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:
Jan. 27, 1976
Filed:
Aug. 06, 1974
Applicant:
Inventors:
Etienne Penicaud, Chaville, FR;
Maurice Lienard, Marseille, FR;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
1791702 ; 178 / ; 3401 / ;
Abstract
The invention comes within the branch of digital data transmission on a telephone line having four wires comprising echo suppressors. In order to be able to neutralize these suppressors during a simultaneous bilateral data transmission, a neutralization signal is developed in a purely digital device basically using a PCM coder, counting the changes in sign of the line signal. The use of digital filters to identify the characteristic frequency preceding the transmission is thus avoided.