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:
Oct. 02, 2001
Filed:
May. 23, 2000
Fumio Ueda, Tokyo, JP;
Seiichiro Hirata, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A Global Positioning System (GPS) forms a C/A code sequence by summing, beginning from a polarity inversion boundary determined by a correlation peak position detector, chips at corresponding positions in PN frames constituting each bit of navigation data; calculates pseudo ranges by computing correlation between the C/A code sequence and a reference C/A code sequence generated by the GPS terminal; and determines the position of the GPS terminal using the pseudo ranges and navigation data. The navigation data detected inside the GPS terminal is used when a received electric field detected by a received electric field intensity detector is greater than a threshold level, and the navigation data received from an external system is used when the received electric field is below the threshold level. Thus, the number of PN frames to be integrated is limited because the polarity inversion boundaries of the navigation data are detected, and hence the sensitivity (S/N ratio) is sufficient. Communication between a terminal and a base station is not always required for determining the position because the GPS terminal does not always obtain the Doppler information from the base station, reducing communication cost.