Patents by Inventor Raul Casas
Raul Casas 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: 8498352Abstract: A digital communications receiver includes an input configured to receive, via a communications channel, a received first signal representing a sequence of symbols, each symbol being encoded to be representative of a plurality of data bits. A processor adjusts a magnitude and filters the received signal. An equalizer applies a cyclic prefix restoration to the adjusted and filtered signal, producing a second signal, converts the second signal from time domain to frequency domain to produce a frequency domain signal, and determines a first quantity of values representing a first portion of the symbols by evaluating a relationship of channel values representing characteristics of the communications channel and a second quantity of values representing a portion of the frequency domain signal, the first quantity being smaller than the second quantity.Type: GrantFiled: November 7, 2011Date of Patent: July 30, 2013Assignee: ATI Technologies ULCInventors: Hong Liu, Raul A. Casas, Haosung Fu
-
Publication number: 20120051412Abstract: A digital communications receiver includes an input configured to receive, via a communications channel, a received first signal representing a sequence of symbols, each symbol being encoded to be representative of a plurality of data bits. A processor adjusts a magnitude and filters the received signal. An equalizer applies a cyclic prefix restoration to the adjusted and filtered signal, producing a second signal, converts the second signal from time domain to frequency domain to produce a frequency domain signal, and determines a first quantity of values representing a first portion of the symbols by evaluating a relationship of channel values representing characteristics of the communications channel and a second quantity of values representing a portion of the frequency domain signal, the first quantity being smaller than the second quantity.Type: ApplicationFiled: November 7, 2011Publication date: March 1, 2012Applicant: ATI TECHNOLOGIES ULCInventors: Hong Liu, Raul A. Casas, Haosong Fu
-
Patent number: 8054900Abstract: In a digital communications receiver configured to receive, via a communications channel, a received first signal representing a sequence of symbols, each symbol being encoded to be representative of data bits, a method of processing the received signal includes adjusting a magnitude, filtering, and applying cyclic prefix restoration, to the received signal to produce a second signal, converting the second signal from time domain to frequency domain to produce a frequency domain signal, and determining a first quantity of values representing a first portion of the symbols by evaluating a relationship of channel values representing characteristics of the communications channel and a second quantity of values representing a portion of the frequency domain signal, the first quantity being smaller than the second quantity.Type: GrantFiled: May 13, 2009Date of Patent: November 8, 2011Assignee: ATI Technologies, Inc.Inventors: Hong Liu, Raul A. Casas, Haosung Fu
-
Patent number: 7873101Abstract: A digital filter pre-calculates C(1)*S(n?1), C(2)*S(n?2) . . . C(p?1)*S(n?p+1), prior to the arrival of sample S(n). As such y ? ( n ) = ? k = 0 k = p - 1 ? C ? ( k ) * S ? ( n - k ) may be calculated as a result of a single further multiply and accumulate operation, upon arrival of the symbol S(n). This, significantly reduces the latency of the filter.Type: GrantFiled: March 25, 2005Date of Patent: January 18, 2011Assignee: Broadcom CorporationInventors: Raghuram P. Behara, Thomas J. Meyer, Yiwen Yu, Ajay Bhaskaran, Raul A. Casas
-
Patent number: 7750978Abstract: An audio/video separator provides a high-performance and cost-effective solution to analog TV reception with only one A/D converter and a minimum of analog IF components. The apparatus may operate on a digitized TV signal and, when integrated with a digital video processor, process video signals while separating audio signals. The resultant audio and video signals may be considered to have excellent signal quality due to highly optimized demodulation architecture and digital signal processing techniques on both audio and video data paths.Type: GrantFiled: January 7, 2009Date of Patent: July 6, 2010Assignee: Broadcom CorporationInventors: Daniel Q. Zhu, Hulyalkar N. Samir, Binning Chen, Raul A. Casas, Dongsheng Wu
-
