Patents by Inventor Yifeng Zhang

Yifeng Zhang 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: 20110159835
    Abstract: Systems and methods of clock generation for radio frequency receiver. In radio frequency receiver, the system requires accurate local oscillating (LO) signal and system clocks for proper operation and to ensure high quality performance. In order to achieve accurate LO frequency and system clock, a crystal or and accurate reference clock is provide to the clock generation circuit. How a low-cost receiver, it is desirable to eliminate the requirement for a crystal or an accurate reference clock. The present invention discloses systems and methods to utilize a pilot signal embedded in the transmitted signal. The pilot signal usually has very accurate frequency which is particular true for broadcast system such as FM broadcast. In various embodiments of the present invention, the systems and methods measure the relation between the frequency of the pilot signal and the current clock generated.
    Type: Application
    Filed: December 30, 2009
    Publication date: June 30, 2011
    Applicant: Quintic Holdings
    Inventors: Peiqi Xuan, Yifeng Zhang
  • Publication number: 20110151483
    Abstract: The present invention provides isolated nucleic acid and amino acid sequences of sweet or amino acid taste receptors comprising T1R3 and T1R1, two heterologous G-protein coupled receptor polypeptides from the T1R family of sensory G-protein coupled receptors, antibodies to such receptors, methods of detecting such nucleic acids and receptors, and methods of screening for modulators of sweet and amino acid taste receptors.
    Type: Application
    Filed: November 11, 2010
    Publication date: June 23, 2011
    Inventors: Charles S. Zuker, Jayaram Chandrashekar, Greg Nelson, Yifeng Zhang, Nicholas J. P. Ryba, Mark A. Hoon
  • Publication number: 20110053534
    Abstract: Systems of clock generation for integrated radio frequency receiver. In an integrated radio frequency receiver, a mixer is often used to down convert the incoming radio frequency signal. The down converted signal is then digitized and digital signal processing circuitry is used for efficient and flexible implementation of various functions to receive the underlying audio and/or data information. The mixer requires clock generation circuitry to provide a proper local oscillator signal for a selected channel. On the other hand, the digital signal processing circuitry requires its separate digital clock for proper operations. The clock generation system utilizes single local oscillator generation circuitry to provide the local oscillator signals required by the mixer and the digital clock signals required by the digital signal processing circuitry.
    Type: Application
    Filed: September 1, 2009
    Publication date: March 3, 2011
    Applicant: QUINTIC HOLDINGS
    Inventors: Peiqi Xuan, Yifeng Zhang, Xuechu Li
  • Publication number: 20110034139
    Abstract: Systems and method for automatic adjustment of tunable filter for portable radio frequency receivers. The effective antenna impedance for a portable radio frequency receiver is often affected by human body. The front end tunable filter may become off tuned due to human body effect. The system relies on radio frequency signals received from an antenna interface and utilizes receive path circuitry to derive signal parameters about the received signal. Tuning control circuitry is used to provide control signals based on the signal parameters to adjust the tunable filter to achieve the best receiver performance. A method is disclosed for automatic adjustment of the tunable filter.
    Type: Application
    Filed: August 4, 2009
    Publication date: February 10, 2011
    Applicant: QUINTIC HOLDINGS
    Inventors: Peiqi Xuan, Yifeng Zhang
  • Patent number: 7842786
    Abstract: The present invention provides isolated nucleic acid and amino acid sequences of sweet or amino acid taste receptors comprising T1R3 and T1R1, two heterologous G-protein coupled receptor polypeptides from the T1R family of sensory G-protein coupled receptors, antibodies to such receptors, methods of detecting such nucleic acids and receptors, and methods of screening for modulators of sweet and amino acid taste receptors.
    Type: Grant
    Filed: May 15, 2008
    Date of Patent: November 30, 2010
    Assignees: Regents of the University of California, United States of America, NIH
    Inventors: Charles S Zuker, Nicholas J. P. Ryba, Jayaram Chandrashekar, Mark A Hoon, Yifeng Zhang, Gregory A Nelson
  • Publication number: 20100067629
    Abstract: In one embodiment, a TFI-OFDM receiver system (22) is able to more reliably decode the information bits by estimating the noise variance associated with the channel and using these estimates in mitigating in-band interference. In another embodiment, there is a TFI-OFDM receiver system (66) that is able to update the estimated channel impulse response and the noise variance by generating reference OFDM symbols from the received header symbols, the band hopping pattern provided by the TFC number associated with the communication link, the estimated channel impulse response and the noise variance estimates and symbols generated from a FFT processor (30).
    Type: Application
    Filed: November 28, 2007
    Publication date: March 18, 2010
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS, N.V.
