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, 1998
Filed:
Mar. 22, 1996
Kensuke Hayashi, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An echo canceler is disclosed having a voice detector. When the voice detector detects the absence of input signals, the echo canceler is trained. In the training mode, the echo canceler receives an impulse signal from an impulse generator, as input through a switching device. When the input of the echo canceler is the impulse signal, a switch is turned off, a signal on a receiving line is stored in a tap coefficient memory, and the impulse signal on a transmitting line is stored in a transmission signal memory. Using the signals stored in the two memories, a convolution operation is performed by a convolution arithmetic unit. The data of the tap coefficient memory directly before the end of training are used for the tap coefficients after the training period.