Date of Patent: June 6, 2006Assignee: PMC-Sierra Inc.Inventors: Andrew S. Wright, Derek J. W. Ho, Bartholomeus T. W. Klijsen