Patents by Inventor Andrew J. Macdonald

Andrew J. Macdonald 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: 5606569
    Abstract: A cellular base station receiver uses a digital signal processor to decode receiver code words in an inner Reed-Solomon code. A list of code word estimates is generated by making different symbol erasure combinations. An outer cyclic redundancy code operates as an error detector for the word estimates. When a code word estimate is found to be error-free, it is accepted for output.
    Type: Grant
    Filed: February 15, 1996
    Date of Patent: February 25, 1997
    Assignee: Hughes Electronics
    Inventors: Andrew J. MacDonald, Stanley E. Kay
  • Patent number: 5390197
    Abstract: A vestigial identification system is provided for transmitting information in a cellular communications network employing frequency reuse. The vestigial identification system enables a receiver to detect both bit errors and interfering messages to avoid call disruption. A composite parity check is produced by encoding message data and a site identifier via an encoder. A transmitter conveys a code word, formed at a code word generator by combining the composite parity check with the message data, to a receiver. At the receiver, an encoder forms an error detection parity check by encoding both the message data from the code word and the site identifier. An error detector compares the composite parity check from the transmitted code word to the error detection parity check, and generates an error if the parity checks are not identical to one another, enabling rejection of the message by the receiver.
    Type: Grant
    Filed: December 4, 1992
    Date of Patent: February 14, 1995
    Assignee: Hughes Aircraft Company
    Inventors: Andrew J. MacDonald, Youngky Kim, Stanley E. Kay
  • Patent number: 5365571
    Abstract: A cellular radio-telephone system has a plurality of cells each of which has S sectors. The cells are grouped into a plurality of clusters each of which has N adjoining cells. Each cell has a set of assigned system frequencies with respective frequency subsets assigned to its sectors so that N groups of co-channel cells exist with each co-channel cell group including one cell from each cluster having channel frequencies corresponding to those for its co-channel cell group. Respective base station antennas are located in the respective sectors of the respective cells, and each of the cell sectors has a plurality of subscriber station directional antennas disposed at predetermined locations within the sector for communication linkage with the associated base station antenna. The cells are generally formed in rows and columns and further are formed to provide a predetermined relative orientation pattern for co-channel cell sectors.
    Type: Grant
    Filed: May 24, 1993
    Date of Patent: November 15, 1994
    Assignee: Hughes Aircraft Company
    Inventors: Peter S. Rha, Stanley E. Kay, Andrew J. MacDonald
  • Patent number: 5005015
    Abstract: A system and method for detecting the state and thickness of water accumulation on a surface incorporates a plurality of spaced, thin, electrically resonant circuits bonded to the surface and a radio frequency transmitter for exciting the circuits to resonance. A receiver detects the resonant signal from each circuit, determines the resonant frequency and quality factor of the circuit and correlates that information with predetermined data representing changes in resonant frequency and quality factor as a function of liquid water and ice accretion to thereby establish the state and thickness of water overlaying the circuits.
    Type: Grant
    Filed: August 7, 1989
    Date of Patent: April 2, 1991
    Assignee: General Electric Company
    Inventors: Rudolph A. Dehn, Andrew J. Macdonald
  • Patent number: 4825348
    Abstract: A resonant power converter has a plurality of transformers, each having a primary winding and a secondary winding coupled thereto; the primary windings of all of the plurality of transformers are connected in series. The plurality of transformer secondary circuits are effectively connected in parallel, for current addition. a relatively small portion of the resonance capacitor is placed across each primary winding to insure a low impedance which causes the secondary-winding-connected rectifiers to commutatively switch substantially independently and share the entire output current substantially equally. A plurality of lower power transformers are thus utilized to replace a single high power transformer, so that leakage inductance is reduced and a higher operating frequency can be maintained.
    Type: Grant
    Filed: January 4, 1988
    Date of Patent: April 25, 1989
    Assignee: General Electric Company
    Inventors: Robert L. Steigerwald, Andrew J. Macdonald