Patents by Inventor Vijay K. Chellappa
Vijay K. 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).
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Patent number: 9154243Abstract: Techniques for calibrating a receiver based on a local oscillator (LO) signal from another receiver are disclosed. In an exemplary design, an apparatus (e.g., a wireless device or an integrated circuit) includes first and second local oscillator (LO) generators. The first LO generator generates a first LO signal used by a first receiver for frequency downconversion. The second LO generator generates a second LO signal used by a second receiver for frequency downconversion in a first operating mode. The second LO signal is used to generate a test signal for the first receiver in a second operating mode. The second LO signal may be provided as the test signal or may be amplitude modulated with a modulating signal to generate the test signal. The test signal may be used to calibrate residual sideband (RSB), second order input intercept point (IIP2), receive path gain, etc.Type: GrantFiled: February 26, 2013Date of Patent: October 6, 2015Assignee: QUALCOMM IncorporatedInventors: Udara C. Fernando, Li-Chung Chang, Vijay K. Chellappa, Frederic Bossu, Ketan Humnabadkar, Gurkanwal Singh Sahota
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Patent number: 9137757Abstract: A wireless communication device includes: an antenna for receiving inbound signals on dual receive channels and transmitting outbound signals on dual transmit channels; a transceiver coupled to the antenna to receive the inbound signals from the antenna and convey the outbound signals; a power controller coupled to the transceiver to control power levels of the outbound signals so a maximum nominal power level of the outbound signals is a first power level; and a processor coupled to the transceiver and the antenna to cause the power controller to control the power levels of the outbound signals so if a power level of a received one of the inbound signals is below a threshold value, then the maximum nominal power level of the outbound signals is a second power level lower than the first power level, wherein the second power level is lower than the first power level.Type: GrantFiled: February 9, 2011Date of Patent: September 15, 2015Assignee: QUALCOMM IncorporatedInventors: Heechoon Lee, Sharad Deepak Sambhwani, Wesley A. Sampson, Harris S. Simon, Vijay K. Chellappa, Danlu Zhang
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Patent number: 9041464Abstract: Circuitry for reducing power consumption is described. The circuitry includes a power amplifier. The circuitry also includes a predistorter coupled to the power amplifier. The circuitry further includes a power supply coupled to the power amplifier. The circuitry additionally includes a controller coupled to the power amplifier, to the predistorter and to the power supply. The controller captures a transmit signal and a feedback signal concurrently and determines a minimum bias voltage from a set of voltages and a predistortion that enable the power amplifier to produce an amplified transmit signal in accordance with a requirement.Type: GrantFiled: September 13, 2012Date of Patent: May 26, 2015Assignee: QUALCOMM IncorporatedInventors: Christos Komninakis, Vijay K. Chellappa, Jifeng Geng
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Patent number: 9031158Abstract: A method and apparatus for providing total power from one transmit path. The method provides the steps of: selecting a transmit path and closing a first switch, located after a digital to analog converter. A second switch between the two transmit paths is then closed in order to provide for the use of at least one low-pass filter in each transmit path. The signal is then processed through the at least one low pass filter in each transmit path. The signal is then processed through at least one mixer in each transmit path. After the mixer, the signal is then processed through at least one driver amplifier in each transmit path, and one-half of the total power is allocated to each of two transmission paths. A third switch is then closed after the at least one power amplifier in each transmit path to force the half-power from one transmit path into one output.Type: GrantFiled: October 8, 2012Date of Patent: May 12, 2015Assignee: QUALCOMM IncorporatedInventors: Prasad Srinivasa Siva Gudem, Vijay K Chellappa, Jeremy Darren Dunworth, Chiewcharn Narathong
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Publication number: 20140171001Abstract: Techniques for calibrating a receiver based on a local oscillator (LO) signal from another receiver are disclosed. In an exemplary design, an apparatus (e.g., a wireless device or an integrated circuit) includes first and second local oscillator (LO) generators. The first LO generator generates a first LO signal used by a first receiver for frequency downconversion. The second LO generator generates a second LO signal used by a second receiver for frequency downconversion in a first operating mode. The second LO signal is used to generate a test signal for the first receiver in a second operating mode. The second LO signal may be provided as the test signal or may be amplitude modulated with a modulating signal to generate the test signal. The test signal may be used to calibrate residual sideband (RSB), second order input intercept point (IIP2), receive path gain, etc.Type: ApplicationFiled: February 26, 2013Publication date: June 19, 2014Applicant: QUALCOMM INCORPORATEDInventors: Udara C. Fernando, Li-Chung Chang, Vijay K. Chellappa, Frederic Bossu, Ketan Humnabadkar, Gurkanwal Singh Sahota
