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. 22, 2000
Filed:
Feb. 18, 1998
Applicant:
Inventors:
Mati Wax, San Ramon, CA (US);
Oliver A Hilsenrath, Alamo, CA (US);
Assignee:
US Wireless Corporation, San Ramon, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04Q / ;
U.S. Cl.
CPC ...
455456 ; 455422 ;
Abstract
A method and apparatus improves the accuracy of a wireless location finding system based on the use of multipath signal signatures. A location finding apparatus measures an array covariance matrix R of a signal. The covariance matrix is compared to a database of signatures comprising calibrated signal subspaces. The comparison is based on calculating the projection of R onto each calibrated subspace. From these calculations a set of likely locations is then determined.