The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 14, 2013
Filed:
May. 05, 2010
Lawrence J. Karr, Santa Monica, CA (US);
Lawrence J. Karr, Santa Monica, CA (US);
RoundTrip LLC, Sylmar, CA (US);
Abstract
A secure communication topology can be used for communications between a locator and one or more transponders to determine the location of the transponders. An example system may include a locator that is configured to transmit an interrogation signal that is encoded for receipt by one or more of the transponders. When a transponder receives and correlates the interrogation signal with an internally stored reference sequence, the transponder can transmit one or more reply transmissions at precisely determined time delay intervals. The time delay intervals are secretly known by both the locator and the transponder. The reply transmissions can each correspond to previously sampled noise signals that are also secretly known by both the transponder and the locator.