Patent number: 7733422Abstract: An apparatus, for use in a receiver configured to receive electronic signals, for identifying digital signals that are available for reception, includes a timing recovery device configured to receive an incoming signal, related to a transmitted signal, the incoming signal having a first symbol rate, and to re-sample the incoming signal to provide a second symbol rate, and an analyzer that is in communication with the timing recovery device and that is configured to make a determination as to whether a difference between the second symbol rate and a third symbol rate of a transmitter providing the transmitted signal is within an acceptable tolerance and to use the determination in an analysis of whether the transmitted signal is available for reception.Type: GrantFiled: August 10, 2009Date of Patent: June 8, 2010Assignee: ATI Technologies, Inc.Inventors: Rajan Aggarwal, Mark Hryszko, Samuel H. Reichgott, Punyabrata Ray, Stephen L. Biracree, Binning Chen, Raul A. Casas
-
Publication number: 20090295995Abstract: An apparatus, for use in a receiver configured to receive electronic signals, for identifying digital signals that are available for reception, includes a timing recovery device configured to receive an incoming signal, related to a transmitted signal, the incoming signal having a first symbol rate, and to re-sample the incoming signal to provide a second symbol rate, and an analyzer that is in communication with the timing recovery device and that is configured to make a determination as to whether a difference between the second symbol rate and a third symbol rate of a transmitter providing the transmitted signal is within an acceptable tolerance and to use the determination in an analysis of whether the transmitted signal is available for reception.Type: ApplicationFiled: August 10, 2009Publication date: December 3, 2009Applicant: ATI Technologies, Inc.Inventors: Rajan Aggarwal, Mark Hryszko, Samuel H. Reichgott, Punyabrata Ray, Stephen L. Biracree, Binning Chen, Raul A. Casas
-
Publication number: 20090262864Abstract: In a digital communications receiver configured to receive, via a communications channel, a received first signal representing a sequence of symbols, each symbol being encoded to be representative of data bits, a method of processing the received signal includes adjusting a magnitude, filtering, and applying cyclic prefix restoration, to the received signal to produce a second signal, converting the second signal from time domain to frequency domain to produce a frequency domain signal, and determining a first quantity of values representing a first portion of the symbols by evaluating a relationship of channel values representing characteristics of the communications channel and a second quantity of values representing a portion of the frequency domain signal, the first quantity being smaller than the second quantity.Type: ApplicationFiled: May 13, 2009Publication date: October 22, 2009Applicant: ATI TECHNOLOGIES, INC.Inventors: Hong Liu, Raul A. Casas, Haosong FU
-
Patent number: 7573531Abstract: An apparatus, for use in a receiver configured to receive electronic signals, for identifying digital signals that are available for reception, includes a timing recovery device configured to receive an incoming signal, related to a transmitted signal, the incoming signal having a first symbol rate, and to re-sample the incoming signal to provide a second symbol rate, and an analyzer that is in communication with the timing recovery device and that is configured to make a determination as to whether a difference between the second symbol rate and a third symbol rate of a transmitter providing the transmitted signal is within an acceptable tolerance and to use the determination in an analysis of whether the transmitted signal is available for reception.Type: GrantFiled: October 14, 2005Date of Patent: August 11, 2009Assignee: ATI Technologies, Inc.Inventors: Rajan Aggarwal, Mark Hryszko, Samuel H. Reichgott, Punyabrata Ray, Stephen L. Biracree, Binning Chen, Raul A. Casas
-
Patent number: 7551679Abstract: In a digital communications receiver configured to receive, via a communications channel, a received first signal representing a sequence of symbols, each symbol being encoded to be representative of data bits, a method of processing the received signal includes adjusting a magnitude, filtering, and applying cyclic prefix restoration, to the received signal to produce a second signal, converting the second signal from time domain to frequency domain to produce a frequency domain signal, and determining a first quantity of values representing a first portion of the symbols by evaluating a relationship of channel values representing characteristics of the communications channel and a second quantity of values representing a portion of the frequency domain signal, the first quantity being smaller than the second quantity.Type: GrantFiled: February 3, 2006Date of Patent: June 23, 2009Assignee: ATI Technologies, Inc.Inventors: Hong Liu, Raul A. Casas, Haosong Fu
