Patents by Inventor Bruce J. Currivan

Bruce J. 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).

  • Patent number: 7203227
    Abstract: All digital reference frequency locking. An all digital approach is provided for operation within one or more CMs within a cable modem communication system to lock the upstream of the one or more CMs to the downstream symbol clock provided from a CMTS. The locking of the CM's upstream may be performed using one of at least three different functions: (1) Locking the upstream symbol clock phase to the downstream symbol clock phase, (2) Locking the downstream symbol clock phase to the headend reference clock phase (typically 10.24 MHz or integer multiple thereof), and (3) Locking the upstream carrier frequency to the downstream symbol clock frequency. The all-digital techniques for supporting all digital reference frequency locking functionality provide high performance to support S-CDMA and other synchronous modulation techniques.
    Type: Grant
    Filed: November 14, 2002
    Date of Patent: April 10, 2007
    Assignee: Broadcom Corporation
    Inventors: Bruce J. Currivan, Ravi Bhaskaran, Thomas J. Kolze, Kevin Lee Miller, Jeffrey S. Putnam, Fang Lu, Tak K. Lee, Thuji S. Lin, Loke Kun Tan, Gopal Triplicane Venkatesan, Hsin-An Liu, Jonathan S. Min, James P. Cavallo
  • Patent number: 7136432
    Abstract: 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: Grant
    Filed: June 7, 2002
    Date of Patent: November 14, 2006
    Assignee: Broadcom Corporation
    Inventors: Jonathan S. Min, Fang Lu, Bruce J. Currivan, Tom Kwon
  • Patent number: 7110434
    Abstract: 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 are 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: Grant
    Filed: May 8, 2002
    Date of Patent: September 19, 2006
    Assignee: Broadcom Corporation
    Inventors: Bruce J. Currivan, Thomas J. Kolze, Gottfried Ungerboeck, Nabil R. Yousef
  • Patent number: 7104534
    Abstract: 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: Grant
    Filed: July 30, 2001
    Date of Patent: September 12, 2006
    Assignee: Broadcom Corporation
    Inventors: Bruce J. Currivan, Jonathan S. Min, Fang Lu
  • Patent number: 7050516
    Abstract: A system for periodic noise avoidance including a timing discriminator receiving an input signal from a communications channel. The input signal includes data packets and empty slots with periodic noise. The timing discriminator outputs a first error measurement of periodic noise width and a second error measurement of periodic noise position. A first loop filter inputs the first error measurement and outputs a width of the empty slots. A second loop filter inputs the second error measurement and outputs a frequency of the periodic noise. An oscillator inputs the width of the empty slots and the frequency, and outputs an empty slot waveform to the timing discriminator.
    Type: Grant
    Filed: March 20, 2003
    Date of Patent: May 23, 2006
    Assignee: Broadcom Corporation
    Inventors: Bruce J. Currivan, Thomas J. Kolze, Daniel H. Howard, Nabil Yousef, William Ngai
  • Patent number: 6798854
    Abstract: 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: Grant
    Filed: June 11, 2001
    Date of Patent: September 28, 2004
    Assignee: Broadcom Corporation
    Inventors: Thomas J. Kolze, Bruce J. Currivan, Jonathan S. Min, Eric Ojard, James Chi Thi, Daniel Howard
  • Publication number: 20040184571
    Abstract: A system for periodic noise avoidance including a timing discriminator receiving an input signal from a communications channel. The input signal includes data packets and empty slots with periodic noise. The timing discriminator outputs a first error measurement of periodic noise width and a second error measurement of periodic noise position. A first loop filter inputs the first error measurement and outputs a width of the empty slots. A second loop filter inputs the second error measurement and outputs a frequency of the periodic noise. An oscillator inputs the width of the empty slots and the frequency, and outputs an empty slot waveform to the timing discriminator.
    Type: Application
    Filed: March 20, 2003
    Publication date: September 23, 2004
    Applicant: Broadcom Corporation
    Inventors: Bruce J. Currivan, Thomas J. Kolze, Daniel H. Howard, Nabil Yousef, William Ngai
  • Publication number: 20040128696
    Abstract: A method of transmitting data in a cable modem system includes the steps of encoding the data using forward error correction. The data is then encoded with Turbo encoding. The data is then sent to a modulation scheme. The data is then transmitted over a cable channel. The data is then demodulated. The data is then decoded using a Turbo decoder. An inverse of the forward error correction is then applied to the data.
    Type: Application
    Filed: March 17, 2003
    Publication date: July 1, 2004
    Applicant: Broadcom Corporation
    Inventors: Ravi Bhaskaran, Bruce J. Currivan, Thomas J. Kolze, Ba-Zhong Shen
  • Publication number: 20040068748
    Abstract: 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: Application
    Filed: May 1, 2003
    Publication date: April 8, 2004
    Inventors: Bruce J. Currivan, Thomas J. Kolze, Daniel H. Howard, Gottfried Ungerboeck
  • Publication number: 20040008662
    Abstract: Multi-user CFO Correction for CDMA Systems. Any communication receiver may be adapted to perform the multi-user CFO correction for CDMA. One embodiment assumes a diagonal CFO matrix to decouple the different codes' soft symbol decisions, and each soft symbol decision is independently corrected to obtain hard decisions. Another embodiment employs direct CFO matrix inversion and multiplies it by a despread soft symbol decision vector to obtain corrected soft symbol decisions. Another embodiment first performs a single-user correction on the despread soft symbol decisions; these soft symbol decisions are then sliced to obtain initial hard decisions. In the next step of this embodiment, the initial hard decisions are multiplied by the CFO coefficients to obtain an estimate for the undesired ICI, which is then subtracted from the despread soft symbol decisions to obtain cleaner soft symbol decisions. The cleaner soft symbol decisions are sliced to obtain higher-order hard decisions.
