Patents by Inventor Shou Y. Mui

Shou Y. Mui 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: 7596323
    Abstract: A method and apparatus for estimating fiber dispersion in an optical communication system including transmitting an optical signal carrying a unique word along an optical communication path, receiving the optical signal carrying the unique word from the optical communication path, producing an electrical signal corresponding to the received unique word, and processing the electrical signal corresponding to the received unique word to produce an estimate of the fiber dispersion in the optical communication system.
    Type: Grant
    Filed: January 4, 2006
    Date of Patent: September 29, 2009
    Assignee: Broadwing Corporation
    Inventors: Alistair J. Price, Bassel F. Beidas, Terry L. Bittner, A. Roger Hammons, Jr., William M. Kirschner, Daniel F. McAlister, Shou Y. Mui
  • Patent number: 5432819
    Abstract: A data receiver receives differential phase-shift keyed (DPSK) signals, and filters the signal by a process including frequency conversion, under the control of an estimated carrier frequency (f.sub.re), to produce a filtered output signal which is applied to a DPSK demodulator. The filtering compensates for the Doppler frequency errors, and reduces the phase error. The estimated frequency is determined by second and third controllable filters, which filter the DPSK carrier signal at frequencies above and below the estimated carrier frequency by an offset frequency which depends on the data rate. A first frequency error estimate is made in a processor coupled to the second and third filters, from the ratio of the amplitudes of the first and second filter output signals. A second-order tracking loop is coupled to the processor for averaging the frequency error estimate over a predetermined number of bits, to generate the estimate of the carrier frequency.
    Type: Grant
    Filed: March 9, 1994
    Date of Patent: July 11, 1995
    Assignee: Martin Marietta Corporation
    Inventor: Shou Y. Mui
  • Patent number: 5425058
    Abstract: An MSK receiver includes a downconverter for downconverting the received MSK signals. The phase drift or phase error per bit of the message preamble is determined. The reference carriers are generated, and the phase of the reference signals is adjusted during message demodulation under the control of the estimated rate of phase change across the preamble portion. In accordance with another aspect of the invention, the downconverted MSK signal burst is digitized and the digitized burst signal is stored in memory, following which it is read repeatedly so that bit timing, start-of-message timing, carrier phase, and carrier drift processing may be performed in a desired sequence, using all the available information for more accurate demodulation. According to a yet further aspect of the invention, a second order tracking loop is used to adjust the phase of the demodulation reference signals.
    Type: Grant
    Filed: July 28, 1993
    Date of Patent: June 13, 1995
    Assignee: Martin Marietta Corporation
    Inventor: Shou Y. Mui
  • Patent number: 5150378
    Abstract: A method for using coherent modulation and coding to improve the error-rate of non-coherent frequency-hopping data transmission systems includes aiding phase estimation by sending, in each hop, one or more reference bits, which are known to the receiver, and using the reference bits along with the data bits received in that same hop to estimate the channel phase. The data bits are then demodulated using the estimaated phase. The method also uses weighting of the demodulator output during each hop by a factor expressing the confidence level for the correctness of the phase estimated for that hop. Apparatus for implementing my novel methodology is also provided.
    Type: Grant
    Filed: October 7, 1991
    Date of Patent: September 22, 1992
    Assignee: General Electric Company
    Inventor: Shou Y. Mui
  • Patent number: 4694467
    Abstract: A modem in which the transmitter uses spectrum spreading techniques applied to sequentially supplied input bits, a first group thereof having one spread spectrum sequence characteristic and a second group thereof having a different spread spectrum sequence characteristic, the spread spectrum bits being modulated and transmitted. The receiver generates complex samples of the received modulated signal at a baseband frequency and uses a detector for providing signal samples of the complex samples which are time delayed relative to each other. A selected number of the time delayed samples are de-spread and demodulated and the de-spread and demodulated samples are then combined to form a demodulated receiver output signal.
    Type: Grant
    Filed: July 3, 1986
    Date of Patent: September 15, 1987
    Assignee: Signatron, Inc.
    Inventor: Shou Y. Mui
  • Patent number: 4547887
    Abstract: A method and apparatus for interleaving and deinterleaving psuedo-randomly a digital signal which is transmitted over a transmission channel is disclosed. A received bit stream is interleaved such that the order of the bits is varied in a non-random manner. The order of the interleaved bits is permutated in a pseudo-random manner and the bits are then transmitted over a transmission channel. The received bits are inverse permuted so as to return the order of the received bits to the order of the bits after the non-random interleaving step. The inverse permuted bits are then deinterleaved in the reverse order in which they were interleaved so as to reconstitute the original bit stream.
    Type: Grant
    Filed: November 30, 1983
    Date of Patent: October 15, 1985
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Shou Y. Mui