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. 14, 1981
Filed:
Dec. 10, 1979
Applicant:
Inventors:
Firmin Bigo, LaGaude, FR;
Francois Caron, Cagnes, FR;
Assignee:
International Business Machines Corp., Armonk, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04L / ; H04L / ;
U.S. Cl.
CPC ...
375 77 ; 370 20 ; 375 39 ; 375 43 ; 375 50 ; 375 15 ;
Abstract
A method and device which, in a receiver forming part of a data transmission system using DSB-QC modulation and wherein the transmitter generates a first sequence of successive carrier phase changes of 180.degree. taking place at the signaling rate 1/T followed by a second sequence of pseudo-random carrier phase changes of 0.degree. and 180.degree., with the first of these being a 0.degree. phase change, permit detecting the beginning of said second sequence. The received signal is filtered to extract therefrom its components at frequencies f.sub.1 and f.sub.2 defined as