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:
May. 21, 1996
Filed:
May. 05, 1994
Zheng Huang, Willow Grove, PA (US);
General Instrument Corporation of Delaware, Chicago, IL (US);
Abstract
A method and apparatus are provided for recovering and tracking the carrier in a QAM communication system, even under heavy interference conditions. A subset of fixed points is defined on an ideal constellation pattern for comparison to the data points in a received signal. The subset includes all of the points intersected by n radii (e.g., the four diagonals) of the constellation pattern. Additional points along the perimeter of the constellation pattern can also be provided in the subset. Data points received via a carrier are correlated with the fixed points of the subset in order to generate an error signal indicative of a phase difference between the fixed points of the subset and the received data points correlated therewith.