Patents by Inventor Alan G. Cha

Alan G. Cha 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).

  • Micro cell architecture for mobile user tracking communication system
    Patent number: 6914557
    Abstract: A system and method for tracking a user. The system is adapted for use in a wireless communication system and creates a plurality of beams within a coverage area. A first beam is directed at a user in a first microcell and a number of additional beams illuminate microcells immediately adjacent the first microcell. The system is equipped with a mechanism for detecting movement of the user from the first microcell to one of the immediately adjacent microcells. On the detection of movement of the user, the system redirects the first beam from the first microcell to a second microcell, the second microcell being one of the adjacent microcells. In the illustrative embodiment, the system is implemented in a stratospheric platform based communication system including a hub adapted to communicate with a stratospheric platform. A transceiver and a phased array antenna are disposed on the platform to communicate with the hub and with the user. A second antenna is provided on the platform to communicate with the hub.
    Type: Grant
    Filed: September 5, 2001
    Date of Patent: July 5, 2005
    Assignee: The DIRECTV Group, Inc.
    Inventors: Donald C. D. Chang, Ying Feria, Weizheng Wang, Alan G. Cha, Ming U. Chang, Frank A. Hagen, Kar W. Yung