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. 16, 1998
Filed:
Oct. 13, 1994
Brian W Kroeger, Sykesville, MD (US);
Joseph B Bronder, Elkridge, MD (US);
Tod A Oblak, Indiana, PA (US);
Jeffrey S Baird, Baltimore, MD (US);
Westinghouse Electric Corporation, Pittsburgh, PA (US);
Abstract
A method and apparatus for synchronizing symbol timing for a QPSK demodulator. A matched filter pair outputs respective 'early-punctual-late' signals. The early and late signals are input to a symbol synchronizing estimator that produces an interpolation control signal used by the filters to synchronize the symbol timing to the sample timing. The punctual signal is output as an information bearing signal representing the received inphase and quadrature signals. The matched filters are interpolating matched filters. The symbol synchronizing estimator normalizes the early and late signals in a manner that allow the demodulator to 'flywheel' over signals having a low signal to noise ratio below a predetermined threshold.