Patents by Inventor Zae Yong Choi

Zae Yong Choi 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: 8594155
    Abstract: Systems and methodologies are described that facilitate synthesizing a single baseband waveform from digital signals related to multiple carriers. Digital signals can be received relating to a plurality of carriers. The digital signals can result from spreading data symbols from transport blocks to create chip sequences, which can additionally be pulse shaped. The digital signals can be rotated in a positive or negative direction, such as according to a complex sinusoid or a negative representation thereof. The rotated signals can be combined or added to generate a single baseband waveform. The single baseband waveform can be converted to an analog signal, which can be up-converted and centered at a plurality of frequency carriers, which can be adjacent, assigned for transmitting the signal. In addition, optimizations can be provided to ensure threshold power ratio over the plurality of carriers for effectively transmitting jointly encoded signals.
    Type: Grant
    Filed: January 4, 2010
    Date of Patent: November 26, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Sharad D. Sambhwani, Zae Yong Choi, Heechoon Lee, Arjun Bharadwaj
  • Patent number: 8170819
    Abstract: A method for measuring non-linear characteristics of a power amplifier is described. A calibration waveform is calculated during a testing procedure period. Amplitude characteristics of the calibration waveform at the output of the power amplifier are measured during the testing procedure period. Phase characteristics of the calibration waveform at the output of the power amplifier are measured during the testing procedure period. Pre-distortion techniques are configured based on the amplitude characteristics and the phase characteristics to be used during a normal operation period of a transmitter.
    Type: Grant
    Filed: April 23, 2008
    Date of Patent: May 1, 2012
    Assignee: QUALCOMM, Incorporated
    Inventors: Revathi Sundara Raghavan, Puay Hoe See, Rema Vaidyanathan, Richard M. Schierbeck, II, Sudarsan Krishnan, Zae Yong Choi
  • Patent number: 8059748
    Abstract: Transmitters supporting multiple modulation modes and/or multiple frequency bands are described. A transmitter may perform large signal polar modulation, small signal polar modulation, and/or quadrature modulation, which may support different modulation schemes and systems. Circuit blocks may be shared by the different modulation modes to reduce cost and power. For example, a single modulator and a single power amplifier may be used for small signal polar modulation and quadrature modulation. The transmitter may apply pre-distortion to improve performance, to allow a power amplifier to support multiple frequency bands, to allow the power amplifier to operate at higher output power levels, etc. Envelope and phase distortions due to non-linearity of the power amplifier may be characterized for different input levels and different bands and stored at the transmitter.
    Type: Grant
    Filed: September 19, 2007
    Date of Patent: November 15, 2011
    Assignee: QUALCOMM, Incorporated
    Inventors: Puay Hoe See, Gurkanwal Singh Sahota, Bo Sun, Gary John Ballantyne, William Ronald Panton, Zae Yong Choi
  • Publication number: 20100172395
    Abstract: Systems and methodologies are described that facilitate synthesizing a single baseband waveform from digital signals related to multiple carriers. Digital signals can be received relating to a plurality of carriers. The digital signals can result from spreading data symbols from transport blocks to create chip sequences, which can additionally be pulse shaped. The digital signals can be rotated in a positive or negative direction, such as according to a complex sinusoid or a negative representation thereof. The rotated signals can be combined or added to generate a single baseband waveform. The single baseband waveform can be converted to an analog signal, which can be up-converted and centered at a plurality of frequency carriers, which can be adjacent, assigned for transmitting the signal. In addition, optimizations can be provided to ensure threshold power ratio over the plurality of carriers for effectively transmitting jointly encoded signals.
    Type: Application
    Filed: January 4, 2010
    Publication date: July 8, 2010
    Applicant: QUALCOMM, Incorporated
    Inventors: Sharad D. Sambhwani, Zae Yong Choi, Heechoon Lee, Arjun Bharadwaj
  • Publication number: 20090138226
    Abstract: A method for measuring non-linear characteristics of a power amplifier is described. A calibration waveform is calculated during a testing procedure period. Amplitude characteristics of the calibration waveform at the output of the power amplifier are measured during the testing procedure period. Phase characteristics of the calibration waveform at the output of the power amplifier are measured during the testing procedure period. Pre-distortion techniques are configured based on the amplitude characteristics and the phase characteristics to be used during a normal operation period of a transmitter.
    Type: Application
    Filed: April 23, 2008
    Publication date: May 28, 2009
    Applicant: QUALCOMM INCORPORATED
    Inventors: Revathi Sundara Raghavan, Puay Hoe See, Rema Vaidyanathan, Richard M. Schierbeck, II, Sudarsan Krishnan, Zae Yong Choi
  • Publication number: 20090074106
    Abstract: Transmitters supporting multiple modulation modes and/or multiple frequency bands are described. A transmitter may perform large signal polar modulation, small signal polar modulation, and/or quadrature modulation, which may support different modulation schemes and systems. Circuit blocks may be shared by the different modulation modes to reduce cost and power. For example, a single modulator and a single power amplifier may be used for small signal polar modulation and quadrature modulation. The transmitter may apply pre-distortion to improve performance, to allow a power amplifier to support multiple frequency bands, to allow the power amplifier to operate at higher output power levels, etc. Envelope and phase distortions due to non-linearity of the power amplifier may be characterized for different input levels and different bands and stored at the transmitter.
    Type: Application
    Filed: September 19, 2007
    Publication date: March 19, 2009
    Applicant: QUALCOMM INCORPORATED
    Inventors: Puay Hoe See, Gurkanwal Singh Sahota, Bo Sun, Gary John Ballantyne, William Ronald Panton, Zae Yong Choi