    Inventors: Vasanth R. Gaddam, Tianyan Pu, Yifeng Zhang
  • Patent number: 7647069
    Abstract: A transmitter and/or receiver includes a single crystal clock oscillator circuit and a sample rate converter (SRC) that selectively generates samples at an alternative frequency for subsequent transmission or decoding. A 40 MHz crystal provides the clock signal for the digital-to-analog and analog-to-digital converters that are used to convert the samples to and from analog form. In an IEEE 802.11-compatible embodiment, the 802.11a compatible 20 MHz OFDM samples are converted to and from analog form directly, whereas a sample rate converter converts the 802.11b compatible 22 MHz DSSS samples to and from 40 MHz samples to provide compatibility with the 40 MHz analog conversions.
    Type: Grant
    Filed: October 25, 2002
    Date of Patent: January 12, 2010
    Assignee: NXP B.V.
    Inventor: Yifeng Zhang
  • Publication number: 20100002679
    Abstract: A wireless device (400) receives a beacon frame. Using the carrier frequency information included in the beacon frame, a frequency offset value between the wireless device (400) and the wireless host (500) is determined. Based on the frequency offset value, a clock drift value between the host clock (504) in the wireless host (500) and the local clock (406) in the wireless device (400) is determined. The wireless device (400) is then powered up in preparation for receiving a subsequent beacon frame based on the clock drift value between the host clock (504) in the wireless host (500) and the local clock (406) in the wireless device (400).
    Type: Application
    Filed: September 19, 2006
    Publication date: January 7, 2010
    Applicant: NXP BV
    Inventors: Yifeng Zhang, Robbert Emery
  • Publication number: 20090311982
    Abstract: A scan system receives signals within a band from an antenna and divides the band into sub-bands and scans the channels of each sub-band to determine a candidate channel based on the lowest figure of merit (FOM) and includes an on-channel selection block responsive to a received digital signal and operative to select only the on-channel frequencies and to substantially disregard the out-of-channel frequencies from the digital signal. The scan system generates a FOM on-channel signal representing a measurement of the signal quality of the on-channel signal and includes an out-of-channel selection block responsive to the digital signal and operative to select only the out-of-channel frequencies and to substantially disregard the on-channel frequencies from the digital signal and operative to generate a FOM out-of-channel signal representing a measurement of the signal quality of the out-of-channel signal.
    Type: Application
    Filed: June 11, 2008
    Publication date: December 17, 2009
    Inventors: Yifeng ZHANG, Tracey Lee CHAVERS, Peiqi XUAN, Qifa WU
  • Publication number: 20090310803
    Abstract: A method of the present invention includes coordinating tuning to the same channel of a radio band wherein the following steps are performed: tuning to a channel, within a radio band, that uses a side band; receiving control information in the side band of the channel; and processing the received audio information in the channel using the control information.
    Type: Application
    Filed: July 11, 2008
    Publication date: December 17, 2009
    Applicant: Quintic Holdings
    Inventors: Yifeng ZHANG, Kou-Hu TZOU, Pengyi HONG, Hangwei GUO
  • Publication number: 20090310786
    Abstract: Systems for audio and data transmission in a broadcast band are disclosed. The system comprises a channel condition assessment module at the transmit side to identify an un-occupied or empty channel to transmit. The system also comprises a means to achieve automatic channel coordination between the transmit side and the receive side. Further, the transmit side includes a digital interface module and the receive side includes a digital output interface module configured to control an embedding electronic device. Means for enhancing audio privacy and digital data rate are also disclosed.
    Type: Application
    Filed: June 30, 2009
    Publication date: December 17, 2009
    Applicant: QUINTIC HOLDINGS
    Inventors: Yifeng Zhang, Victor Ren, Bo Xia
  • Publication number: 20090311973
    Abstract: FM radio transmitter is being widely used in portable devices as a convenient way to output audio contents to ubiquitously available FM radio receivers in cars or homes. However, the signal from the FM radio transmitter may be interfering with the signal being broadcast by an FM radio station. A scan system is incorporated into the FM radio transmitter to quickly and reliably identify a vacant channel for the FM radio transmitter to use. The scan system measures on-channel and out-of-channel signal quality and selects a best channel for transmission based on the measured on-channel and out-of-channel signal quality. The scan system is also incorporated into an FM radio receiver to quickly and reliably tune to a valid channel. The scan system selects the valid channel based on the measured on-channel and out-of-channel signal quality.
    Type: Application
    Filed: May 28, 2009
    Publication date: December 17, 2009
    Applicant: QUINTIC HOLDINGS
    Inventors: Yifeng Zhang, Tracey Lee Chavers, Peiqi Xuan, Qifa Wu
  • Publication number: 20090243690
    Abstract: In an embodiment of the present invention, a clock generator circuit is disclosed to include a phase locked loop (PLL) that is responsive to a clock signal quadrature output frequency and a clock signal in-phase output frequency. The clock generator circuit generates a single clock frequency that is a fraction of the frequency of the clock signal quadrature output frequency and the clock signal in-phase output frequency. The PLL includes a single voltage controlled oscillator (VCO) that generates the single clock frequency. A plurality of dividers is included in the clock generator circuit and is responsive to the clock signal quadrature output frequency and the clock signal in-phase output frequency and generates multiple clock frequencies, each clock frequency being a unique frequency, each of the plurality of dividers generating an output that is phase and frequency synchronized to the single clock frequency.