    Type: Application
    Filed: August 22, 2002
    Publication date: January 15, 2004
    Inventors: Nabil R. Yousef, Jonathan S. Min, Bruce J. Currivan
  • Publication number: 20030185174
    Abstract: 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 are 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: Application
    Filed: May 8, 2002
    Publication date: October 2, 2003
    Inventors: Bruce J. Currivan, Thomas J. Kolze, Gottfried Ungerboeck, Nabil R. Yousef
  • Publication number: 20030177502
    Abstract: Enhanced DOCSIS upstream channel changes. A CMTS directs channel changing of a CM, sometimes between upstream data bursts. Logical channels, part of a single frequency channel, may be used, and the channel changing may be performed between those logical channels. Multiple upstream burst profiles and/or modulation densities may be used providing high degrees of robustness, fidelity, and throughput and allowing great channel flexibility. A CM may be switched between channels without losing transmitter capability. Even if some throughput rate may be sacrificed during the channel changing, the CM will still be able to continue data throughput. Then, the new channel may then undergo the initialization and ranging processes thereby enabling greater throughput on that new channel. After undergoing the initialization and ranging processes, the new channel will then be a fully equivalent member of the CM communication system.
    Type: Application
    Filed: May 6, 2002
    Publication date: September 18, 2003
    Inventors: Thomas J. Kolze, Bruce J. Currivan
  • Publication number: 20030159154
    Abstract: Outer code covered synchronous code division multiple access for cable modem (CM) channels. Outer pseudo-noise (PN) code is employed, along with orthogonal codes (OCs), to spread CM signals thereby mitigating inter-code-interference (ICI) effects caused by residual multi-path propagation within CM communication systems. The added and implemented PN sequences have relatively good autocorrelation properties (when compared to the autocorrelation properties of the OCs) that mask the possible bad autocorrelation and/or cross-correlation properties of the OCs. This outer-code covered PN coding, along with the OC coding, enables much better performance in the presence of residual multi-path. The PN code's added complexity is very minimal as the PN may use the same chip rate of the orthogonal code while providing for better performance in the presence of residual multi-path components.
    Type: Application
    Filed: February 20, 2002
    Publication date: August 21, 2003
    Inventors: Nabil R. Yousef, Bruce J. Currivan
  • Publication number: 20030031198
    Abstract: A system, method and computer program product is provided for mitigating the effects of burst noise on packets transmitted in a communications system. A transmitting device applies an outer code, which may include, for example, a block code, an exclusive OR (XOR) code, or a repetition code, to one or more packets prior to adaptation of the packets for transmission over the physical (PHY) layer of the communications system, wherein the PHY layer adaptation may include FEC encoding of individual packets. The outer coded packets are then separately transmitted over a channel of the communications system. A receiving device receives the outer coded packets, performs PHY level demodulation and optional FEC decoding of the packets, and then applies outer code decoding to the outer coded packets in order to restore packets that were erased during transmission due to burst noise or other impairments on the channel.
    Type: Application
    Filed: June 20, 2002
    Publication date: February 13, 2003
    Applicant: Broadcom Corporation
    Inventors: Bruce J. Currivan, Thomas J. Kolze, Daniel H. Howard, Tom Quigley, Nambi Seshadri, Thomas L. Johnson, Scott Cummings, Jay Harrell, Fred Bunn
  • Publication number: 20030031275
    Abstract: 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: Application
    Filed: June 7, 2002
    Publication date: February 13, 2003
    Inventors: Jonathan S. Min, Fang Lu, Bruce J. Currivan, Tom Kwon
  • Publication number: 20030026283
    Abstract: 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: Application
    Filed: July 30, 2001
    Publication date: February 6, 2003
    Applicant: Broadcom Corporation
    Inventors: Bruce J. Currivan, Jonathan S. Min, Fang Lu
  • Publication number: 20030021237
    Abstract: A method of managing traffic in a communications channel includes the steps of receiving a subscriber ID corresponding to a subscriber, performing a spectral analysis on a signal received from the subscriber within a time interval identified by the subscriber ID, and adjusting transmission characteristics of the subscriber based on the spectral analysis.
    Type: Application
    Filed: June 7, 2002
    Publication date: January 30, 2003
    Inventors: Jonathan S. Min, Fang Lu, Bruce J. Currivan, Kevin Eddy
  • Publication number: 20030021365
    Abstract: 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: Application
    Filed: June 7, 2002
    Publication date: January 30, 2003
    Inventors: Jonathan S. Min, Fang Lu, Bruce J. Currivan, Tom Kwon
  • Publication number: 20020186756
    Abstract: 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: Application
    Filed: April 30, 2002
    Publication date: December 12, 2002
    Inventors: Thomas J. Kolze, Bruce J. Currivan
  • Publication number: 20020094044
    Abstract: 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: Application
    Filed: June 11, 2001
    Publication date: July 18, 2002
    Inventors: Thomas J. Kolze, Bruce J. Currivan, Jonathan S. Min, Eric Ojard, James Chi Thi, Daniel Howard