System and Method for Locating Objects and Communicating With the Same
First Claim
1. A method for locating a transponder (MT) with a remote locator (RL), the method comprising:
- selecting an identification code (ID Code) for transmission from the RL to at least one MT, wherein each of the at least one MT has a specific associated ID Code;
generating a transmission signal for transmission by the RL, the transmission signal comprising;
a first pattern that is transmitted over a first transmission interval, wherein the selected ID Code is encoded within the first pattern;
transmitting the transmission signal from the RL for reception by the MT at a first time;
receiving the transmission signal from the RL by the MT to provide a received signal;
correlating the received signal with an ID Code stored in the MT to detect the presence of the selected ID Code in the received signal;
upon detection of the selected ID Code in the received signal, generating an acknowledgement signal;
transmitting the acknowledgement signal from the MT to the RL;
said selected ID Code being encoded in the acknowledgement signal;
receiving the acknowledgement signal from the MT by the RL at a second time;
correlating the received acknowledgement signal with the selected ID Code stored in the RL to detect the presence of the selected ID Code in the acknowledgement signal; and
upon detection of said selected ID Code in the acknowledgement signal, determining a distance between the RL and the MT as a function of an elapsed time between the first time and the second time.
2 Assignments
0 Petitions
Accused Products
Abstract
An object locator system utilizes a microtransponder (12) that is used in association with an object to be located. A remote locator (10) transmits an encoded signal in which is embedded an identification code associated with the object to be located. The microtransponder (12) receives the encoded transmitted signal and processes such signal utilizing fast fourier transform techniques. The microtransponder (12) correlates the transformed received signal with a fast fourier transformed version of an identification code associated with the microtransponder (12) and upon detection of a correlation, transmits an acknowledgement signal to the remote locator (10). The remote locator (10) determines the distance to the microtransponder (12) based upon the round trip time from transmission of the coded signal to the microtransponder (12) to the receipt of the acknowledgement signal.
23 Citations
68 Claims
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1. A method for locating a transponder (MT) with a remote locator (RL), the method comprising:
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selecting an identification code (ID Code) for transmission from the RL to at least one MT, wherein each of the at least one MT has a specific associated ID Code; generating a transmission signal for transmission by the RL, the transmission signal comprising;
a first pattern that is transmitted over a first transmission interval, wherein the selected ID Code is encoded within the first pattern;transmitting the transmission signal from the RL for reception by the MT at a first time; receiving the transmission signal from the RL by the MT to provide a received signal; correlating the received signal with an ID Code stored in the MT to detect the presence of the selected ID Code in the received signal; upon detection of the selected ID Code in the received signal, generating an acknowledgement signal; transmitting the acknowledgement signal from the MT to the RL;
said selected ID Code being encoded in the acknowledgement signal;receiving the acknowledgement signal from the MT by the RL at a second time; correlating the received acknowledgement signal with the selected ID Code stored in the RL to detect the presence of the selected ID Code in the acknowledgement signal; and upon detection of said selected ID Code in the acknowledgement signal, determining a distance between the RL and the MT as a function of an elapsed time between the first time and the second time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. An object locator system comprising:
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a microtransponder (MT) for use in association with the object to be located and responsive to a received coded signal comprising; a MT receiver circuit adapted to recognize the received coded signal when it correlates with an identification code (IC Code) associated with such MT and trigger a response thereto; a transmitter circuit adapted to transmit an acknowledgment signal after detection of the triggered response; and a remote locator (RL) for determining the distance between the RL and said object comprising; a RL transmitter adapted to transmit a coded signal for transmission to the MT; a RL receiver circuit adapted to receive the acknowledgement signal; and a time measurement circuit adapted to measure the round trip time between the transmission of the coded signal by the RL and receipt of the acknowledgment signal, whereby the distance between the MT and RL is a function of the time between the transmission of the coded signal and receipt of the acknowledgment signal. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52)
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53. An object locator system, comprising:
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at least one location transceiver adapted to be connected to or implanted in an object to be located, wherein the location transceiver comprises a broadband receiver and a low power broadband encoded signal transmitter; and a finder transceiver for communicating with the location transceiver, wherein the finder transceiver comprises a high power broadband encoded transmitter and a broadband receiver; wherein the location transceiver periodically operates in a receive mode for a first predetermined length of time and in a sleep mode for a second predetermined period of time; and wherein the finder transmitter periodically transmits a relatively high power encoded signal for a third predetermined length of time, wherein the third predetermined length of time is at least as long as the first predetermined length of time. - View Dependent Claims (56, 57, 58, 59, 60, 61, 62)
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54. (canceled)
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55. (canceled)
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63. A method for locating a transponder with a transceiver, the method comprising:
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selecting an identification code (ID Code) stored in the transceiver, for transmission from the transceiver to at least one transponder, wherein each of the at least one transponder has a specific associated ID Code; generating a transmission signal for transmission by the transceiver, wherein the transmission signal includes the selected ID Code; transmitting the transmission signal from the transceiver for reception by the transponder at a first time; receiving the transmission signal from the transceiver by the transponder to provide a received signal; correlating, utilizing Fast Fourier Transforms to correlate in the time domain, the received signal with an ID Code stored in the transponder to detect the presence of the selected ID Code in the received signal; upon detection of the selected ID Code, generating an acknowledgement signal by the transponder; transmitting the acknowledgement signal from the transponder to the transceiver; receiving the acknowledgement signal from the transponder by the transceiver at a second time; and determining a distance between the transceiver and the transponder as a function of an elapsed time between the first time and the second time. - View Dependent Claims (64, 65)
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66. A communications device for authenticating a received transmission signal comprising:
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a receiver adapted to receive the transmission signal; a signal processor coupled to the receiver and adapted to process the transmission signal and provide thereby a digital output; a digital processor coupled to the signal processor and adapted to provide a processor FFT of said digital output; a circuit configured to provide a reference FFT associated with the transponder; and a correlator coupled to the digital processor and the circuit, wherein the correlator is configured to provide a correlation output signal as a function of the inverse FFT of the complex conjugate product of the processor FFT and the reference FFT.
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67. A communications device for authenticating a received transmission signal comprising:
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means for receiving the transmission signal; means for processing the transmission signal and provide thereby a digital output; digital processor means for providing a processor FFT of said digital output; circuit means for providing a reference FFT associated with the device; and correlator means for providing a correlation output signal as a function of the inverse FFT of the complex conjugate product of the processor FFT and the reference FFT.
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68. A method of authenticating a received transmission signal by a communications device comprising:
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receiving the transmission signal; processing the transmission signal and providing thereby a digital output; digitally processing the digital output to provide a processor FFT of said digital output; providing a reference FFT associated with the device; providing a correlation output signal as a function of the inverse FFT of the complex conjugate product of the processor FFT and the reference FFT.
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Specification