Patents by Inventor Changdon Kee

Changdon Kee 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: 8928529
    Abstract: This disclosure relates to a positioning system and a method based on a radio communication apparatus including multiple antennas, and more particularly, to a positioning system and a method of positioning a terminal using a communication apparatus including multiple antennas. The positioning system and the method based on a radio communication apparatus including multiple antennas calculate a position of a terminal using a single communication apparatus in which the multiple antennas are mounted and can calculate the position of the terminal more accurately by using two or more communication apparatuses. In addition, the positioning system and the method communicate with a transception apparatus, a relay station, or a wireless access point of an existing communication system, thereby accurately obtaining the position of the terminal.
    Type: Grant
    Filed: February 11, 2010
    Date of Patent: January 6, 2015
    Assignee: SNU R&DB Foundation
    Inventors: Changdon Kee, Taikjin Lee
  • Publication number: 20120218145
    Abstract: The pseudolite-based navigation system includes: a plurality of pseudolites for transmitting a navigation signal which simulates a satellite signal transmitted from a plurality of GNSS satellites; and a portable device capable of calculating a navigation solution for a location thereof based on the signal received from the pseudolites, wherein the portable device includes: a GNSS receiver for receiving the navigation signal of the pseudolites and calculating a navigation solution based on the navigation signal; and a computing unit for calculating a final navigation solution by integrating the navigation solution calculated by the GNSS receiver and the location information of the GNSS satellites and the pseudolites.
    Type: Application
    Filed: February 21, 2012
    Publication date: August 30, 2012
    Applicant: SNU R&DB FOUNDATION
    Inventors: Changdon KEE, Hyoungmin SO, Chongwon KIM
  • Publication number: 20120075145
    Abstract: This disclosure relates to a positioning system and a method based on a radio communication apparatus including multiple antennas, and more particularly, to a positioning system and a method of positioning a terminal using a communication apparatus including multiple antennas. The positioning system and the method based on a radio communication apparatus including multiple antennas calculate a position of a terminal using a single communication apparatus in which the multiple antennas are mounted and can calculate the position of the terminal more accurately by using two or more communication apparatuses. In addition, the positioning system and the method communicate with a transception apparatus, a relay station, or a wireless access point of an existing communication system, thereby accurately obtaining the position of the terminal.
    Type: Application
    Filed: February 11, 2010
    Publication date: March 29, 2012
    Applicant: SNU R&DB FOUNDATION
    Inventors: Changdon Kee, Taikjin Lee
  • Patent number: 5726659
    Abstract: Novel techniques are disclosed for eliminating multipath errors, including mean bias errors, in pseudorange measurements made by conventional global positioning system receivers. By correlating the multipath signals of different satellites at their cross-over points in the sky, multipath mean bias errors are effectively eliminated. By then taking advantage of the geometrical dependence of multipath, a linear combination of spherical harmonics are fit to the satellite multipath data to create a hemispherical model of the multipath. This calibration model can then be used to compensate for multipath in subsequent measurements and thereby obtain GPS positioning to centimeter accuracy.
    Type: Grant
    Filed: September 21, 1995
    Date of Patent: March 10, 1998
    Assignee: Stanford University
    Inventors: Changdon Kee, Bradford W. Parkinson