Patents by Inventor Bruce Currivan
Bruce Currivan 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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Publication number: 20100046601Abstract: Various example embodiments are disclosed. According to an example embodiment, an apparatus may include a continuous time filter, a decision feedback equalizer, a clock and data recovery circuit, and an adaptation circuit. The adaptation circuit may be configured to adapt equalization according to at least one dithering algorithm by adjusting a delay adjust signal based on a mean square error of equalized data signals.Type: ApplicationFiled: October 27, 2009Publication date: February 25, 2010Applicant: Broadcom CorporationInventors: Afshin Momtaz, Mario Caresosa, David Chung, Davide Tonietto, Guangming Yin, Bruce Currivan, Thomas Kolze, Ichiro Fujimori
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Patent number: 7623600Abstract: Equalization is provided in a high speed communication receiver that includes in various aspects an automatic gain control input stage, a decision feedback equalizer, a clock and data recovery circuit and equalization control circuits. The automatic gain control stage may include a continuous time filter with an adjustable bandwidth. A threshold adjust signal may be applied to the output of the automatic gain control stage. The equalization control circuits may be implemented in the digital domain and operate at a lower clock speed than the data path.Type: GrantFiled: June 30, 2004Date of Patent: November 24, 2009Assignee: Broadcom CorporationInventors: Afshin Momtaz, Mario Caresosa, David Chung, Davide Tonietto, Guangming Yin, Bruce Currivan, Thomas Kolze, Ichiro Fujimori
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Publication number: 20090135896Abstract: An apparatus comprising a slicer configured to produce a symbol decision value and a symbol error value utilizing, at least in part, a slicer input signal; and an automatic gain controller configured to facilitate the automatic control of a gain applied to the slicer input signal by producing a gain control signal, the automatic gain controller comprising a decision-directed amplitude error detector configured to utilize, at least in part, the symbol decision value and the symbol error value to produce an amplitude error signal, and a loop filter configured to utilize the amplitude error signal to produce the gain control signal.Type: ApplicationFiled: November 27, 2007Publication date: May 28, 2009Applicant: BROADCOM CORPORATIONInventors: Bruce Currivan, Loke Tan, Thomas Kolze
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Publication number: 20090122874Abstract: Methods and systems for DVB-C2 are disclosed and may include receiving data encoded utilizing variable encoding, variable modulation and outer codes via a physical layer matched to a desired quality of service. An error probability may be determined for said received data and retransmission of portions of said data with error probability above an error threshold may be requested. The variable modulation may include single carrier modulation, orthogonal frequency division modulation, synchronous code division multiple access, and/or from 256 QAM to 2048 QAM or greater. The variable encoding may include forward error correction code, which may include low density parity check code.Type: ApplicationFiled: November 12, 2008Publication date: May 14, 2009Inventors: Thomas Kolze, Robbert van der Wal, Bruce Currivan
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Publication number: 20080107211Abstract: A method of parameter estimation in a shared channel communications system includes the steps of receiving a preamble including a first sequence corresponding to a sequence having zero autocorrelation, a second sequence having zero autocorrelation, and a third sequence having zero autocorrelation, performing a coarse carrier frequency estimate based on the first sequence, and performing a fine carrier frequency estimate based on the second and third sequences.Type: ApplicationFiled: January 4, 2008Publication date: May 8, 2008Applicant: Broadcom CorporationInventors: Jonathan Min, Fang Lu, Bruce Currivan, Tom Kwon
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Publication number: 20080098287Abstract: Systems and methods are disclosed for detecting temporary high level impairments, such as noise or interference, for example, in a communications channel, and subsequently, mitigating the deleterious effects of the dynamic impairments. In one embodiment, the method not only performs dynamic characterization of channel fidelity against impairments, but also uses this dynamic characterization of the channel fidelity to adapt the receiver processing and to affect an improvement in the performance of the receiver. For example, in this embodiment, the method increases the accuracy of the estimation of the transmitted information, or similarly, increases the probability of making the correct estimates of the transmitted information, even in the presence of temporary severe levels of impairment. The channel fidelity history may also be stored and catalogued for use in, for example, future optimization of the transmit waveform.Type: ApplicationFiled: December 11, 2007Publication date: April 24, 2008Inventors: Thomas Kolze, Bruce Currivan, Jonathan Min
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Publication number: 20080084952Abstract: The present invention relates a system and method for mitigating impairment in a communication system. In one embodiment, the system comprises a transmitter adapted to transmit at least one signal and a receiver adapted to receive the at least one signal and mitigate inter code interference in the signal using at least one inter code interference coefficient.Type: ApplicationFiled: December 12, 2007Publication date: April 10, 2008Inventors: Thomas Kolze, Bruce Currivan
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Patent number: 7308050Abstract: Systems and methods are disclosed for detecting temporary high level impairments, such as noise or interference, for example, in a communications channel, and subsequently, mitigating the deleterious effects of the dynamic impairments. In one embodiment, the method not only performs dynamic characterization of channel fidelity against impairments, but also uses this dynamic characterization of the channel fidelity to adapt the receiver processing and to affect an improvement in the performance of the receiver. For example, in this embodiment, the method increases the accuracy of the estimation of the transmitted information, or similarly, increases the probability of making the correct estimates of the transmitted information, even in the presence of temporary severe levels of impairment. The channel fidelity history may also be stored and catalogued for use in, for example, future optimization of the transmit waveform.Type: GrantFiled: November 2, 2001Date of Patent: December 11, 2007Assignee: Broadcom CorporationInventors: Thomas Kolze, Bruce Currivan, Jonathan Min
