Patents by Inventor Syang-Myau Hwang
Syang-Myau Hwang 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: 8194793Abstract: A multi-stage frequency offset (FO) estimation and compensation method and its circuit are described. The method includes performing at least a stage of primary-level FO estimation and compensation procedure, and a stage of advance-level FO estimation and compensation procedure. The first stage receives an input carrier signal of a larger FO and outputs a corrected carrier signal with an estimation error within the required estimation range of the next stage, to the next stage. Generated and fed forward stage-by-stage, the corrected carrier signal free of FO may be approached. Besides, since a feed-forward rather than a closed-loop approach is employed, the SNR requirement may be lower. Also, at primary-level, modulation may be first removed so the whole input carrier signal may be used to estimate FO; at advance-level, the periodic PN sequence in the input carrier signal may be utilized to estimate FO, thereby no dedicated training symbols are required.Type: GrantFiled: February 1, 2010Date of Patent: June 5, 2012Assignee: Uniband Electronic Corp.Inventors: Syang-Myau Hwang, Chun Chin Chen
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Publication number: 20110080978Abstract: A multi-stage frequency offset (FO) estimation and compensation method and its circuit are described. The method includes performing at least a stage of primary-level FO estimation and compensation procedure, and a stage of advance-level FO estimation and compensation procedure. The first stage receives an input carrier signal of a larger FO and outputs a corrected carrier signal with an estimation error within the required estimation range of the next stage, to the next stage. Generated and fed forward stage-by-stage, the corrected carrier signal free of FO may be approached. Besides, since a feed-forward rather than a closed-loop approach is employed, the SNR requirement may be lower. Also, at primary-level, modulation may be first removed so the whole input carrier signal may be used to estimate FO; at advance-level, the periodic PN sequence in the input carrier signal may be utilized to estimate FO, thereby no dedicated training symbols are required.Type: ApplicationFiled: February 1, 2010Publication date: April 7, 2011Inventors: Syang-Myau HWANG, Chun Chin Chen
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Publication number: 20100080277Abstract: A method used in a time domain equalizer is provided. A method comprising the steps of: providing a time domain equalizer comprising a feed forward equalizer and a feedback equalizer; and using a conjugate gradient iteration in order to calculate a set of coefficients of the time domain equalizer.Type: ApplicationFiled: September 28, 2008Publication date: April 1, 2010Applicant: LEGEND SILICON CORP.Inventors: Lin Yang, Syang-Myau Hwang, Qian Zhuang, Jun Lu, Shue-Lee Chang
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Publication number: 20100080280Abstract: In a receiver of a multi-leveled variable sideband communications system, a method is provided that comprises the steps of: dividing the receiver into a real portion and a complex portion; and providing a decision feedback equalizer (DFE) processing data substantially in the real portion.Type: ApplicationFiled: September 28, 2008Publication date: April 1, 2010Applicant: LEGEND SILICON CORP.Inventors: Syang-Myau Hwang, Lin Yang, Shue-Lee Chang, Jun Lu
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Publication number: 20100080275Abstract: A method for training of a non-updated decision feedback equalizer is provided. The method comprising the steps of: providing a sequence of frames adapted to be received by a receiver; provide a sequence of synchronization frames interposed between a predetermined number of frames; and using at least part of the sequence of synchronization frames to train a decision feedback equalizer (DFE), thereby speeding up system convergence or making system convergence possible.Type: ApplicationFiled: September 28, 2008Publication date: April 1, 2010Applicant: LEGEND SILICON CORP.Inventors: Lin Yang, Jun Lu, Shue-Lee Chang, Jing Li, Syang-Myau Hwang
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Publication number: 20100080281Abstract: A method used in a time domain equalizer is provided. The method comprising the steps of: providing a time domain equalizer comprising; and extracting a real part of an input or a derivative of the input to the time domain equalizer and using the only real part of the input in the time domain equalizer to derive an output of the time domain equalizer.Type: ApplicationFiled: September 28, 2008Publication date: April 1, 2010Applicant: LEGEND SILICON CORP.Inventors: Syang-Myau Hwang, Lin Yang, Jing Li, Chen Liu, Jun Lu, Shue-Lee Chang
