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:
Apr. 21, 2009
Filed:
Jul. 01, 2005
Chun Yang, Harleysville, PA (US);
Hansheng Wang, San Jose, CA (US);
Chun Yang, Harleysville, PA (US);
Hansheng Wang, San Jose, CA (US);
SiRF Technology Holdings, Inc., San Jose, CA (US);
Abstract
A Global Navigation Satellite System (GNSS) receiver and associated method capable of acquiring weak GNSS signals from a plurality of GNSS satellites produces a GNSS signal's code time, carrier frequency, and data bit transition parameters for subsequent signal tracking and position fixing. The GNSS receiver includes a baseband signal processor with special functionalities for acquiring weak signals. In a preferred embodiment, the time and frequency uncertainty space is reduced using available information and then special techniques are used to rapidly search the remaining uncertainty space. Successive reversal of short-length correlations within a data bit interval (a block) enables data bit transition detection and data bit sign correction prior to coherent integration. Fast Fourier Transform (FFT) is applied as a bank of bandpass filters to coherently accumulate blocks of short-length correlations over extended coherent integration intervals to boost the signal power while averaging noise out despite unknown data bit transitions.