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Publication number: 20070201590Abstract: A filter settings generation operation includes sampling a communication channel to produce a sampled signal. The sampled signal is spectrally characterized across a frequency band of interest to produce a spectral characterization of the sampled signal. This spectral characterization may not include a signal of interest. The spectral characterization is then modified to produce a modified spectral characterization. Filter settings are then generated based upon the modified spectral characterization. Finally, the communication channel is filtered using the filter settings when the signal of interest is present on the communication channel. In modifying the spectral characterization, pluralities of spectral characteristics of the spectral characterization are independently modified to produce the modified spectral characterization. Modifications to the spectral characterization may be performed in the frequency domain and/or the time domain.Type: ApplicationFiled: April 24, 2007Publication date: August 30, 2007Applicant: Broadcom Corporation, a California CorporationInventors: Thomas Kolze, Bruce Currivan, Jonathan Min, Eric Ojard, James Thi, Daniel Howard
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Publication number: 20070115349Abstract: Herein described is a system and method that tracks the face of a person engaged in a videophone conversation. In addition to performing facial tracking, the invention provides stabilization of facial images that are transmitted during the videophone conversation. The face is tracked by employing one or more algorithms that correlate videophone captured facial images against a stored facial image. The face may be better identified by way of employing one or more voice recognition algorithms. The one or more voice recognition algorithms may correlate utterances of the person engaged in a conversation to one or more stored utterances. The identified utterances are subsequently mapped to a stored facial image. In a representative embodiment, the system used for performing facial tracking and image stabilization comprises an image sensor, a lens, an actuator, and a controller/processor.Type: ApplicationFiled: November 3, 2005Publication date: May 24, 2007Inventors: Bruce Currivan, Xuemin Chen
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Publication number: 20070115350Abstract: Herein described is a system and method for modifying facial video transmitted from a first videophone to a second videophone during a videophone conversation. A videophone comprises a videophone image processing system (VIPS) that stores one or more preferred images. The one or more preferred images may comprise an image of a person presented in an attractive appearance. The one or more preferred images may comprise one or more avatars. Additionally, the VIPS may be used to incorporate one or more facial features of the person into a preferred image or avatar. Furthermore, a replacement background may be incorporated into the preferred image or avatar. The VIPS transmits a preferred image of a first speaker of a first videophone to a second speaker of a second videophone by capturing an actual image of the first speaker and substituting at least a portion of said actual image with a stored image.Type: ApplicationFiled: November 3, 2005Publication date: May 24, 2007Inventors: Bruce Currivan, Xuemin Chen
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Publication number: 20070061642Abstract: A system and method are used to provide uncorrelated code hopping in a communications system. A multi-bit linear shift register receives data and clocks the data fifteen times. A word assembler receives the shifted data and outputs a fifteen bit word. A mixer mixes the fifteen bit word with an numerical value of active codes to generate a mixed signal. A divider divides the mixed signal to produce a divided signal. A truncator truncates the divided signal to its seven most significant bits to produce a pseudo random hop number. A code matrix shifter circularly shifts the active codes in a code matrix based on the pseudo random hop number to produce a circularly shifted code. A transmitter transmits the circularly shifted code matrix.Type: ApplicationFiled: July 20, 2006Publication date: March 15, 2007Applicant: Broadcom CorporationInventors: Bruce Currivan, Thomas Kolze, Kevin Miller, Richard Prodan, Jonathan Min
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Publication number: 20070014334Abstract: Cancellation of interference in a communication system with application to S-CDMA. A relatively straight-forward implemented and computationally efficient approach of selecting a predetermined number of unused codes is used to perform weighted linear combination selectively with each of the input spread signals in a multiple access communication system. If desired, the predetermined number of unused codes is always the same in each implementation. Alternatively, the predetermined number of unused codes is selected from within a reordered code matrix using knowledge that is shared between the two ends of a communication system, such as between the CMs and a CMTS. While the context of an S-CDMA communication system having CMs and a CMTS is used, the solution is generally applicable to any communication system that seeks to cancel narrowband interference. Several embodiments are also described that show the generic applicability of the solution across a wide variety of systems.Type: ApplicationFiled: September 18, 2006Publication date: January 18, 2007Applicant: Broadcom Corporation, a California CorporationInventors: Bruce Currivan, Thomas Kolze, Gottfried Ungerboeck, Nabil Yousef
