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. 15, 2008
Filed:
Dec. 05, 2001
Heikki Laamanen, Espoo, FI;
Janne Väänänen, Espoo, FI;
Heikki Laamanen, Espoo, FI;
Janne Väänänen, Espoo, FI;
Tellabs OY, Espoo, FI;
Abstract
The invention relates to a method and apparatus for improving the quality of receiver synchronization on QAM- or CAP-modulated modem connections having an adaptive linear equalizer. The invention is based on the finding that in a QAM- or CAP-modulated data transmission system where the symbol rate and the average carrier frequency are in fixed relationship with each other, the vector formed by the In-phase and the Quadrature component of the detector input signal rotates with the timing phase shift of the receiver. The quality of receiver synchronization is improved by utilizing information extracted from the vector rotation.