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:
Jun. 09, 2009
Filed:
Nov. 10, 2006
Shaowei Han, Palo Alto, CA (US);
Shaowei Han, Palo Alto, CA (US);
SiRF Technology, Inc., San Jose, CA (US);
Abstract
The present invention provides systems and methods that enable a standalone receiver capable of downloading navigation data under weak signal conditions. In an embodiment, a standalone navigation receiver generates predicted satellite orbits based on the tracking history of the satellites stored in the receiver. The tracking history comprises historical navigation data previously received from the satellites. The receiver uses the predicted satellite orbit to generate navigation data such as ephemeris and almanac. Since the predicted satellite is accurate, the generated navigation data is similar to the navigation data transmitted by the navigation satellites, and can therefore be used by the receiver to correct the downloaded navigation data bits. Thus many of the bits of a downloaded navigation word, especially the higher order significant bits of the word can be corrected. The remaining bit errors can be resolved based on a parity check of the word.