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:
Jan. 29, 2008
Filed:
May. 06, 2005
Jun MO, San Jose, CA (US);
Hansheng Wang, San Jose, CA (US);
Chi-shin Wang, Half Moon Bay, CA (US);
Shaowei Han, Palo Alto, CA (US);
Kudrethaya A. Shridhara, Cupertino, CA (US);
Jun Mo, San Jose, CA (US);
Hansheng Wang, San Jose, CA (US);
Chi-Shin Wang, Half Moon Bay, CA (US);
Shaowei Han, Palo Alto, CA (US);
Kudrethaya A. Shridhara, Cupertino, CA (US);
SiRF Technology, Inc., San Jose, CA (US);
Abstract
The present invention provides a method and apparatus for a satellite navigation receiver to lock onto satellite signals in the cold start mode with no information on the receiver position, the satellite position, or time estimates stored in the receiver's memory. All satellites in a positioning system are divided into groups based on the satellite constellation structure. In an embodiment, the positioning system is the Global Positioning System (GPS) and all GPS satellites are divided into three groups. During initialization of the receiver, the satellites are searched per group to lock onto at least one satellite signal. Other satellites are then searched in a given order based on their respective distance or proximity to the first satellite acquired. This method reduces the Time-to-First-Fix (TTFF) ordinarily required by conventional receivers in the cold start mode.