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CDMA communications and geolocation system and method

  • US 5,974,039 A
  • Filed: 06/09/1997
  • Issued: 10/26/1999
  • Est. Priority Date: 12/05/1990
  • Status: Expired due to Fees
First Claim
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1. A spread-spectrum communications and geolocation method for communicating message data, comprising the steps of:

  • generating, at a base station, a base-generic-chip-code signal;

    spread-spectrum processing the message data with a message-chip-code signal as a spread-spectrum-processed-message data;

    combining the base-generic-chip-code signal with the spread-spectrum-processed-message data, thereby generating a base-code-division-multiple-access (CDMA) signal;

    transmitting, using radio waves traversing free space, the base-CDMA signal from a transmitter over a communications channel;

    detecting, from the communications channel at a remote unit, the base-generic-chip-code signal embedded in the base-CDMA signal;

    recovering, using the detected-base-generic-chip-code signal, the message data embedded in the base-CDMA signal;

    relaying the detected-base-generic-chip-code signal as a remote-generic-chip-code signal;

    spread-spectrum processing remote-message data with a remote-chip-code signal as a spread-spectrum-processed-remote-message data;

    combining the spread-spectrum-processed-remote-message data with the remote-generic-chip-code signal as a remote-CDMA signal;

    transmitting the remote-CDMA signal over the communications channel to the base station;

    detecting, at the base station, the remote-generic-chip-code signal embedded in the remote-CDMA signal; and

    recovering, using the detected-remote-generic-chip-code signal, the remote-message data embedded in the remote-CDMA signal.

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