Patents by Inventor Charles Sobchak

Charles Sobchak 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: 20070086547
    Abstract: An automatic gain control (AGC) system for a receiver and corresponding method facilitate AGC in a receiver. The automatic gain control system includes an on-channel signal detector 123 configured to provide an on-channel signal level indication corresponding to a narrow band on-channel signal and a wideband signal detector 121 configured to provide a wideband signal level indication corresponding to a wideband signal, where the wideband signal includes the narrow band on-channel signal. Further included is a controller 149 that is coupled to the wideband signal level indication and the on-channel signal level indication and that is configured to provide a gain control signal corresponding to the wideband signal level and one or more of a plurality of states of the receiver.
    Type: Application
    Filed: October 18, 2005
    Publication date: April 19, 2007
    Inventors: Charles Sobchak, Mahibur Rahman
  • Publication number: 20060280268
    Abstract: Methods (1500) and corresponding systems (400, 500) for determining and correcting a DC offset in a receiver operate to sample (1503) a signal to provide complex samples; estimate (1505) a Direct Current (DC) offset corresponding to each of the complex samples, the estimating the DC offset further including solving a plurality of equations relating to the plurality of complex samples, e.g., N simultaneous equations in N samples with a power of the signal invariant across the N samples, to deterministically derive offset values; and then remove (1517) the DC offset from the signal.
    Type: Application
    Filed: June 14, 2005
    Publication date: December 14, 2006
    Inventors: Charles Sobchak, Mahibur Rahman
  • Publication number: 20060223463
    Abstract: Dynamic gain and phase compensation is provided in a radio frequency (RF) receiver (106) including at least one switched Low Noise Amplifier (LNA) (212) coupled to an RF gain control unit (226) providing a gain control signal to the at least one switched LNA (212) for control thereof. The RF receiver also includes an analog-to-digital (A/D) converter (222) for digitizing the RF signal and outputting an N-bit digital signal to the RF gain control unit (226). The method for gain compensation includes dynamically adjusting the N-bit digital signal to compensate for the at least one switched LNA (212) in response to the gain control signal. The method for phase compensation includes dynamically normalizing the N-bit digital signal into an M-bit signal range to derive an M-bit digital signal, where M?N and dynamically phase adjusting the M-bit digital signal to compensate for the at least one switched LNA (212) in response to the gain control signal.
    Type: Application
    Filed: April 4, 2005
    Publication date: October 5, 2006
    Inventors: Mahibur Rahman, Charles Sobchak, James Hughes
  • Publication number: 20060222117
    Abstract: A method and apparatus are provided for providing improved radio frequency (RF) receiver signal correction. For RF receiver circuitry (106) having receive path and a warmup period associated therewith and including at least one analog baseband gain control stage (218) having a gain associated therewith, the method includes the step of performing a DC correction calculation operation during the warmup period to derive a DC correction value having a first component and a second component for each of the at least one gain control stage (218). The DC correction calculation step includes the steps of performing a first closed loop correction (460) of a baseband path to derive the first component of the DC correction value and performing a second closed loop correction (462) of the receive path as a function of the (218) gain during the warmup period to derive the second component of the DC correction value.
    Type: Application
    Filed: April 4, 2005
    Publication date: October 5, 2006
    Inventors: Mahibur Rahman, Manish Shah, Charles Sobchak
  • Publication number: 20050190867
    Abstract: A narrowband interference cancellation system, method and digital signal processor is disclosed that removes narrowband interference in wide band communication systems. The system includes a narrowband processing component, wideband processing component, soft metric generator and at least one filter. The system is configured to receive a signal, identify one or more narrowband interferers in the received signal and filter out identified narrowband interferers. The narrowband processing component includes a filter bank configured to separate the received signal into a predetermined number of channel bands and identify a band with interference. The wide band processing component provides an average level for an unfiltered version of the received signal. The soft decision metric generator produces metrics based on predetermined thresholds.
    Type: Application
    Filed: March 1, 2004
    Publication date: September 1, 2005
    Inventors: Charles Sobchak, Mahibur Rahman, David Haub, Louis Vannatta