-
Patent number: 7551699Abstract: A method for selecting an antenna direction setting for optimum signal reception prior to channel equalization provides a set of metrics, referred to as channel quality metrics (CQM), that characterize the quality of the received signal for a given antenna setting and a generic algorithm that uses these metrics to select the antenna setting for an optimum reception. This invention utilizes five main CQMs: a Signal Strength Metric (SSM), a minimum mean squared error of a decision feedback equalizer (MMSE (DFE)) channel quality metric, a MMSE for a linear equalizer (MMSE(LE)) channel quality metric, a Spectral Flatness Metric (SFM) and an interference degradation metric (IDM).Type: GrantFiled: September 15, 2003Date of Patent: June 23, 2009Assignee: ATI Technologies, Inc.Inventors: Samuel H. Reichgott, Raul A. Casas, Samir N. Hulyalkar, Azzedine Touzni, John J. Zygmaniak, Andrew E. Youtz
-
Publication number: 20090115903Abstract: An audio/video separator provides a high-performance and cost-effective solution to analog TV reception with only one A/D converter and a minimum of analog IF components. The apparatus may operate on a digitized TV signal and, when integrated with a digital video processor, process video signals while separating audio signals. The resultant audio and video signals may be considered to have excellent signal quality due to highly optimized demodulation architecture and digital signal processing techniques on both audio and video data paths.Type: ApplicationFiled: January 7, 2009Publication date: May 7, 2009Inventors: Daniel Q. Zhu, Hulyalkar N. Samir, Binning Chen, Raul A. Casas, Dongsheng Wu
-
Publication number: 20090067483Abstract: The present invention is related to the digital implementation of adaptive equalizers for high-speed communication systems, using finite precision arithmetic, for example, as implemented in a silicon ASIC.Type: ApplicationFiled: August 26, 2008Publication date: March 12, 2009Inventors: Raul Casas, Stephen Leonard Biracree, Slobodan Simovich, Thomas Joseph Endres
-
Patent number: 7477325Abstract: An audio/video separator provides a high-performance and cost-effective solution to analog TV reception with only one A/D converter and a minimum of analog IF components. The apparatus may operate on a digitized TV signal and, when integrated with a digital video processor, process video signals while separating audio signals. The resultant audio and video signals may be considered to have excellent signal quality due to highly optimized demodulation architecture and digital signal processing techniques on both audio and video data paths.Type: GrantFiled: March 29, 2004Date of Patent: January 13, 2009Assignee: ATI Technologies, Inc.Inventors: Daniel Q. Zhu, Hulyalkar N. Samir, Binning Chen, Raul A. Casas, Dongsheng Wu
-
Publication number: 20080123787Abstract: The present invention is directed to a method and system for detecting and compensating for signal impairments in modulated signals. Phase noise and gain noise based signal impairments can be detected as a function of the difference between the optimal position in the constellation grid (the center) and the actual position in the constellation grid of a received symbol. As symbols are received, they are compared to optimal positions and a measure of the phase noise and gain noise can be determined for each symbol. Over a period of time, the detector can compute an average measure of phase noise and gain noise. When the average measure of phase noise and/or gain noise reaches a predefined threshold, the detector can indicate a phase noise based and/or gain noise based signal impairment has been detected to the receiver. The receiver can adjust one or more receive parameters in order to improve reception.Type: ApplicationFiled: November 29, 2007Publication date: May 29, 2008Inventors: Supat Wongwirawat, Mark Hryszko, Devan Namboodiri, Raul A. Casas
-