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Publication number: 20100080276Abstract: A method comprising the steps of providing a slicer for slicing real values of an equalizer output; and cross correlating an equalizer input with an output of the slicer is provided.Type: ApplicationFiled: September 28, 2008Publication date: April 1, 2010Applicant: LEGEND SILICON CORP.Inventors: Syang-Myau Hwang, Lin Yang, Jun Lu, Shue-Lee Chang
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Publication number: 20100080278Abstract: A method used in a time domain equalizer is provided. A method comprising the steps of: providing a time domain equalizer comprising a feed forward equalizer and a feedback equalizer; and using a filter circuit or structured implementation to incorporate conjugate gradient iteration in order to calculate a set of coefficients of the time domain equalizer. Whereby matrix times vector operations is converted into filtering using the filter circuit.Type: ApplicationFiled: September 28, 2008Publication date: April 1, 2010Applicant: LEGEND SILICON CORP.Inventors: Shue-Lee Chang, Lin Yang, Syang-Myau Hwang, Qian Zhuang, Chen Liu, Jun Lu, Jing Li
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Publication number: 20100082720Abstract: A method comprising the steps of: providing a known sequence comprising a plurality of data points; and curve-fitting the plurality of data points to calculate coarse frequency offset.Type: ApplicationFiled: September 28, 2008Publication date: April 1, 2010Applicant: LEGEND SILICON CORP.Inventors: Shue-Lee Chang, Jun Lu, Syang-Myau Hwang, Lin Yang
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Publication number: 20100027614Abstract: A DTV receiver having method using elastic decoding method is provided. The method comprises the steps of: receiving a signal for processing; decoding the signal using a source decoder; determining a portion of the signal that are problematic; and using elastic decoding to remedy the portion of the signal that are problematic.Type: ApplicationFiled: August 4, 2008Publication date: February 4, 2010Applicant: LEGEND SILICON CORP.Inventors: YANBIN YU, LIN YANG, YAN ZHONG, SYANG-MYAU HWANG
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Publication number: 20090135935Abstract: A receiver is provided that comprises: a channel estimator; a first path for feeding the estimated information into a frequency domain equalizer; a second path for feeding the estimated information into a time domain equalizer; and a combiner or selector to combine or select equalized information from the frequency domain equalizer and the time domain equalizer.Type: ApplicationFiled: November 28, 2007Publication date: May 28, 2009Applicant: LEGEND SILICON CORPInventors: LIN YANG, SYANG-MYAU HWANG
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Patent number: 7424047Abstract: A spread spectrum receiver whose de-spreading process based on transformed spreading codes is provided. Instead of de-spreading with original spreading codes, this approach de-spreads received signal with the spreading codes transformed from the original codes in order to eliminate the negative impact of system impairments such as frequency offset to a spread spectrum receiver. Before de-spreading with the transformed code, the received signal goes through the same transformation as the original codes do. After a transformation, the transformed codes may exist some undesirable property such as spreading code having DC content. An approach is given to cancel unwanted side effects relating the transformed spreading codes. The approaches are very effective for spread spectrum system based on frequency modulation scheme such as MSK.Type: GrantFiled: November 13, 2003Date of Patent: September 9, 2008Assignee: Uniband Electronic Corp.Inventors: Yiping Fan, Syang-Myau Hwang, Hongyu Li, Chieh-Yuan Chao
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Chip-to-symbol receiver despreader architectures and methods for despreading spread spectrum signals
Patent number: 7366227Abstract: In a spread spectrum system, methods and despreader architectures for despreading the received spreaded codes with the use of a single correlator and a single correlation code is provided. Before despreading the incoming received spreaded codes, a single correlation code is generated using a symbol from a set of symbols that has been mapped into a set of differential encoded PN codes. Despreading output samples for each received spreaded code are obtained by correlating the received spreaded code with this single correlation code. Correlation is accomplished by multiplying each received sample of the received spreaded codes with the correlation code samples and accumulating the products of this multiplication. After correlation, the index for the maximum or minimum peak of the despreading output samples for each code is identified. This index can then be mapped into a symbol corresponding to the transmitted information.Type: GrantFiled: June 23, 2004Date of Patent: April 29, 2008Assignee: Hyperband Communications, Inc.Inventors: Syang-Myau Hwang, Yiping Fan, Chen-Yi Chang, Hongyu Li, Chieh-Yuan Chao -
