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. 25, 2008
Filed:
Dec. 29, 2005
Chi-shin Wang, Half Moon Bay, CA (US);
Lianxue Xiong, Shanghai, CN;
Zhike Jia, San Jose, CA (US);
Lei Dong, Cupertino, CA (US);
Jingbin Liu, Shanghai, CN;
Chi-Shin Wang, Half Moon Bay, CA (US);
Lianxue Xiong, Shanghai, CN;
Zhike Jia, San Jose, CA (US);
Lei Dong, Cupertino, CA (US);
Jingbin Liu, Shanghai, CN;
SiRF Technology, Inc., San Jose, CA (US);
Abstract
The present invention provides GPS receivers with clock calibration for fast reacquisition of GPS signals after waking up from a sleep state or coming out of signal blockage. In a preferred embodiment, a GPS receiver comprises a local clock based on an oscillator, e.g., crystal oscillator. The GPS receiver calculates a clock calibration value based on a computed oscillator count for the period during which the GPS receiver is in the sleep state or the signal is blocked. This clock calibration value is used to calibrate the local clock after the GPS receiver wakes up or comes out of signal blockage for fast reacquisition of GPS signals.