Publication number: 20080123786Abstract: The present invention is directed to a method and system for detecting and compensating for signal impairments in modulated signals. Phase noise and gain noise based signal impairments can be detected as a function of the difference between the optimal position in the constellation grid (the center) and the actual position in the constellation grid of a received symbol. As symbols are received, they are compared to optimal positions and a measure of the phase noise and gain noise can be determined for each symbol. Over a period of time, the detector can compute an average measure of phase noise and gain noise. When the average measure of phase noise and/or gain noise reaches a predefined threshold, the detector can indicate a phase noise based and/or gain noise based signal impairment has been detected to the receiver. The receiver can adjust one or more receive parameters in order to improve reception.Type: ApplicationFiled: November 29, 2007Publication date: May 29, 2008Inventors: Supat Wongwirawat, Mark Hryszko, Devan Namboodiri, Raul A. Casas
-
Publication number: 20080123788Abstract: The present invention is directed to a method and system for detecting and compensating for signal impairments in modulated signals. Phase noise and gain noise based signal impairments can be detected as a function of the difference between the optimal position in the constellation grid (the center) and the actual position in the constellation grid of a received symbol. As symbols are received, they are compared to optimal positions and a measure of the phase noise and gain noise can be determined for each symbol. Over a period of time, the detector can compute an average measure of phase noise and gain noise. When the average measure of phase noise and/or gain noise reaches a predefined threshold, the detector can indicate a phase noise based and/or gain noise based signal impairment has been detected to the receiver. The receiver can adjust one or more receive parameters in order to improve reception.Type: ApplicationFiled: November 29, 2007Publication date: May 29, 2008Inventors: Supat Wongwirawat, Mark Hryszko, Devan Namboodiri, Raul A. Casas
-
Patent number: 7349469Abstract: A single-axis receiver processes, for example, a complex vestigial sideband (VSB) modulated signal with an equalizer accounting for DC offset within the modulated signal. The DC offset embedded in a received signal may degrade the process of equalization. The equalizer includes a method of blind estimation of the DC offset for removing the DC offset. The estimate is generated by jointly minimizing a Constant Modulus (CM) cost function over equalizer parameters and a DC offset estimate. An arbitrary DC offset the CM cost function admits local spurious minima in terms of the equalizer function. If the DC offset at the receiver is equal to the DC offset inserted at the transmitter, which is equivalent to neglecting the ISI caused by the channel, then only half of the CM equalizer minima remain unchanged.Type: GrantFiled: August 7, 2002Date of Patent: March 25, 2008Assignee: ATI Research, Inc.Inventors: Azzédine Touzni, Thomas J. Endres, Haosong Fu, Raúl A. Casas, Christopher H. Strolle
-
Patent number: 7342981Abstract: A digital receiver, that may be used to receive VSB/QAM digital television signals, includes an adaptive fine carrier recovery circuit that compensates for deviations in the carrier frequency or phase. The carrier recovery circuit de-rotates a signal including phase errors. Estimations of phase errors are filtered using a filter whose gain and bandwidth are adjusted adaptively. This allows the carrier recovery circuit to track phase/frequency offset without introducing significant jitter. In one embodiment, the receiver includes a DFE, and the adaptive carrier recovery circuit mitigates instability that might be associated with the DFE.Type: GrantFiled: January 15, 2004Date of Patent: March 11, 2008Assignee: ATI Technologies Inc.Inventors: Supat Wongwirawat, Azzedine Touzni, Mark Hryszko, Raul A. Casas, Yiwen Yu
-
Publication number: 20070183452Abstract: An apparatus, configured to receive from a receiver a multiplexed data stream of multiplexed video data packets, the multiplexed data stream being produced from multiple input video streams received by the receiver. The apparatus includes a point-of-deployment (POD) module controller configured to use a POD module to decrypt the multiplexed data stream and a demultiplexor connected to the decryption module and configured to demultiplex the multiplexed data stream such that the video data packets are grouped in respective output video data streams, the demultiplexor being further configured to use timing information associated with the multiplexed data stream such that packets in the output video data streams have time spacings in accordance with the timing information.Type: ApplicationFiled: February 3, 2006Publication date: August 9, 2007Inventors: Mark Hryszko, Raul Casas, Samir Hulyalkar