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:
Sep. 25, 2007
Filed:
Nov. 22, 2000
Timothy Forrest Settle, Alpharetta, GA (US);
Thomas Peter Krauss, Algonquin, IL (US);
Kumar Ramaswamy, Plainsboro, NJ (US);
Timothy Forrest Settle, Alpharetta, GA (US);
Thomas Peter Krauss, Algonquin, IL (US);
Kumar Ramaswamy, Plainsboro, NJ (US);
Thomson Licensing, Boulogne-Billancourt, FR;
Abstract
A hierarchical QAM system allows the transmission of different sources by embedding the relative constellation points. A QAM transmitting system, includes a source of a level 1 and a level 2 data stream, each data stream carrying successive symbols. A hierarchical QAM transmitter, coupled to the level 1 and level 2 data stream source, generates a hierarchical QAM signal in which a level 1 symbol is represented by a data point in one of four quadrants in the I-Q plane, and a level 2 symbol is represented by the data point in one of four sub-quadrants surrounding a center point of the quadrant containing the level 1 data point. The level 2 data point is spaced away from the center point by a grouping factor set to more closely match the bit error rate performance of the level 1 and level 2 data streams.