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:
Nov. 21, 2006
Filed:
Jan. 09, 2004
Ryota Yamasaki, Kokubunji, JP;
Atsushi Ogino, Kodaira, JP;
Masaaki Shida, Hachioji, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a positioning system using the time difference of arrival of signals between a station and a plurality of access points, each of the access points repeatedly measures a signal for calculating a position from the station, while changing any of time, the position of the station, and a frequency in use, and accumulates a plurality of measurement data. A position calculation server determines a given timing on each of a plurality of delay profiles created based on the measurement data obtained from the access points as a reception timing sample for the signal, performs a combination process with respect to the plurality of reception timing samples, and determines one reception timing for each of the access points. The position calculation server calculates the time difference of arrival of signals between the station and the access points based on the reception timings and calculates the coordinates of the position of the station.