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:
Oct. 01, 1991
Filed:
Jan. 18, 1990
Applicant:
Inventors:
Didier Martineau, Conflans Sainte Honorine, FR;
Robert Ravoalavoson, Courbevoie, FR;
Assignee:
Alcatel N.V., Amsterdam, NL;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03C / ;
U.S. Cl.
CPC ...
375 60 ; 332103 ; 332107 ; 375 39 ;
Abstract
Servo-controlling position in a modulator having 2.sup.n phase and amplitude states (used for e.g. 16-QAM radio beam transmission) is achieved by monitoring the amplitude of the signal output from the modulator. In a first or inner loop, any constellation centering error in the modulation states is corrected; in a second or middle loop, any quadrature error between the modulated carriers is corrected; and in a third or outer loop, any amplitude difference between the X and Y channels input to the modulator is corrected.