Patents by Inventor Ravi Bhaskaran

Ravi Bhaskaran 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).

  • Publication number: 20070147281
    Abstract: Satellite communications are carried out using the Data Over Cable Interface Specification (DOCSIS). Satellite modems are notified of upstream channel congestion by inserting a congestion notification message in a medium access protocol (MAP) message for the upstream channel. Specifically, the congestion notification message is inserted in an unused field of the MAP message, such as the explicit congestion notification (ECN) field. The MAP message can also carry other characteristics of the upstream channel, including priority threshold, multicast access burst availability, and available bandwidth.
    Type: Application
    Filed: December 5, 2006
    Publication date: June 28, 2007
    Applicant: Broadcom Corporation
    Inventors: Mark Dale, David Hartman, Dorothy Lin, Rocco Brescia, Alan Gin, Ravi Bhaskaran, Jen-chieh Chien, Adel Fanous
  • 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: 7145888
    Abstract: Satellite communications are carried out using the Data Over Cable Interface Specification (DOCSIS). Satellite modems are notified of upstream channel congestion by inserting a congestion notification message in a medium access protocol (MAP) message for the upstream channel. Specifically, the congestion notification message is inserted in an unused field of the MAP message, such as the explicit congestion notification (ECN) field. The MAP message can also carry other characteristics of the upstream channel, including priority threshold, multicast access burst availability, and available bandwidth.
    Type: Grant
    Filed: April 23, 2003
    Date of Patent: December 5, 2006
    Assignee: Broadcom Corporation
    Inventors: Mark Dale, David Hartman, Dorothy Lin, Rocco Brescia, Alan Gin, Ravi Bhaskaran, Jen-chieh Chien, Adel Fanous
  • Publication number: 20040146038
    Abstract: A system and method for providing upstream adaptive modulation. Burst parameters associated with a range of data interval usage codes (IUCs) are defined. Each of the data IUCs has a different modulation order and forward error correction (FEC). The SNR and codeword error rate for each satellite modem in the network are monitored. The data IUCs are dynamically assigned to different satellite modems within an upstream channel based on SNR and/or codeword error rate to enable each of the satellite modems in the upstream channel to achieve maximum bandwidth efficiency during upstream data transmissions. Bandwidth requests are received from the satellite modems and granted. The grant includes the assigned data IUC. The data bursts received in the upstream channel are each processed using the parameters from the assigned IUC for each of the satellite modems sending data in the upstream channel.
    Type: Application
    Filed: January 28, 2003
    Publication date: July 29, 2004
    Inventors: Mark Dale, David L. Hartman, Dorothy D. Lin, Rocco J. Brescia, Alan Gin, Ravi Bhaskaran, Jen-chieh Chien, Adel Fanous
  • 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: 20040042574
    Abstract: A system and method for minimizing the frequency error of satellite modem signals at a satellite gateway. The gateway downstream baud (symbol) clock and the elements that control the upstream frequency (i.e., local oscillators in the conversion chain, A/D sample clocks) are locked to a common frequency reference. The gateway sends upstream satellite frequency offset information, such as satellite ephemeris data from which to calculate Doppler offset, to the satellite modem. The satellite modem locks the frequency of the satellite modems master oscillator to the recovered baud rate using a frequency locked loop. The satellite modem uses its master oscillator as the carrier reference for the upstream frequency up conversion. The satellite modem uses or calculates the upstream satellite frequency offset and compensates for this offset by shifting its center frequency.
    Type: Application
    Filed: January 28, 2003
    Publication date: March 4, 2004
    Inventors: Dorothy D. Lin, Alan Gin, David L. Hartman, Rocco J. Brescia,, Ravi Bhaskaran, Jen-Chieh Chien, Adel Fanous
  • Publication number: 20040017830
    Abstract: A method, apparatus and computer program product for generating and processing upstream channel descriptor (UCD) messages in a DOCSIS-based broadband communications system, such as a DOCSIS-based two-way satellite communications system, is provided. A satellite modem termination system (SMTS) generates a UCD message that includes one or more standard parameters pertaining to an upstream channel of the two-way satellite communications system, wherein the one or more standard parameters are defined in accordance with the DOCSIS protocol, and one or more satellite application-specific parameters pertaining to the upstream channel, wherein the one or more satellite application specific parameters are not provided for by the DOCSIS protocol. The UCD message is transmitted to a satellite modem that extracts both the standard and satellite application-specific parameters for use in managing communication over the upstream channel.
    Type: Application
    Filed: April 23, 2003
    Publication date: January 29, 2004
    Applicant: Broadcom Corporation
    Inventors: Mark Dale, David Hartman, Dorothy Lin, Rocco Brescia, Alan Gin, Ravi Bhaskaran, Jen-chieh Chien, Adel Fanous
  • Patent number: 6665355
    Abstract: An inexpensive synchronous detection module is disclosed for a sideband signal receiver that provides for flexibility in design of the tuner. The detection module is adaptable to detection of upper or lower sideband signals. One embodiment includes an analog-to-digital converter, a Hilbert transform filter, a sideband selection switch, a complex multiplier, a carrier recovery. loop, a matched filter, and a decimator. The analog-to-digital converter oversamples an intermediate frequency (IF) signal from the tuner, and the Hilbert transform filter generates a Hilbert transform of the digital IF signal. An analytic IF signal can be generated from the digital IF signal by multiplying the Hilbert transform of the digital IF signal by j(=sqrt(−1)), and adding the resulting imaginary-valued signal to the digital IF signal. The sideband selection switch can “flip” the analytic IF signal by inverting the imaginary-valued signal.
