Patents by Inventor Vijay Chellappa

Vijay Chellappa 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: 10348341
    Abstract: Systems and methods for providing indications about the TX RF non-linear impairments are disclosed. In accordance with some implementations, a first device (UE or base station) estimates EVM indications for the signal and determines if the EVM indications is above a threshold. The first device may transmit the estimated TX non-linearity indications math as AM-AM, AM-PM, Volterra coefficients, and/or other performance metrics to a second device, that transmitted the signal, when it is determined that the EVM indications is above the threshold. Systems and methods for wireless communication impairment correction are also disclosed wherein, in accordance with some implementations, a first device receives estimated TX non-linearity indications such as AM-AM, AM-PM, and/or Volterra coefficients from a second device and performs non-linear correction of a transmit signal for the second receiver device based at least in part on the EVM indications.
    Type: Grant
    Filed: March 29, 2018
    Date of Patent: July 9, 2019
    Assignee: QUALCOMM Incorporated
    Inventors: Haim Mendel Weissman, Igor Gutman, Joseph Patrick Burke, Vijay Chellappa, Sumit Verma, Paul Draxler
  • Publication number: 20180219566
    Abstract: Systems and methods for providing indications about the TX RF non-linear impairments are disclosed. In accordance with some implementations, a first device (UE or base station) estimates EVM indications for the signal and determines if the EVM indications is above a threshold. The first device may transmit the estimated TX non-linearity indications math as AM-AM, AM-PM, Volterra coefficients, and/or other performance metrics to a second device, that transmitted the signal, when it is determined that the EVM indications is above the threshold. Systems and methods for wireless communication impairment correction are also disclosed wherein, in accordance with some implementations, a first device receives estimated TX non-linearity indications such as AM-AM, AM-PM, and/or Volterra coefficients from a second device and performs non-linear correction of a transmit signal for the second receiver device based at least in part on the EVM indications.
    Type: Application
    Filed: March 29, 2018
    Publication date: August 2, 2018
    Inventors: Haim Mendel Weissman, Igor Gutman, Joseph Patrick Burke, Vijay Chellappa, Sumit Verma, Paul Draxler
  • Publication number: 20180124716
    Abstract: A radio frequency (RF) system including: a modem configured to generate a first set of digital bits and to create an analog RF signal from those digital bits; a power amplifier configured to receive the analog RF signal and to amplify the analog RF signal, the power amplifier including an input for a biasing voltage; a feedback loop configured to sample an output of the power amplifier, generate a second set of digital bits corresponding to the first set of digital bits, digitally process the second set of digital bits to determine a linearity characteristic of the power amplifier, and to adjust the biasing voltage in response to determining the linearity characteristic.
    Type: Application
    Filed: March 29, 2017
    Publication date: May 3, 2018
    Inventors: Sudarsan Krishnan, Andrei Izotov, Carl Hardin, Vijay Chellappa, Li Gao
  • Patent number: 9960794
    Abstract: Systems and methods for providing indications about the TX RF non-linear impairments are disclosed. In accordance with some implementations, a first device (UE or base station) estimates EVM indications for the signal and determines if the EVM indications is above a threshold. The first device may transmit the estimated TX non-linearity indications such as AM-AM, AM-PM, Volterra coefficients, and/or other performance metrics to a second device, that transmitted the signal, when it is determined that the EVM indications is above the threshold. Systems and methods for wireless communication impairment correction are also disclosed wherein, in accordance with some implementations, a first device receives estimated TX non-linearity indications such as AM-AM, AM-PM, and/or Volterra coefficients from a second device and performs non-linear correction of a transmit signal for the second receiver device based at least in part on the EVM indications.
    Type: Grant
    Filed: September 23, 2016
    Date of Patent: May 1, 2018
    Assignee: QUALCOMM Incorporated
    Inventors: Haim Mendel Weissman, Igor Gutman, Joseph Patrick Burke, Vijay Chellappa, Sumit Verma, Paul Draxler
  • Publication number: 20170366209
    Abstract: Systems and methods for providing indications about the TX RF non-linear impairments are disclosed. In accordance with some implementations, a first device (UE or base station) estimates EVM indications for the signal and determines if the EVM indications is above a threshold. The first device may transmit the estimated TX non-linearity indications such as AM-AM, AM-PM, Volterra coefficients, and/or other performance metrics to a second device, that transmitted the signal, when it is determined that the EVM indications is above the threshold. Systems and methods for wireless communication impairment correction are also disclosed wherein, in accordance with some implementations, a first device receives estimated TX non-linearity indications such as AM-AM, AM-PM, and/or Volterra coefficients from a second device and performs non-linear correction of a transmit signal for the second receiver device based at least in part on the EVM indications.
    Type: Application
    Filed: September 23, 2016
    Publication date: December 21, 2017
    Inventors: Haim Mendel Weissman, Igor Gutman, Joseph Patrick Burke, Vijay Chellappa, Sumit Verma, Paul Draxler
  • Patent number: 9762274
    Abstract: An apparatus includes an elliptical inductance-capacitance (LC) filter and a resistive-capacitive (RC) notch filter serially coupled to the elliptical LC filter. The elliptical LC filter and the RC notch filter are configured to filter a radio-frequency (RF) signal received by a feedback receive path.
    Type: Grant
    Filed: March 20, 2015
    Date of Patent: September 12, 2017
    Assignee: QUALCOMM Incorporated
    Inventors: Shailesh Shekhar Rai, Mahim Ranjan, Jeremy Mark Goldblatt, Frederic Bossu, Vijay Chellappa
  • Publication number: 20160080119
    Abstract: A method and apparatus for self-testing a GSM/EDGE communications device. An embodiment provides a method of measuring transmit power. A receive phase locked loop (PLL) is inserted into a feedback receiver local oscillator mixer. The receive PLL is then tuned to a local oscillator frequency. Once the tuning is complete, an I and a Q signal are captured using a channel of the feedback receiver. After capture, a I2+Q2 sum is computed, measuring the transmit power. The feedback receiver automatic gain control (AGC) may be used to determine transmit power in place of I2+Q2. The apparatus includes: a modem assembly, a power control assembly, a power amplifier, a duplexer, a coupler and a switch. The power control assembly further includes a first PLL and first and second mixers. The second mixer is connected to a feedback low noise amplifier and receives input from a feedback receiver PLL.
    Type: Application
    Filed: September 12, 2014
    Publication date: March 17, 2016
    Inventors: Rema Vaidyanathan, Prasad Srinivasa Siva Gudem, Vijay Chellappa, Chalin Chac Lee, Li Gao, David Coronel
  • Publication number: 20150349821
    Abstract: An apparatus includes an elliptical inductance-capacitance (LC) filter and a resistive-capacitive (RC) notch filter serially coupled to the elliptical LC filter. The elliptical LC filter and the RC notch filter are configured to filter a radio-frequency (RF) signal received by a feedback receive path.
    Type: Application
    Filed: March 20, 2015
    Publication date: December 3, 2015
    Inventors: Shailesh Shekhar Rai, Mahim Ranjan, Jeremy Mark Goldblatt, Frederic Bossu, Vijay Chellappa