Method and apparatus for improving reception of an RFID tag response
First Claim
1. A method comprising:
- transmitting a plurality of interrogation signals to activate one or more RFID tags, each of the plurality of interrogation signals being transmitted with a different polarization, and each different polarization at a different polarization step size starting from a beginning polarization to an end polarization;
receiving a plurality of responsive signals from the one or more RFID tags;
analyzing received symbol quality data for each of the plurality of responsive signals using quality parameters to select a transmit polarization subset having received symbol quality data that is above a quality threshold;
transmitting further interrogation signals to the one or more RFID tags using the selected transmit polarization subset.
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0 Petitions
Accused Products
Abstract
A method and apparatus for improving reception of responsive RFID signals is provided. The method includes transmitting a plurality of interrogation signals each having a different polarization to activate one or more RFID tags. Responsive signals from the RFID tags are analyzed for receive symbol quality data to select a transmit polarization subset. These polarizations are then used for transmitting further interrogation signals to the RFID tags. The apparatus includes a dual element orthogonal radiator coupled to a transmitter and receiver. A processor controls the transmitter and receiver to transmit a series of RFID interrogation signals each having a different polarization, and receive a series of responsive signals from one or more RFID tags. The responsive signals are analyzed to select a particular a transmit polarization subset that will improve reception of future responsive signals from the RFID tags.
11 Citations
18 Claims
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1. A method comprising:
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transmitting a plurality of interrogation signals to activate one or more RFID tags, each of the plurality of interrogation signals being transmitted with a different polarization, and each different polarization at a different polarization step size starting from a beginning polarization to an end polarization; receiving a plurality of responsive signals from the one or more RFID tags; analyzing received symbol quality data for each of the plurality of responsive signals using quality parameters to select a transmit polarization subset having received symbol quality data that is above a quality threshold; transmitting further interrogation signals to the one or more RFID tags using the selected transmit polarization subset. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method comprising:
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transmitting a plurality of interrogation signals to activate one or more RFID tags, each of the plurality of interrogation signals being transmitted with a different polarization; receiving a plurality of responsive signals from the one or more RFID tags; analyzing received symbol quality data for each of the plurality of responsive signals using quality parameters to exclude certain polarizations to provide a selected transmit polarization subset having received symbol quality data that is above a quality threshold; transmitting further interrogation signals to the one or more RFID tags using the selected transmit polarization subset; and wherein transmitting the plurality of interrogation signals further comprises determining a beginning polarization, an end polarization and a polarization step size for transmitting a plurality of interrogation signals. - View Dependent Claims (10, 11, 12, 13, 14)
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15. A system comprising:
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an antenna system having a first antenna element with a first polarization and a second antenna element having a second polarization being orthogonal to the first polarization; a transmitter coupled to the antenna system; a receiver coupled to the antenna system; a processor coupled to the transmitter and receiver and programmed to; control the transmitter to transmit a series of RFID interrogation signals to one or more RFID tags, each of the series of RFID interrogation signals having a varied transmit polarization; control the receiver to receive a series of responsive signals from the one or more RFID tags; analyze received symbol quality data for each of the series of responsive signals using quality parameters to select a transmit polarization subset having received symbol quality data that is above a quality threshold; and transmit further interrogation signals to the one or more RFID tags using the selected transmit polarization subset; and wherein the processor is further programmed to periodically re-transmit the series of RFID interrogation signals at different polarization step sizes. - View Dependent Claims (16, 17, 18)
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Specification