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Publication number: 20070004360Abstract: The present invention is directed to systems and method for attenuating intermodulation interference. In particular, methods and systems to attenuate intermodulation interference contained within an aggregate signal having a transmitted signal that was transmitted over a communications channel having channel effects that produce the intermodulation interference are provided. The communications channel may be a cable television distribution network and the signal may be a cable television signal. A method is provided to predict when intermodulation interference will be large, so that actions within a receiver can be taken to reduce the impact of the interference and improve overall receiver performance.Type: ApplicationFiled: September 6, 2005Publication date: January 4, 2007Applicant: Broadcom CorporationInventor: Bruce Currivan
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Publication number: 20060274778Abstract: A system for detecting collisions in a shared communications medium, such as a TDMA medium, includes a receive path adapted to generate a first intermediate signal, a second intermediate signal, and a data symbol sequence from an input signal. A preamble detection module generates a correlation metric from the first intermediate signal. A power measurement module generates a power indication signal from the second intermediate signal. A noise measurement module generates a noise indication signal from the second intermediate signal and the data symbol sequence. A processing module is adapted to characterize the input signal as a collision for certain values of correlation metric, power indication signal, and noise indication signal.Type: ApplicationFiled: July 20, 2006Publication date: December 7, 2006Applicant: Broadcom CorporationInventors: Bruce Currivan, Jonathan Min, Fang Lu
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Publication number: 20060056323Abstract: A distributed Cable Modem Termination System (CMTS) includes a head end, a downstream transmitter hub, and a plurality of cable modems that all establish frequency lock with a common frequency reference. The head end transmits a plurality of time stamps from the head end to the plurality of cable modems via a packet data network, the downstream transmitter hub, and cable modem network plant. Each of the plurality of cable modems performs smoothing operations on the plurality of time stamps to establish phase lock with the head end. The downstream transmitter and the plurality of cable modems perform ranging operations to establish phase lock among the plurality of cable modems. In an alternate operation, the frequency reference includes marker sequences that the devices of the distributed CMTS use to establish phase lock.Type: ApplicationFiled: August 31, 2005Publication date: March 16, 2006Inventor: Bruce Currivan
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Publication number: 20060056461Abstract: A distributed cable modem termination system of the present invention includes a downstream transmitter hub, an upstream receiver hub, and a head end that communicatively couples to the downstream transmitter hub and to the upstream receiver hub via a packet data network. The head end and the downstream transmitter hub are operable to synchronize a clock of the downstream transmitter hub with a clock of the head end. Further, the upstream receiver hub and the downstream transmitter hub are operable to synchronize a clock of the upstream receiver hub with the clock of the downstream transmitter hub. Clock synchronization between the upstream receiver hub and the downstream transmitter hub are performed using ranging operations supported by at least one cable modem communicatively coupled to both the upstream receiver hub and the downstream transmitter hub via cable modem network plant.Type: ApplicationFiled: February 18, 2005Publication date: March 16, 2006Inventors: Bruce Currivan, Alexander MacInnis, Thomas Kolze, Richard Prodan
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Publication number: 20060056460Abstract: A distributed CMTS includes a head end, a downstream transmitter hub, and an upstream receiver hub. The head end transmits data packets to the downstream transmitter via a coupling packet data network. Each data packet is marked with a “measured delay” Quality of Service (QOS) and includes a time stamp that is based upon a clock of the head end and a delay tag. The downstream transmitter hub receives the plurality of data, adjusts the time stamps based upon the delay tags, smoothes the time stamps of the plurality of data packets and, based upon the smoothed time stamps, synchronizes its clock with the clock of the head end. The downstream transmitter hub then synchronizes a clock of the upstream receiver hub with the clock of the downstream transmitter hub. The upstream receiver hub may synchronize its clock to the clock of the head end using this technique.Type: ApplicationFiled: January 6, 2005Publication date: March 16, 2006Inventor: Bruce Currivan
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Publication number: 20060041918Abstract: Signal processing under attenuated transmission conditions. Within an orthogonal signal space, the number of orthogonal signals that are used to transmit information from a transmitter to a receiver is reduced and the transmitted power of each of the now remaining orthogonal signals is modified; this may involve increasing the power of all of the remaining orthogonal signals equally or alternatively modifying them individually. The same modulation used before the reduction may also be used afterwards; within communication systems having multiple transmitter-receiver paths, this will ensure that the communication system's throughput and efficiency will remain unchanged even when one (or more) transmitter-receiver paths are highly attenuated. In addition, robust mode operation is provided for ranging and registering of transmitter devices when entering the communication system.Type: ApplicationFiled: May 1, 2003Publication date: February 23, 2006Inventors: Bruce Currivan, Thomas Kolze, Daniel Howard, Gottfried Ungerboeck
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Publication number: 20060039459Abstract: Provided is a method and system for estimating distortion in a communications channel including an adaptive equalizer. The method includes determining one or more adaptive filter coefficients associated with a signal passed through the equalizer. The method also includes estimating un-equalized channel distortion based upon the determined adaptive filter coefficients.Type: ApplicationFiled: February 1, 2005Publication date: February 23, 2006Applicant: Broadcom CorporationInventors: Thomas Kolze, Bruce Currivan