Patent number: 7079574Abstract: A method for a carrier phase recovery apparatus in a multiple-link hopping radio system includes hopping among a plurality of radio links to receive bursts of radio signals on the plurality of radio links and determining channel information for each radio link from a received burst on the radio link. Further, the method includes storing the determined channel information and using the determined channel information for the radio link to reliably recover the carrier phase of a next received burst on the radio link.Type: GrantFiled: January 17, 2001Date of Patent: July 18, 2006Assignee: Radiant Networks PLCInventors: Manouchehr S. Rafie, Tushar Shah, Syang-Myau Hwang, Jun Lu
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Publication number: 20050105597Abstract: In a spread spectrum system, methods and despreader architectures for despreading the received spreaded codes with the use of a single correlator and a single correlation code is provided. Before despreading the incoming received spreaded codes, a single correlation code is generated using a symbol from a set of symbols that has been mapped into a set of differential encoded PN codes. Despreading output samples for each received spreaded code are obtained by correlating the received spreaded code with this single correlation code. Correlation is accomplished by multiplying each received sample of the received spreaded codes with the correlation code samples and accumulating the products of this multiplication. After correlation, the index for the maximum or minimum peak of the despreading output samples for each code is identified. This index can then be mapped into a symbol corresponding to the transmitted information.Type: ApplicationFiled: June 23, 2004Publication date: May 19, 2005Inventors: Syang-Myau Hwang, Yiping Fan, Chen-Yi Chang, Hongyu Li, Chieh-Yuan Chao
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Publication number: 20050105596Abstract: A spread spectrum receiver whose de-spreading process based on transformed spreading codes is provided. Instead of de-spreading with original spreading codes, this approach de-spreads received signal with the spreading codes transformed from the original codes in order to eliminate the negative impact of system impairments such as frequency offset to a spread spectrum receiver. Before de-spreading with the transformed code, the received signal goes through the same transformation as the original codes do. After a transformation, the transformed codes may exist some undesirable property such as spreading code having DC content. An approach is given to cancel unwanted side effects relating the transformed spreading codes. The approaches are very effective for spread spectrum system based on frequency modulation scheme such as MSK.Type: ApplicationFiled: November 13, 2003Publication date: May 19, 2005Inventors: Yiping Fan, Syang-Myau Hwang, Hongyu Li, Chieh-Yuan Chao
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Patent number: 6532271Abstract: Method and system for carrier recovery and estimation of Doppler shift from a signal source that is moving relative to a signal receiver. A pure carrier preamble for the received signal is processed through each of two stages of a linear predictor to obtain a successively more accurate estimation of a Doppler frequency offset for the carrier. The received signal is downconverted by each stage estimation of the Doppler frequency offset, and the downconverted signal is processed through a decision feedback phase locked loop to provide a signal in which substantially all of the Doppler offset and/or phase angle are identified and removed. The system has low complexity, is fast, and is accurate to within an estimated few tens of Hertz and will work with signals having relatively low signal-to-noise ratios. The invention is useful for receipt of signals from satellites in low earth orbits (LEOs) and other non-geosynchronous orbits, and wherever a transmitter and receiver are moving relative to each other.Type: GrantFiled: October 29, 1999Date of Patent: March 11, 2003Assignee: Cadence Design Systems, Inc.Inventors: Syang-Myau Hwang, Lin Yang, Mao Yu, Gibong Jeong
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Publication number: 20020126748Abstract: A method for a carrier phase recovery apparatus in a multiple-link hopping radio system includes hopping among a plurality of radio links to receive bursts of radio signals on the plurality of radio links and determining channel information for each radio link from a received burst on the radio link. Further, the method includes storing the determined channel information and using the determined channel information for the radio link to reliably recover the carrier phase of a next received burst on the radio link.Type: ApplicationFiled: January 17, 2001Publication date: September 12, 2002Inventors: Manouchehr S. Rafie, Tushar Shah, Syang-Myau Hwang, Jun Lu