    Type: Grant
    Filed: September 8, 1999
    Date of Patent: December 16, 2003
    Assignee: LSI Logic Corporation
    Inventors: Ting-Yin Chen, Ravi Bhaskaran, Christopher Keate, Kedar D. Shirali
  • Publication number: 20030199248
    Abstract: Satellite communications are carried out using the Data Over Cable Interface Specification (DOCSIS). Satellite modems are notified of upstream channel congestion by inserting a congestion notification message in a medium access protocol (MAP) message for the upstream channel. Specifically, the congestion notification message is inserted in an unused field of the MAP message, such as the explicit congestion notification (ECN) field. The MAP message can also carry other characteristics of the upstream channel, including priority threshold, multicast access burst availability, and available bandwidth.
    Type: Application
    Filed: April 23, 2003
    Publication date: October 23, 2003
    Applicant: Broadcom Corporation
    Inventors: Mark Dale, David Hartman, Dorothy Lin, Rocco Brescia, Alan Gin, Ravi Bhaskaran, Jen-chieh Chien, Adel Fanous
  • Patent number: 6549591
    Abstract: Digital interference rejection of a signal is accomplished by first converting the signal to digital. Then a second signal is generated and mixed with the first signal. This combined signal is then filtered. The signal can then be scaled as needed, resulting in a finely tuned, interference free signal.
    Type: Grant
    Filed: November 13, 2000
    Date of Patent: April 15, 2003
    Assignee: LSI Logic Corporation
    Inventors: Christopher Keate, Ravi Bhaskaran, Dariush Dabiri
  • Patent number: 6167098
    Abstract: Digital interference rejection of a signal is accomplished by first converting the signal to digital. Then a second signal is generated and mixed with the first signal. This combined signal is then filtered. The signal can then be scaled as needed, resulting in a finely tuned, interference free signal.
    Type: Grant
    Filed: January 16, 1998
    Date of Patent: December 26, 2000
    Assignee: LSI Logic Corporation
    Inventors: Christopher Keate, Ravi Bhaskaran, Dariush Dabiri
  • Patent number: 5926489
    Abstract: A communications receiver system is presented for detecting burst errors and providing erasure information to a block decoder, thereby effectively doubling the conventional correction capability of the block decoder with only a minimal increase in complexity. In one embodiment, the receiver includes a demodulator which includes circuitry to detect error bursts in the received symbol sequence. Once detected, the locations of symbols in error are marked in the form of erasure flags. An error correction decoder is then able to correct up to twice as many errors with the additional information provided by the erasure flags.
    Type: Grant
    Filed: November 22, 1996
    Date of Patent: July 20, 1999
    Assignee: LSI Logic Corporation
    Inventors: Daniel A. Luthi, Ravi Bhaskaran, Dojun Rhee, Advait M. Mogre
  • Patent number: 5812603
    Abstract: A communications receiver system is presented for detecting burst errors and providing erasure information to the block decoder, thereby effectively doubling the conventional correction capability of the block decoder with only a minimal increase in complexity. In one embodiment, this mechanism takes the form of a circuit which re-encodes the output of the inner decoder, compares it with the received sequence of code symbols, and flags a portion of the inner decoder output for erasure when an excessive number of code symbol errors are detected. In a second embodiment, this mechanism takes the form of a circuit which makes hard symbol decisions on the channel signal, compares the hard decisions to the channel signal to determine a noise level, and thereafter flags the channel output in regions with excessive noise levels.
    Type: Grant
    Filed: August 22, 1996
    Date of Patent: September 22, 1998
    Assignee: LSI Logic Corporation
    Inventors: Daniel A. Luthi, Ravi Bhaskaran, Dojun Rhee, Advait M. Mogre
  • Patent number: 5708665
    Abstract: A communications receiver system is presented for detecting burst errors and providing erasure information to the block decoder (outer decoder), thereby effectively doubling the conventional correction capability of the block decoder with only a minimal increase in complexity. In one embodiment, this mechanism takes the form of a circuit which re-encodes the output of the inner decoder, compares it with the received sequence of code symbols, and flags a portion of the inner decoder output for erasure when an excessive number of code symbol errors are detected. In a second embodiment, this mechanism takes the form of a circuit which makes hard symbol decisions on the channel signal, compares the hard decisions to the channel signal to determine a noise level, and thereafter flags the channel output in regions with excessive noise levels.
    Type: Grant
    Filed: August 22, 1996
    Date of Patent: January 13, 1998
    Assignee: LSI Logic Corporation
    Inventors: Daniel A. Luthi, Ravi Bhaskaran, Dojun Rhee, Advait M. Mogre