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. 14, 1986
Filed:
Dec. 01, 1982
Odile Macchi, Orsay, FR;
Centre National de la Recherche, Paris, FR;
Abstract
An adaptive echo canceller for a full duplex transmission system comprises a cascade arrangement of an adaptive digital filter and an automatic gain control device. The AGC device receives the output signal from the adaptive digital filter and delivers the estimate of the echo signal to the receive line for subtraction. It has a multiplier receiving the output signal and a signal representative of the multiplication factor from a gain adaptation circuit. A separate gain change circuit is connected to receive the output signal from the adaptive digital filter and simultaneously modifies the tap coefficients of said filter and the multiplication factor of the AGC device in opposite directions for maintaining the output of the adaptive digital filter in a predetermined range.