RFID location systems and methods
First Claim
1. A system for locating radio frequency identification (RFID) tags comprising:
- a plurality of RFID readers comprising first, second, and third RFID readers, each RFID reader comprising;
an RFID transmitter; and
an RFID receiver;
the first RFID reader configured to transmit a single radio frequency (RF) signal at a particular time from the RFID transmitter of the first RFID reader to a tag to be located;
each of the first, second, and third RFID readers configured to receive, at their corresponding RFID receiver, a signal backscattered off the tag from the single RF signal transmitted by the first RFID reader;
each of the first, second, and third RFID readers further configured to extract at least one measured position parameter from said signal backscattered off the tag and received at the first, second, and third RFID readers; and
at least one RFID reader in the plurality of the RFID readers further configured to determine a location of the tag using said measured position parameters extracted from the signal backscattered off the tag from the single RF signal transmitted at the particular time from the first RFID reader, wherein all measured position parameters used in determining the location of the tag are extracted from said signal backscattered off the tag from said single transmission at said particular time from the first RFID reader.
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Accused Products
Abstract
A system for locating RFID tags includes several RFID readers. A first RFID reader transmits a single RF signal at a particular time to a tag to be located. Each of the RFID readers receives a signal backscattered off the tag from the single RF signal that is transmitted by the first RFID reader. Each of the RFID readers extracts at least one measured position parameter from the signal backscattered off the tag. At least one RFID reader determines the location of the tag by using the measured position parameters extracted from the signal backscattered off the tag from the single RF signal transmitted at the particular time from the first RFID reader. All measured position parameters used in determining the location of the tag are extracted from the signal backscattered off the tag from the single transmission at the particular time from the first RFID reader.
81 Citations
22 Claims
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1. A system for locating radio frequency identification (RFID) tags comprising:
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a plurality of RFID readers comprising first, second, and third RFID readers, each RFID reader comprising; an RFID transmitter; and an RFID receiver; the first RFID reader configured to transmit a single radio frequency (RF) signal at a particular time from the RFID transmitter of the first RFID reader to a tag to be located; each of the first, second, and third RFID readers configured to receive, at their corresponding RFID receiver, a signal backscattered off the tag from the single RF signal transmitted by the first RFID reader; each of the first, second, and third RFID readers further configured to extract at least one measured position parameter from said signal backscattered off the tag and received at the first, second, and third RFID readers; and at least one RFID reader in the plurality of the RFID readers further configured to determine a location of the tag using said measured position parameters extracted from the signal backscattered off the tag from the single RF signal transmitted at the particular time from the first RFID reader, wherein all measured position parameters used in determining the location of the tag are extracted from said signal backscattered off the tag from said single transmission at said particular time from the first RFID reader. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A system for locating radio frequency identification (RFID) tags, the system comprising:
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a plurality of RFID readers comprising first, second, and third RFID readers, each RFID reader comprising; an RFID transmitter; and an RFID receiver; the first RFID reader configured to transmit a single radio frequency (RF) signal at a particular time from the first RFID reader to a tag to be located; each of the first, second, and third RFID readers configured to receive a signal backscattered off the tag from the single RF signal transmitted by the first RFID reader, each of the first, second, and third RFID readers including a clock synchronized to a same clock reference for measuring time, wherein time of arrival information based on the clocks is used to calculate a distance to the tag; each of the first, second, and third RFID readers further configured to extract at least one measured position parameter from the signal backscattered off the tag and received at the first, second, and third RFID readers; and at least one RFID reader in the plurality of RFID readers further configured to determine a location of the tag using the measured position parameters extracted from the signal backscattered off the tag from the single RF signal transmitted at the particular time from the first RFID reader, wherein all measured position parameters used in determining the location of the tag are extracted from said signal backscattered off the tag from said single transmission at said particular time from the first RFID reader. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A system for locating radio frequency identification (RFID) tags, the system comprising:
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a plurality of tags for backscattering radio frequency (RF) signals; and an RFID reader comprising; an RFID transmitter; and an RFID receiver; the RFID reader configured to transmit, from said RFID transmitter, an RF signal at a first location, a second location, and a third location, wherein the first, second, and third locations are different locations; the RFID reader further configured to receive, at said RFID receiver, a signal backscattered off the tag from the RF signal transmitted from the RFID reader at each of the first, second, and third locations; the RFID reader further configured to extract at least one measured position parameter corresponding to the signal backscattered off the tag and received by the RFID reader at the first, second, and third locations; and the RFID reader further configured to calculate a location of the tag using the measured position parameters. - View Dependent Claims (19, 20, 21, 22)
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Specification