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:
Feb. 15, 2000
Filed:
Jan. 08, 1997
Oliver Hilsenrath, Alamo, CA (US);
Mati Wax, San Ramon, CA (US);
U.S. Wireless Corporation, San Ramon, CA (US);
Abstract
A method and apparatus for location finding in a wireless communication system uses multipath signals in order to accurately determine a transmitter's location. Direct path and multipath signals from a mobile transmitter [74] arrive at an antenna array [80, 82, 84] of a base station receiver [76]. The base station determines signal signature from a subspace of an array covariance matrix. The signature is compared to a database of calibrated signal signatures and corresponding locations, and a location whose calibrated signature best matches the measured signature is selected as the most likely transmitter location. The database of calibrated signal signatures and corresponding locations is generated by a calibration procedure in which a phone [74] transmits location data derived from a GPS receiver [88] and GPS satellites [90, 92, 94] to the base station [76] which records the location information together with the signal signature of the transmitter [74]. The location information can be used to increase the performance of a cellular telephone network and provide useful services to cellular telephone customers.