Patents by Inventor Nikhil A. Deshmukh

Nikhil A. Deshmukh 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: 8948320
    Abstract: A system and method for performing frame and symbol timing synchronization on samples of a received signal that includes a series of frames. Each frame includes a known preamble and payload data. A start-of-frame time is estimated by scanning the received signal samples for the self similarity of two successive preambles. A carrier frequency offset (CFO) is estimated by maximizing a correlation between a magnitude spectrum of the received signal and a magnitude spectrum of a known preamble model. A fine estimate for the CFO is determined by computing a phase difference between samples separated by p repetitions of the base pattern for various values of index p, and computing a slope of a least squares affine fit to the phase differences. Additional operations are performed to find an optimal symbol starting point, to perform carrier phase synchronization and to detect the start of payload data.
    Type: Grant
    Filed: December 23, 2013
    Date of Patent: February 3, 2015
    Assignee: National Instruments Corporation
    Inventors: Baijayanta Ray, Nikhil A. Deshmukh
  • Publication number: 20140105342
    Abstract: A system and method for performing frame and symbol timing synchronization on samples of a received signal that includes a series of frames. Each frame includes a known preamble and payload data. A start-of-frame time is estimated by scanning the received signal samples for the self similarity of two successive preambles. A carrier frequency offset (CFO) is estimated by maximizing a correlation between a magnitude spectrum of the received signal and a magnitude spectrum of a known preamble model. A fine estimate for the CFO is determined by computing a phase difference between samples separated by p repetitions of the base pattern for various values of index p, and computing a slope of a least squares affine fit to the phase differences. Additional operations are performed to find an optimal symbol starting point, to perform carrier phase synchronization and to detect the start of payload data.
    Type: Application
    Filed: December 23, 2013
    Publication date: April 17, 2014
    Applicant: NATIONAL INSTRUMENTS CORPORATION
    Inventors: Baijayanta Ray, Nikhil A. Deshmukh
  • Patent number: 8634453
    Abstract: A system and method for performing frame and symbol timing synchronization on samples of a received signal that includes a series of frames. Each frame includes a known preamble and payload data. A start-of-frame time is estimated by scanning the received signal samples for the self similarity of two successive preambles. A carrier frequency offset (CFO) is estimated by maximizing a correlation between a magnitude spectrum of the received signal and a magnitude spectrum of a known preamble model. A fine estimate for the CFO is determined by computing a phase difference between samples separated by p repetitions of the base pattern for various values of index p, and computing a slope of a least squares affine fit to the phase differences. Additional operations are performed to find an optimal symbol starting point, to perform carrier phase synchronization and to detect the start of payload data.
    Type: Grant
    Filed: March 4, 2011
    Date of Patent: January 21, 2014
    Assignee: National Intruments Corporation
    Inventors: Baijayanta Ray, Nikhil A. Deshmukh
  • Patent number: 8238458
    Abstract: System and method for evaluating a transmitter by estimating IQ impairments in an orthogonal frequency division multiplexed (OFDM) signal generated by the transmitter. The OFDM signal may be received. The OFDM signal may represent a stream of symbols, each comprising a plurality of subcarriers. At least a subset of the subcarriers may be pilot subcarriers. The pilot subcarriers may be grouped into one or more groups of pilot subcarriers based on one or more conditions: a pilot subcarrier which satisfies a condition in its relation to a mirror subcarrier may be grouped with other pilot subcarriers which also satisfy the condition in relation to mirror subcarriers. An estimate of one or more of gain imbalance or quadrature skew of the OFDM signal may be calculated based on the one or more groups of pilot subcarriers and the one or more conditions. The estimate may be used to evaluate the transmitter.
    Type: Grant
    Filed: January 8, 2010
    Date of Patent: August 7, 2012
    Assignee: National Instruments Corporation
    Inventors: Prakash Sethia, Ramesh Krishnan, Nikhil Deshmukh
  • Publication number: 20120027147
    Abstract: A system and method for performing frame and symbol timing synchronization on samples of a received signal that includes a series of frames. Each frame includes a known preamble and payload data. A start-of-frame time is estimated by scanning the received signal samples for the self similarity of two successive preambles. A carrier frequency offset (CFO) is estimated by maximizing a correlation between a magnitude spectrum of the received signal and a magnitude spectrum of a known preamble model. A fine estimate for the CFO is determined by computing a phase difference between samples separated by p repetitions of the base pattern for various values of index p, and computing a slope of a least squares affine fit to the phase differences. Additional operations are performed to find an optimal symbol starting point, to perform carrier phase synchronization and to detect the start of payload data.
    Type: Application
    Filed: March 4, 2011
    Publication date: February 2, 2012
    Inventors: Baijayanta Ray, Nikhil A. Deshmukh
  • Publication number: 20110103496
    Abstract: System and method for evaluating a transmitter by estimating IQ impairments in an orthogonal frequency division multiplexed (OFDM) signal generated by the transmitter. The OFDM signal may be received. The OFDM signal may represent a stream of symbols, each comprising a plurality of subcarriers. At least a subset of the subcarriers may be pilot subcarriers. The pilot subcarriers may be grouped into one or more groups of pilot subcarriers based on one or more conditions: a pilot subcarrier which satisfies a condition in its relation to a mirror subcarrier may be grouped with other pilot subcarriers which also satisfy the condition in relation to mirror subcarriers. An estimate of one or more of gain imbalance or quadrature skew of the OFDM signal may be calculated based on the one or more groups of pilot subcarriers and the one or more conditions. The estimate may be used to evaluate the transmitter.
    Type: Application
    Filed: January 8, 2010
    Publication date: May 5, 2011
    Inventors: Prakash Sethia, Ramesh Krishnan, Nikhil Deshmukh