Abstract: The present disclosure relates to location and communication systems that can be utilized for locating people, pets and other objects with a software defined radio set. A personal electronic device (PED) such as a cellular telephone, personal data assistant (PDA) or other device that include a software defined radio set can be configured for operation as a locator device. The PED transmits a signal A transponder or micro-transponder (MT) that is tagged to an object is arranged to reply to a transmission received from the PED. The PED based locator is arranged to calculate a distance between the PED and the MT using the time-of-flight (TOF) between the transmission and the receipt of a reply. The absolute geographic position of the PED can be determined using satellite navigation information, while the position of the MT relative to the PED can be determined from the TOF information.

Abstract: The present disclosure relates to location and communication systems that can be utilized for locating people, pets and other objects with a software defined radio set. A personal electronic device (PED) such as a cellular telephone, personal data assistant (PDA) or other device that include a software defined radio set can be configured for operation as a locator device. The PED transmits a signal A transponder or micro-transponder (MT) that is tagged to an object is arranged to reply to a transmission received from the PED. The PED based locator is arranged to calculate a distance between the PED and the MT using the time-of-flight (TOF) between the transmission and the receipt of a reply. The absolute geographic position of the PED can be determined using satellite navigation information, while the position of the MT relative to the PED can be determined from the TOF information.

Abstract: The present disclosure relates to location and communication systems that can be utilized for locating people, pets and other objects with a software defined radio set. A personal electronic device (PED) such as a cellular telephone, personal data assistant (PDA) or other device that include a software defined radio set can be configured for operation as a locator device. The PED transmits a signal A transponder or micro-transponder (MT) that is tagged to an object is arranged to reply to a transmission received from the PED. The PED based locator is arranged to calculate a distance between the PED and the MT using the time-of-flight (TOF) between the transmission and the receipt of a reply. The absolute geographic position of the PED can be determined using satellite navigation information, while the position of the MT relative to the PED can be determined from the TOF information.

Abstract: Communication between a remote locator and a transponder is used to determine the relative position of the transponder. The transponder and locator each include a transmitter and a receiver. The locator transmits an inquiry in the form of a relatively powerful cyclically encoded signal with repetitive elements, uniquely associated with a target transponder. Periodically, each transponder correlates its coded ID against a possible inquiry signal, determining frequency, phase and framing in the process. Upon a match, the transponder transmits a synthesized response coherent with the received signal. The locator integrates multiple cyclical response elements, allowing low-power transmissions from the transponder. The locator correlates the integrated response, determines round-trip Doppler shift, time-of-flight, and then computes the distance and angle to the transponder. The transponder can be wearable, bionically implanted, or attached to, or embedded in, some object.