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Patent number: 8755456Abstract: A wireless device for waveform scaling is disclosed. The wireless device includes a modulator that increases a magnitude of a peak digital code beyond a maximum available digital code for transmit power levels below a transmit power threshold to produce an adjusted digital code. The magnitude of the peak digital code is not increased beyond the maximum available digital code for transmit power levels above the transmit power threshold. The wireless device also includes a digital-to-analog converter that converts the adjusted digital code into an analog signal.Type: GrantFiled: March 8, 2012Date of Patent: June 17, 2014Assignee: QUALCOMM IncorporatedInventors: Vinod V. Panikkath, Vijay K. Chellappa, Bhushan Shanti Asuri
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Patent number: 8754706Abstract: A power train amplification stage is described. The power train amplification stage includes a power amplifier. The power train amplification stage also includes a switched mode power supply that provides a bias voltage to the power amplifier. The power train amplification stage further includes a pulse density modulator. The power train amplification stage also includes a feedback path from the power amplifier to the pulse density modulator.Type: GrantFiled: June 7, 2012Date of Patent: June 17, 2014Assignee: QUALCOMM IncorporatedInventors: Prasad Srinivasa Siva Gudem, Ketan Humnabadkar, Vijay K. Chellappa, Sumit Verma
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Publication number: 20140098906Abstract: A method and apparatus for providing total power from one transmit path. The method provides the steps of: selecting a transmit path and closing a first switch, located after a digital to analog converter. A second switch between the two transmit paths is then closed in order to provide for the use of at least one low-pass filter in each transmit path. The signal is then processed through the at least one low pass filter in each transmit path. The signal is then processed through at least one mixer in each transmit path. After the mixer, the signal is then processed through at least one driver amplifier in each transmit path, and one-half of the total power is allocated to each of two transmission paths. A third switch is then closed after the at least one power amplifier in each transmit path to force the half-power from one transmit path into one output.Type: ApplicationFiled: October 8, 2012Publication date: April 10, 2014Applicant: QUALCOMM INCORPORATEDInventors: Prasad Srinivasa Siva Gudem, Vijay K Chellappa, Jeremy Darren Dunworth, Chiewcharn Narathong
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Publication number: 20130257529Abstract: Circuitry for reducing power consumption is described. The circuitry includes a power amplifier. The circuitry also includes a predistorter coupled to the power amplifier. The circuitry further includes a power supply coupled to the power amplifier. The circuitry additionally includes a controller coupled to the power amplifier, to the predistorter and to the power supply. The controller captures a transmit signal and a feedback signal concurrently and determines a minimum bias voltage from a set of voltages and a predistortion that enable the power amplifier to produce an amplified transmit signal in accordance with a requirement.Type: ApplicationFiled: September 13, 2012Publication date: October 3, 2013Applicant: QUALCOMM INCORPORATEDInventors: Christos Komninakis, Vijay K. Chellappa, Jifeng Geng
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Publication number: 20130033314Abstract: A power train amplification stage is described. The power train amplification stage includes a power amplifier. The power train amplification stage also includes a switched mode power supply that provides a bias voltage to the power amplifier. The power train amplification stage further includes a pulse density modulator. The power train amplification stage also includes a feedback path from the power amplifier to the pulse density modulator.Type: ApplicationFiled: June 7, 2012Publication date: February 7, 2013Applicant: QUALCOMM INCORPORATEDInventors: Prasad Srinivasa Siva Gudem, Ketan Humnabadkar, Vijay K. Chellappa, Sumit Verma
