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:
Aug. 18, 2009
Filed:
Mar. 24, 2006
Martin Morris, Vista, CA (US);
Martin Morris, Vista, CA (US);
Free Alliance SDN BHD, Kuala Lumpur, MY;
Abstract
Methods and systems to determine the position of objects indoors or in confined areas are disclosed. A multitude of broadcast stations are transmitting an omni-directional reference signal and directional signals having each a phase-shift depending upon their specific direction. The objects whose positions are to be identified have a transponder and a means to measure the phase-shift between the omni-directional reference signal and a directional signal received. The measured time-difference indicating the relative direction to the broadcast station, which has sent the directional signal, is sent back to the broadcast station. The absolute position of the object can be determined by the results of an angular measurement of a second broadcast station. The broadcast stations can communicate amongst each other. A post-processing unit can initiate actions according to the position of an object identified.