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:
Feb. 20, 2001
Filed:
May. 19, 1999
Applicant:
Inventor:
Robert Leonard Nelson, Jr., Austin, TX (US);
Assignee:
Trimble Navigation Limited, Sunnyvale, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01S 5/02 ; G01S 3/52 ;
U.S. Cl.
CPC ...
G01S 5/02 ; G01S 3/52 ;
Abstract
A GPS navigation receiver channel tracks satellites' Doppler frequencies sequentially during the twenty milliseconds that the signal is coherent in each bit time of the navigation data modulation. It measures frequency by differencing the angles of signal-vector sums weighted by parabolic humps, exploiting the commutativity of linear processing operations to raise the signal-to-noise ratio before the nonlinear operation phase of detection.