Patents by Inventor Karthik Khanna Subramani

Karthik Khanna Subramani 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: 20240097962
    Abstract: A receiver apparatus for receiving an OFDM radio signal comprising a first plurality of subcarrier-symbols, modulated on a corresponding plurality of subcarriers, and a second plurality of subcarrier-symbols, modulated on the corresponding plurality of subcarriers, to generate first and second bit sequences, the first bit sequence being an interleaved version of the second bit sequence according to a predetermined interleave function. Soft-output decoder logic generates a first soft-bit sequence for the first plurality of subcarrier-symbols, and a second soft-bit sequence for the second plurality of subcarrier-symbols. Combiner logic combines the soft-bit sequences, with the soft-bit sequences either both in an interleaved state or both in a non-interleaved state, by combining a respective soft-bit having a bit position in the first soft-bit sequence with a respective soft-bit having a same bit position in the second soft-bit sequence.
    Type: Application
    Filed: September 13, 2023
    Publication date: March 21, 2024
    Applicant: Nordic Semiconductor ASA
    Inventors: George VARGHESE, Karthik Khanna SUBRAMANI
  • Patent number: 9647867
    Abstract: A direct down-conversion (DDC) front end receiver includes first Q-channel that filters a sum of PRBS and baseband quadrature signals to generate a first filtered quadrature signal, a second Q-channel that filters a difference of the baseband and PRBS signals to generate a second filtered quadrature signal, a first I-channel and a second I-channel, Q-path and I-path PRBS cancellation blocks for cancelling corresponding PRBS components from sum of first and second filtered quadrature signals and sum of first and second filtered inphase signals respectively, Q-path and I-path sum filter estimation blocks for estimating quadrature and inphase sum filter responses. An IQ mismatch compensation filter estimate and tracking block estimates IQ mismatch compensation filter response from estimated quadrature and inphase sum filter responses, and an IQ mismatch compensation filter filters the modified inphase signal with the IQ mismatch compensation filter response, to generate a filter compensated inphase signal.
    Type: Grant
    Filed: December 8, 2015
    Date of Patent: May 9, 2017
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Karthik Khanna Subramani, Nagarajan Viswanathan, Avinash Vasudev Sakleshpur, Jaiganesh Balakrishnan
  • Publication number: 20160373288
    Abstract: A direct down-conversion (DDC) front end receiver includes first Q-channel that filters a sum of PRBS and baseband quadrature signals to generate a first filtered quadrature signal, a second Q-channel that filters a difference of the baseband and PRBS signals to generate a second filtered quadrature signal, a first I-channel and a second I-channel, Q-path and I-path PRBS cancellation blocks for cancelling corresponding PRBS components from sum of first and second filtered quadrature signals and sum of first and second filtered inphase signals respectively, Q-path and I-path sum filter estimation blocks for estimating quadrature and inphase sum filter responses. An IQ mismatch compensation filter estimate and tracking block estimates IQ mismatch compensation filter response from estimated quadrature and inphase sum filter responses, and an IQ mismatch compensation filter filters the modified inphase signal with the IQ mismatch compensation filter response, to generate a filter compensated inphase signal.
    Type: Application
    Filed: December 8, 2015
    Publication date: December 22, 2016
    Inventors: KARTHIK KHANNA SUBRAMANI, Nagarajan Viswanathan, Avinash Vasudev Sakleshpur, Jaiganesh Balakrishnan
  • Patent number: 9160358
    Abstract: A system can include a close-in tone control configured to detect a set of close-in tones of an interleaved analog to digital converter (IADC) signal and output a trigger signal in response to the detection. The system can also include a close-in tone mismatch estimator configured to determine a correlation and a power estimate for the set of close-in tones in the IADC signal in response to the trigger signal.
    Type: Grant
    Filed: March 12, 2015
    Date of Patent: October 13, 2015
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Sthanunathan Ramakrishnan, Jawaharlal Tangudu, Sashidharan Venkatraman, Karthik Khanna Subramani, Sreenath Narayanan Potty
  • Publication number: 20150263747
    Abstract: A system can include a close-in tone control configured to detect a set of close-in tones of an interleaved analog to digital converter (IADC) signal and output a trigger signal in response to the detection. The system can also include a close-in tone mismatch estimator configured to determine a correlation and a power estimate for the set of close-in tones in the IADC signal in response to the trigger signal.
    Type: Application
    Filed: March 12, 2015
    Publication date: September 17, 2015
    Inventors: Sthanunathan Ramakrishnan, Jawaharlal Tangudu, Sashidharan Venkatraman, Karthik Khanna Subramani, Sreenath Narayanan Potty