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:
Sep. 15, 2015
Filed:
Oct. 03, 2012
Symbol Technologies, Inc., Lincolnshire, IL (US);
Mohanan Pisharody, San Jose, CA (US);
John Kramer, Los Gatos, CA (US);
Symbol Technologies, LLC, Holtsville, NY (US);
Abstract
A method and apparatus for locationing using differential phase measurements of IEEE 802.11 preambles. A first step includes providing a local clock at the same frequency as the IEEE 802.11 preambles. This step includes synchronizing the local clocks at multiple receivers with a reference clock, for example, using Synchronous Ethernet. A next step includes receiving IEEE 802.11 packets from a transmitter by at least three fixed receivers. A next step includes determining a phase offset between the local clock and any nearest cycle of a preamble in the received packets in each of the receivers. A next step includes locating the transmitter using each of the phase offsets.