Patents by Inventor John Christopher Clarke

John Christopher Clarke 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: 7508883
    Abstract: The present invention sets out to overcome the hearability problem in CDMA communications networks in which positioning services are provided, by using a separate sampling device 204, 205, 206 for each transmitter 201, 202, 203, which sends to the computing device 208 a representation of the signals transmitted only by that transmitter. A cross-correlation of the representation sent back by the mobile terminal 207 with the representation sent back by the sampling device in the brightest transmitter is performed in the computing device 208, and a blurred estimate of that brightest signal is subtracted from a blurred version of the representation sent back by the mobile terminal 207 in order to reduce its effect on the remaining signals as far as possible. The cross-correlation and subtraction steps are iterated until no useful signals remain to be extracted.
    Type: Grant
    Filed: May 13, 2003
    Date of Patent: March 24, 2009
    Assignee: Cambridge Positioning Systems Limited
    Inventors: Peter James Duffett-Smith, Malcolm David Macnaughtan, John Christopher Clarke, Robert Willem Rowe
  • Patent number: 7260407
    Abstract: A location measurement unit 401 for a radio location measuring system has two or more coupling devices 404,405 for picking up the signals from a plurality of base transceiver stations (BTSs) of a cellular radio communication system. A switching device 510, is connected to the coupling devices, for switching between the signals picked up by the coupling devices and/or one/two or more receivers 510, 610-613 are connected to respective coupling devices, for receiving the signals picked up by the coupling devices. A processor 512, 614 is connected to the or each receiver, for processing the signals output by the receiver. A communications link 513, 615 is connected to the processor, for transferring the processed signals to a calculation node 514.
    Type: Grant
    Filed: April 18, 2002
    Date of Patent: August 21, 2007
    Assignee: Cambridge Positioning Systems Ltd.
    Inventors: Peter James Duffett-Smith, James Paul Brice, John Christopher Clarke
  • Patent number: 6894644
    Abstract: The present invention sets out to overcome the hearability problem in CDMA communications networks in which positioning services are provided, by using a separate sampling device (204, 205, 206) for each transmitter (201, 202, 203), which sends to the computing device (208) a representation of the signals transmitted only by that transmitter. A cross-correlation of the representation sent back by the mobile terminal (207) with the representation sent back by the sampling device in the brightest transmitter is performed in the computing device (208), and an estimate of that brightest signal is subtracted from the representation sent back by the mobile terminal (207) in order to reduce its effect on the remaining signals as far as possible. The cross-correlation and subtraction steps are iterated until no useful signals remain to be extracted.
    Type: Grant
    Filed: July 15, 2002
    Date of Patent: May 17, 2005
    Assignee: Cambridge Positioning Systems Limited
    Inventors: Peter James Duffett-Smith, Malcolm David MacNaughtan, John Christopher Clarke, Robert Willem Rowe
  • Publication number: 20040196186
    Abstract: The present invention sets out to overcome the hearability problem in CDMA communications networks in which positioning services are provided, by using a separate sampling device (204, 205, 206) for each transmitter (201, 202, 203), which sends to the computing device (208) a representation of the signals transmitted only by that transmitter. A cross-correlation of the representation sent back by the mobile terminal (207) with the representation sent back by the sampling device in the brightest transmitter is performed in the computing device (208), and an estimate of that brightest signal is subtracted from the representation sent back by the mobile terminal (207) in order to reduce its effect on the remaining signals as far as possible. The cross-correlation and subtraction steps are iterated until no useful signals remain to be extracted.
    Type: Application
    Filed: January 13, 2004
    Publication date: October 7, 2004
    Inventors: Peter James Duffett-Smith, Malcolm David MacNaughtan, John Christopher Clarke, Robert Willem Rowe
  • Publication number: 20040097241
    Abstract: A location measurement unit (401) for a radio location measuring system has two or more coupling devices (404, 405) for picking up the signals from a plurality of base transceiver stations (BTSs) of a cellular radio communication system. A switching device (510), is connected to the coupling devices, for switching between the signals picked up by the coupling devices and/or ne/two or more receivers (510, 610-613) are connected to respective coupling devices, for receiving the signals picked up by the coupling devices. A processor (512, 614) is connected to the or each receiver, for processing the signals output by the receiver. A communications link (513, 615) is connected to the processor, for transferring the processed signals to a calculation node (514).
    Type: Application
    Filed: October 29, 2003
    Publication date: May 20, 2004
    Inventors: Peter James Duffet-Smith, James Paul Brice, John Christopher Clarke