Patents by Inventor Chien-Cheng Tung

Chien-Cheng Tung 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: 7248650
    Abstract: A coding/decoding trellis structure circuit included in a maximum likelihood sequence estimator (MLSE) sub-receiver having one or more distance calculation units (distus) responsive to equalized data generated by said MLSE sub-receiver from wireless transmission of transmitted data, said distu further responsive to MLSE codewords for processing the same, said equalized data including one or more equalized data chips and each of said MLSE codewords including one or more MLSE codeword chips, each of said distus for processing an equalized data chip and an MLSE codeword chip to generate a chip output, said distu for using said chip output to generate distance measures, a distance measure being the distance between said equalized data and said MLSE codeword, in accordance with an embodiment of the present invention.
    Type: Grant
    Filed: June 4, 2003
    Date of Patent: July 24, 2007
    Assignee: Ralink Technology, Inc.
    Inventors: Chien-Cheng Tung, Julian Chih Liang Chang
  • Patent number: 7197094
    Abstract: A maximum likelihood sequence estimator (MLSE) sub-receiver is disclosed, in one embodiment of the present invention and includes an MLSE equalizer device responsive to input data to generate equalized data. The input data is generated from transmitted data by wireless transmission. The MLSE equalizer device processes the input data to generate residual channel response using a known codebook and the residual channel response to generate an MLSE codebook. The MLSE sub-receiver further includes an MLSE decoder responsive to the equalized data and the MLSE codebook for processing to determine maximum likelihood between the equalized data and the MLSE codebook. The MLSE decoder uses the maximum likelihood for decoding the equalized data to generate a decoded transmitted data by mitigating the effects of multi-path communication channel due to wireless transmission of the transmitted data.
    Type: Grant
    Filed: March 28, 2003
    Date of Patent: March 27, 2007
    Assignee: Ralink Technology, Inc.
    Inventor: Chien-Cheng Tung
  • Patent number: 6687344
    Abstract: A computer having a modem is programmed with software (also called a “on-hook/off-hook detector”) that detects a change in status (e.g., on-hook or off-hook) of a device (e.g., a telephone having a handset) by measuring a change in the signal power of a signal flowing through a telephone line connecting the modem and the device. In particular, the computer programmed with the on-hook/off-hook detector detects a status of a telephone handset by measuring power of a reference signal and measuring power of an instantaneous signal on the connection and comparing these two measurements. The reference signal is a constant signal whose power does not change. Then, the computer programmed with the on-hook/off-hook detector is able to detect whether there has been a change in status of the telephone handset by comparing the detected status with a previous status of the telephone handset.
    Type: Grant
    Filed: September 7, 2001
    Date of Patent: February 3, 2004
    Assignee: PCTEL,Inx.
    Inventors: Chien-Cheng Tung, XiaoHua Luo, Anthony L. Mazzarini
  • Publication number: 20030231709
    Abstract: A maximum likelihood sequence estimator (MLSE) equalizer device being included in an MLSE sub-receiver includes a feedforward circuit responsive to input data for processing the same to generate feedforward circuit output, said input data being generated from transmitted data being transmitted by wireless transmission, in accordance with an embodiment of the present invention. The MLSE equalizer device further includes a feedback circuit responsive to said input data for processing the same to generate feedback circuit output.
    Type: Application
    Filed: March 28, 2003
    Publication date: December 18, 2003
    Inventors: Thomas Edward Pare, Chien-Cheng Tung, Cedric Choi
  • Publication number: 20030231722
    Abstract: A maximum likelihood sequence estimator (MLSE) sub-receiver having an MLSE equalizer device responsive to input data for processing the same to generate equalized data, said input data being generated from transmitted data by wireless transmission, said MLSE equalizer device processing said input data to generate residual channel response, said MLSE equalizer device using a known codebook and said residual channel response to generate an MLSE codebook, in accordance with an embodiment of the invention. The MLSE sub-receiver further includes an MLSE decoder responsive to said equalized data and said MLSE codebook for processing the same to determine maximum likelihood between said equalized data and said MLSE codebook, said MLSE decoder using said maximum likelihood for decoding said equalized data to generate a decoded transmitted data by mitigating the effects of multi-path communication channel due to wireless transmission of said transmitted data.
    Type: Application
    Filed: March 28, 2003
    Publication date: December 18, 2003
    Inventor: Chien-Cheng Tung
  • Publication number: 20030065830
    Abstract: A computer automatically measures one or more parameters (also called “observable parameters”; examples include number being dialed and line probing result), and the computer uses the measurements to identify a set of values of parameters (also called “controllable parameters”; examples include equalizer coefficients, echo canceller coefficients, and disabling of V.8bis/Kflex) from non-volatile memory, for use in a current connection. The values of controllable parameters in each set may have been saved in non-volatile memory while operating the modem in a previous connection, or may be default values set by the factory, for example. Use of a previously saved set of controllable parameter values to operate a modem during a current connection, saves time otherwise required to independently generate a set of values each time the modem is operated and increases modem performance.
    Type: Application
    Filed: January 31, 2002
    Publication date: April 3, 2003
    Inventors: Chien-Cheng Tung, Thomas Paul, Zhengjin Shu, Gary A. Anwyl, Derek Obata
  • Patent number: 6512787
    Abstract: Short pseudo-random (PR) probing sequences that comply with ITU V.90 digital impairment learning (DIL) descriptors provide DIL probing sequences that yield high performance in severe inter-symbol interference (ISI) channels. The short PR sequences do not require the insertion of extra zero symbols to get rid of ISI. Further, a novel receiving structure corrects for propagation of digital impairment common in conventional equalizers for an ISI free receipt of the probing sequences within the strictly time constrained probing sequence. Based on the reliably received signals, general digital impairment mapping tables, digital pads, regular and strange RBS patterns, and different types of PCM codecs (A-law/&mgr;-law) are identified.
    Type: Grant
    Filed: April 23, 1999
    Date of Patent: January 28, 2003
    Assignee: PC-Tel, Inc.
    Inventors: Chien-Cheng Tung, Di Zhou