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Location and tracking system

  • US 6,275,705 B1
  • Filed: 11/27/1998
  • Issued: 08/14/2001
  • Est. Priority Date: 12/22/1995
  • Status: Expired due to Term
First Claim
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1. A mobile radio-frequency communication system, comprising:

  • a network of at least two base stations arranged to transmit the same signals to at least one mobile radio-frequency transceiver, and receive signals from the one or more mobile radio-frequency transceivers;

    a reference receiver located at a fixed location a known distance from each of the base stations and including measuring means to measure the times of arrival of signals transmitted from the base stations;

    determination means to use the known distances and measured times to determine the relative time offsets of transmissions from each base station; and

    location means to use the determined relative time offsets to calculate the position of a mobile transceiver in the network area using techniques involving comparison of the times of arrival of signals from the base stations at the mobile transceiver;

    wherein the mobile transceiver calculates the impulse response of the channel and uses this information to reduce multi-path effects.

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