    Type: Application
    Filed: March 3, 2008
    Publication date: October 1, 2009
    Applicant: QUINTIC HOLDINGS
    Inventors: Yifeng ZHANG, Peiqi XUAN, Kanyu CAO, Xiaodong JIN
  • Patent number: 7588900
    Abstract: The present invention provides isolated nucleic acid and amino acid sequences of sweet or amino acid taste receptors comprising two heterologous G-protein coupled receptor polypeptides from the T1R family of sensory G-protein coupled receptors, antibodies to such receptors, methods of detecting such nucleic acids and receptors, and methods of screening for modulators of sweet and amino acid taste receptors.
    Type: Grant
    Filed: July 3, 2002
    Date of Patent: September 15, 2009
    Assignees: The Regents of the University of California, The United States of America as represented by the Secretary of the Department of Health and Human Services
    Inventors: Charles S Zuker, Nicholas J. P. Ryba, Jayaram Chandrashekar, Mark A Hoon, Yifeng Zhang, Greg Nelson
  • Patent number: 7555051
    Abstract: A quadrature transmitter and receiver have configurable I and Q channel paths that facilitate the application of selected test signals to determine gain and phase imbalances introduced by the transmitter and receiver. In a first ‘normal’ configuration, the I and Q channels are independently tested by applying an I-only test signal, followed by a Q-only test signal. In a second ‘switched transmitter’ configuration, the Q-only test signal is again applied. In a third ‘switched receiver’ configuration, the I-only test signal is again applied. By combining the results, gain and phase imbalances of the transmitter and the receiver can be determined. In a preferred embodiment, these configurations and test signals are applied within a single transceiver that has the output of its transmitter closed-loop coupled to the input of its receiver.
    Type: Grant
    Filed: May 28, 2004
    Date of Patent: June 30, 2009
    Assignee: NXP B.V.
    Inventor: Yifeng Zhang
  • Publication number: 20090098580
    Abstract: The present invention provides isolated nucleic acid and amino acid sequences of sweet taste receptors comprising two heterologous G-protein coupled receptor polypeptides from the T1R family of sensory G-protein coupled receptors, antibodies to such receptors, methods of detecting such nucleic acids and receptors, and methods of screening for modulators of sweet taste receptors.
    Type: Application
    Filed: June 26, 2008
    Publication date: April 16, 2009
    Inventors: Charles S. Zuker, Nicholas J.P. Ryba, Gregory A. Nelson, Mark A. Hoon, Jayaram Chandrashekar, Yifeng Zhang
  • Patent number: 7507793
    Abstract: The present invention provides isolated nucleic acid and amino acid sequences of sweet taste receptors comprising two heterologous G-protein coupled receptor polypeptides from the T1R family of sensory G-protein coupled receptors, antibodies to such receptors, methods of detecting such nucleic acids and receptors, and methods of screening for modulators of sweet taste receptors.
    Type: Grant
    Filed: August 20, 2003
    Date of Patent: March 24, 2009
    Assignees: The Regents of the University of California, United States of America Dept. of Health and Human Services National Institutes of Health-OTT
    Inventors: Charles S. Zuker, Nicholas J. P. Ryba, Gregory A. Nelson, Mark A. Hoon, Jayaram Chandrashekar, Yifeng Zhang
  • Publication number: 20090041134
    Abstract: Systems and methods according to the present invention provide channel estimation methods, systems and devices which determine a coarse channel estimate (40) and a fine channel estimate (66). The coarse channel (40) estimate can be determined based on the channel estimation sequence transmitted to the receiver and then used to detect header symbols. The header symbols can be used to calculate additional channel estimates which can then be combined with the coarse channel estimate (40) to determine a fine channel estimate (66).
    Type: Application
    Filed: August 26, 2005
    Publication date: February 12, 2009
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.
    Inventor: Yifeng Zhang
  • Publication number: 20080318251
    Abstract: The present invention provides isolated nucleic acid and amino acid sequences of sweet or amino acid taste receptors comprising two heterologous G-protein coupled receptor polypeptides from the T1R family of sensory G-protein coupled receptors, antibodies to such receptors, methods of detecting such nucleic acids and receptors, and methods of screening for modulators of sweet and amino acid taste receptors.
    Type: Application
    Filed: May 15, 2008
    Publication date: December 25, 2008
    Inventors: Charles S. Zuker, Jayaram Chandrashekar, Greg Nelson, Yifeng Zhang, Nicholas J.P. Ryba, Mark A. Hoon
  • Publication number: 20080279169
    Abstract: Systems and methods according to the present invention provide methods for wireless communications and devices associated therewith which vary the intermediate frequency based upon the particular channel and/or system with which a wireless station is communicating. Tailoring the selection of an intermediate frequency in this way, enables signal energy associated with images created by heterodyne processing to be more easily removed.
    Type: Application
    Filed: August 26, 2005
    Publication date: November 13, 2008
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.
    Inventor: Yifeng Zhang