Patents by Inventor Juncheng C. Liu

Juncheng C. Liu 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: 7613229
    Abstract: A method of managing fingers for multipath signals in a wireless communication device. In one embodiment, the present invention recites receiving multipath signals at a wireless communication device. The present embodiment then acquires one of the multipath signals in a searcher portion of the wireless communication device and determines a signal-to-noise ratio (SNR) level of the one multipath signal. Next, the present embodiment evaluates the multipath signal for categorization into one of a plurality of states and then generates a finger assignment by selectively providing the multipath signal for a demodulation operation based upon its state. The present embodiment then receives the finger assignment from the searcher portion of the communication device and determines a signal-strength for the finger assignment. The present embodiment then enables the finger assignment for a combine operation if the signal-strength for the finger assignment satiates a first signal-strength threshold.
    Type: Grant
    Filed: October 2, 2000
    Date of Patent: November 3, 2009
    Assignee: ST Wireless SA
    Inventors: Luis Aldaz, Gibong Jeong, Daniel Jeng Hsia, Juncheng C. Liu, Greg Luker
  • Patent number: 7403507
    Abstract: A sleep control system and method are provided that permit a reference clock and the direct sequence spread spectrum (DSSS) modem in a mobile station receiver to be turned off and turned back on at arbitrary points in time while still maintaining accurate base station system time. Accurate timing is made possible through a number of techniques including precise initial calibration using a rising edge/falling edge averaging system, determining the sleep clock and reference clock frequencies, and the determination of the frequency drift of the sleep clock that occurred during the previous sleep interval.
    Type: Grant
    Filed: June 18, 2001
    Date of Patent: July 22, 2008
    Assignee: Texas Instruments Incorporated
    Inventors: John G. McDonough, Juncheng C. Liu, Yan Hui, Chunhao Chen
  • Patent number: 6725016
    Abstract: A method for managing multipath signals to be demodulated by a receiver with multiple demodulators. The method includes a series of steps, including receiving the multipath signals at a wireless communication receiver device, finding the multipath signals having sufficient signal strength for demodulation, and measuring an arrival time of one of the multipath signals. In one embodiment, the present invention also recites measuring a signal-to-noise ratio (SNR) level of one of the multipath signals, updating a multipath list with the arrival time and the signal-to-noise ratio if the multipath signal is identified based upon the arrival time with one of the multipath signals existing in the multipath list, and identifying newly-found multipath signals and evaluating one of the newly-found multipath signals based on the signal-to-noise ratio for categorization into one of a plurality of states.
    Type: Grant
    Filed: October 2, 2000
    Date of Patent: April 20, 2004
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Gibong Jeong, Luis Aldaz, Daniel Jeng Hsia, Juncheng C. Liu, Greg Luker
  • Publication number: 20030043766
    Abstract: A sleep control system and method are provided that permit a reference clock and the direct sequence spread spectrum (DSSS) modem in a mobile station receiver to be turned off and turned back on at arbitrary points in time while still maintaining accurate base station system time. Accurate timing is made possible through a number of techniques including precise initial calibration using a rising edge/falling edge averaging system, determining the sleep clock and reference clock frequencies, and the determination of the frequency drift of the sleep clock that occurred during the previous sleep interval.
    Type: Application
    Filed: June 18, 2001
    Publication date: March 6, 2003
    Inventors: John G. McDonough, Juncheng C. Liu, Yan Hui, Chunhao Chen
  • Publication number: 20030002566
    Abstract: A system and method for shifting the phase of a PN code sequence are provided, useful in communications networks where power can be conserved by powering-off the PN clock and PN generators during slotted mode sleep intervals. The system and method targets a family of time intervals, and stores phase shifting masks corresponding to these probable intervals. The PN code generated with the phase-shifting mask at power-up is sufficiently accurate to permit rapid resynchronization. Further, because the phase-shifting masks do not have to be calculated, processing time is minimized and the PN clock and generators can be powered-off for longer periods of time.
    Type: Application
    Filed: June 19, 2001
    Publication date: January 2, 2003
    Inventors: John G. McDonough, Juncheng C. Liu
  • Patent number: 6356581
    Abstract: An apparatus and method thereof for sampling multipath signal data in a receiver. The apparatus includes a plurality of demodulators coupled in parallel, each of the plurality of demodulators receiving digital baseband signal data and demodulating the digital baseband signal data, a controller coupled to the plurality of demodulators, and a timer coupled to the controller. The timer generates a controller interrupt at a specified frequency. The controller interrupt causes the controller to sample demodulated signal data from the plurality of demodulators. The specified frequency is greater than the symbol rate.
    Type: Grant
    Filed: May 28, 1999
    Date of Patent: March 12, 2002
    Assignees: Philips Electronics North American Corporation, Texas Instruments Incorporated
    Inventors: Tien Nguyen, John McDonough, Juncheng C. Liu