Interrogator and interrogation system employing the same
First Claim
1. An interrogator, comprising:
- a radio frequency identification (RFID) sensing subsystem configured to receive a partial response from an RFID object including a portion of a reply code; and
a control and processing subsystem, including;
a correlation subsystem configured to correlate a predetermined portion of a reference code with said portion of said reply code simultaneously in a block and provide a correlation signal therefrom that provides a signal processing gain, wherein said correlation subsystem is configured to correlate in a time domain employing an exclusive OR function or employing a Fast Fourier Transform and a convolution theorem; and
a decision subsystem configured to verify a presence of said RFID object as a function of said correlation signal.
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Accused Products
Abstract
An interrogator, methods of discerning the presence of an object, and interrogation systems employing the same. In one embodiment, the interrogation systems include multiple interrogators that communicate with a base command unit to track a location of an object. In another embodiment wherein the object is an RFID object (e.g., an object with an RFID tag), the interrogators employ signal processing techniques such as precharging the RFID object, and correlating a reference code with a reply code from the RFID object using selected techniques to increase a sensitivity of the interrogator, especially for adverse environments. In other embodiments, the interrogation systems include variations of metal instruments and sponges employed therewith. In yet another embodiment, the interrogation system includes metal interrogators capable of discerning the presence of a metal object, especially in a presence of another metal object.
265 Citations
27 Claims
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1. An interrogator, comprising:
- a radio frequency identification (RFID) sensing subsystem configured to receive a partial response from an RFID object including a portion of a reply code; and
a control and processing subsystem, including; a correlation subsystem configured to correlate a predetermined portion of a reference code with said portion of said reply code simultaneously in a block and provide a correlation signal therefrom that provides a signal processing gain, wherein said correlation subsystem is configured to correlate in a time domain employing an exclusive OR function or employing a Fast Fourier Transform and a convolution theorem; and a decision subsystem configured to verify a presence of said RFID object as a function of said correlation signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- a radio frequency identification (RFID) sensing subsystem configured to receive a partial response from an RFID object including a portion of a reply code; and
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10. A method, comprising:
- receiving a partial response from a radio frequency identification (RFID) object including a portion of a reply code;
correlating a predetermined portion of a reference code with said portion of said reply code simultaneously in a block and providing a correlation signal therefrom that provides a signal processing gain, wherein said correlating is performed in a time domain employing an exclusive OR function or employs a Fast Fourier Transform and a convolution theorem; and verifying a presence of said RFID object as a function of said correlation signal. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
- receiving a partial response from a radio frequency identification (RFID) object including a portion of a reply code;
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19. An interrogation system, comprising:
- a radio frequency identification (RFID) object; and
an interrogator configured to receive a partial response from said RFID object including a portion of a reply code, including; a correlation subsystem configured to correlate a predetermined portion of a reference code with said portion of said reply code simultaneously in a block and provide a correlation signal therefrom that provides a signal processing gain, wherein said correlation subsystem is configured to correlate in a time domain employing an exclusive OR function or employing a Fast Fourier Transform and a convolution theorem; and a decision subsystem configured to verify a presence of said RFID object as a function of said correlation signal. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27)
- a radio frequency identification (RFID) object; and
Specification