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:
Dec. 06, 2011
Filed:
Jun. 02, 2010
Xiaoguang Yu, Chengdu, CN;
BO Yu, Chengdu, CN;
Xiaoyong He, Chengdu, CN;
Jinghua Zou, Chengdu, CN;
O2Micro International, Ltd., Grand Cayman, KY;
Abstract
A navigation system for detecting error on Doppler frequencies of a plurality of satellite signals measured by the navigation system is disclosed herein. The navigation system includes an offset calculator for calculating offsets of the Doppler frequencies of the satellite signals during a predetermined time period and calculating an average value of the offsets. The navigation system further includes an error detecting unit coupled to the offset calculator. The error detecting unit compares the offsets of the Doppler frequencies of the satellite signals with the average value of the offsets and determines whether the satellite signals are unavailable according to corresponding comparison results.