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Publication number: 20120315961Abstract: A wireless communication device for deriving a dynamic voltage scaling data profile is described. The wireless communication device includes memory that includes a dynamic voltage scaling voice profile. The wireless communication device also includes a data profile determination module coupled to the memory. The data profile determination module obtains an offset and derives a dynamic voltage scaling data profile by offsetting the dynamic voltage scaling voice profile based on the offset.Type: ApplicationFiled: May 23, 2012Publication date: December 13, 2012Applicant: QUALCOMM INCORPORATEDInventors: Mei Chen, Vijay K. Chellappa, Sumit Verma, Ketan Humnabadkar, Bhaskar Natarajakumar, Carl Thomas Hardin
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Patent number: 8275331Abstract: Techniques for optimizing the power consumption of existing low cost multi-gain state power amplifiers (PA) to increase the talk time of wireless communication devices are described. In an exemplary embodiment a device, such as a baseband processor, operates to set a multistage PA having at least two gain states for amplifying a transmit signal to a lowest power consuming gain state. The device calculates a transition power level as a function of an identified maximum power reduction (MPR) value and switches the PA to a higher gain state from a lower gain state when a transmission power level is higher than the calculated transition power level.Type: GrantFiled: December 4, 2009Date of Patent: September 25, 2012Assignee: QUALCOMM, IncorporatedInventors: Sumit Verma, Vijay K. Chellappa, Gurkanwal S. Sahota
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Publication number: 20120230447Abstract: A wireless device for waveform scaling is disclosed. The wireless device includes a modulator that increases a magnitude of a peak digital code beyond a maximum available digital code for transmit power levels below a transmit power threshold to produce an adjusted digital code. The magnitude of the peak digital code is not increased beyond the maximum available digital code for transmit power levels above the transmit power threshold. The wireless device also includes a digital-to-analog converter that converts the adjusted digital code into an analog signal.Type: ApplicationFiled: March 8, 2012Publication date: September 13, 2012Applicant: QUALCOMM IncorporatedInventors: Vinod V. Panikkath, Vijay K. Chellappa, Bhushan Shanti Asuri
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Publication number: 20110199949Abstract: A wireless communication device includes: an antenna for receiving inbound signals on dual receive channels and transmitting outbound signals on dual transmit channels; a transceiver coupled to the antenna to receive the inbound signals from the antenna and convey the outbound signals; a power controller coupled to the transceiver to control power levels of the outbound signals so a maximum nominal power level of the outbound signals is a first power level; and a processor coupled to the transceiver and the antenna to cause the power controller to control the power levels of the outbound signals so if a power level of a received one of the inbound signals is below a threshold value, then the maximum nominal power level of the outbound signals is a second power level lower than the first power level, wherein the second power level is lower than the first power level.Type: ApplicationFiled: February 9, 2011Publication date: August 18, 2011Applicant: QUALCOMM IncorporatedInventors: Heechoon Lee, Sharad Deepak Sambhwani, Wesley A. Sampson, Harris S. Simon, Vijay K. Chellappa, Danlu Zhang
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Publication number: 20110141930Abstract: A method for compensating for phase discontinuities on a communication device is described. A communication device may determine a desired output power. The communication device may determine a Digital-to-Analog Converter (DAC) gain corresponding to the desired output power. The communication device may determine a cumulative phase offset based on the DAC gain. The communication device may apply the DAC gain. The communication device may apply a phase compensation to a rotator to adjust for the cumulative phase offset.Type: ApplicationFiled: August 27, 2010Publication date: June 16, 2011Applicant: QUALCOMM INCORPORATEDInventors: Sumit Verma, Vijay K. Chellappa, Bhushan Shanti Asuri
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Publication number: 20100308909Abstract: Techniques for optimizing the power consumption of existing low cost multi-gain state power amplifiers (PA) to increase the talk time of wireless communication devices are described. In an exemplary embodiment a device, such as a baseband processor, operates to set a multistage PA having at least two gain states for amplifying a transmit signal to a lowest power consuming gain state. The device calculates a transition power level as a function of an identified maximum power reduction (MPR) value and switches the PA to a higher gain state from a lower gain state when a transmission power level is higher than the calculated transition power level.Type: ApplicationFiled: December 4, 2009Publication date: December 9, 2010Applicant: QUALCOMM IncorporatedInventors: Sumit Verma, Vijay K. Chellappa, Gurkanwal S. Sahota