System and Method for Locating Objects and Communicating With the Same

A method for adjusting an internal timing and frequency in a transponder (MT) by receiving a transmission from a remote locator (RL), the method comprising:

• capturing a first portion of a first transmission sequence from the transmission during a first capture interval;
• correlating the captured first portion with a first portion of an identification code (ID Code) that is associated with the MT;
• identifying a first received time associated with the correlated captured first portion;
• extracting initial timing and phase from the correlated captured first portion;
• scheduling a second capture interval with an expected phase;
• capturing a second portion of the first transmission sequence from the transmission during the second capture interval;
• correlating the captured second portion with the first portion of the ID Code that is associated with the MT;
• identifying a second receive time associated with the correlated captured second portion;
• extracting a second timing and phase from the correlated captured second portion;
• determining a phase difference between the expected phase and the extracted second phase, and a time different between the first capture interval and the second capture interval;
• and
• adjusting a fine timing and phase associated with the receiver when the captured portions correlate, with the determined phase difference and the determined time difference.

A system for locating a transponder with a remote locator, the system comprising:

• a remote locator (RL) that is arranged to:
• select an identification code (ID Code) for transmission from the RL, wherein the selected ID Code is associated with the MT;
• generate a first transmission sequence with a first pattern, wherein the first transmission sequence is arranged for transmission in a first frame such that the first pattern is repeated in the first transmission sequence over the first frame;
• generate a second transmission sequence with a second pattern, wherein the second transmission sequence is arranged for transmission in a second frame such that each subsequent pattern in the second transmission sequence is cyclically shifted relative to the preceding pattern over the second frame;
• generate a third transmission sequence with a third pattern, wherein the third transmission sequence is arranged for transmission in a third frame;
• encode a first portion of the selected ID Code into the first transmission sequence;
• encode a second portion of the selected ID Code into the second transmission sequence;
• encode a third portion of the selected ID Code and a message for the MT into the third transmission sequence;
• transmit the first, second, and third transmission frames;
• receive an acknowledgement signal from an MT;
• and
• determine a distance between the RL and the MT as a function of an elapsed time between the transmission of the first, second, and third transmission frames and the receipt of the acknowledgement signal from the MT;
• and
• a transponder (MT) that is arranged to:
• capture at least a first portion and a second portion of the first transmission sequence;
• correlate the captured first and second portions of the first transmission sequence with the first portion of the ID Code;
• adjust a fine timing, phase, and frequency associated with the MT frequency when the captured first and second portions of the first transmission sequence is correlated to the first portion of the ID Code;
• capture a portion of the second transmission sequence;
• correlate the captured portion of the second transmission sequence with a second portion of the ID Code;
• identify a position with the second transmission frame when the captured portion of the second transmission sequence is correlated to the second portion of the ID Code;
• schedule a capture time interval for receiving the third transmission sequence based upon:
• the identified position associated with the second transmission frame, and the adjusted frequency, fine timing, and phase associated with the receiver timing from the first transmission frame;
• capture the third transmission sequence at the scheduled capture time interval;
• correlate the captured third transmission sequence with the third portion of the ID Code;
• extract the encoded message from the third transmission sequence when the captured third transmission sequence is correlated to the third portion of the selected ID Code;
• and
• transmit an acknowledgement signal to the RL from the MT.

A remote locator (RL) that is arranged to locate a transponder (MT), the RL comprising:

• a means for selecting an identification code (ID Code) that is associated with the MT;
• a means for generating sequences, wherein the means for generating sequences is arranged provide:
• a first transmission sequence with a first pattern, wherein the first transmission sequence is arranged for transmission in a first frame such that the first pattern is repeated in the first transmission sequence over the first frame;
• and
• a second transmission sequence with a second pattern, wherein the second transmission sequence is arranged for transmission in a second frame such that each subsequent second pattern in the second transmission sequence is cyclically processed relative to the preceding second pattern over the second frame;
• a means for encoding, wherein the means for encoding is arranged to encode:
• a first portion of the selected ID Code into the first transmission sequence;
• and
• a second portion of the selected ID Code into the second transmission sequence.

A transponder (MT) that is arranged to receive transmission from a remote locator (RL), the MT comprising:

• a means for synthesizing a receiver frequency;
• a means for associating an ID Code with the apparatus;
• a means for capturing transmissions;
• a means for scheduling that is arranged in cooperation with the means for capturing transmissions to selectively capture at least a portion of at least one of a first transmission frame and at least a portion of a second transmission frame;
• a means for correlating captured transmissions with the ID Code;
• a means for evaluating the correlation of the captured transmissions;
• a means for adjusting a fine timing and a phase associated with the receiver frequency when the selective evaluation of the correlation of the captured transmission yields a match with a first portion of the Code;
• and
• a means for identifying a position with the second transmission frame when the selective evaluation of the correlation of the captured transmission yields a match with a second portion of the ID Code.

A transponder (MT) that is arranged to communicate with a remote locator (RL), the RL adapted to provide a signal transmission that is coded with a transmit identification code (transmit ID Code) that is associated with the MT, the MT comprising:

• a means for synthesizing a transmit frequency for the MT;
• a means for receiving at least a portion of the transmission from the RL;
• a means for correlating received portions of the transmission;
• a means for extracting first timing and first phase information from a first captured portion of the transmission that correlates with the transmit ID Code;
• a means for extracting second timing and second phase information from a second captured portion of the transmission that correlates with the transmit ID Code;
• a means for determining a frequency offset for the transmit frequency from the first timing information, first phase information, second timing information, and second phase information;
• a means for adjusting at least one of the frequency, timing, phase, and cadence associated with the transmit frequency in response to the determined frequency offset;
• and
• a means for transmitting an acknowledgement signal to the RL using the adjusted frequency, timing, phase, and cadence that is recovered from the received signals from the RL.