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. 25, 1994
Filed:
Jun. 09, 1993
Jong-Il Kim, Incheon, KR;
Daewoo Electronics Co., Ltd., Seoul, KR;
Abstract
An adaptive echo cancellation apparatus disclosed herein has three channels and a channel selection circuit. The first channel serves to block an outgoing digital signal from flowing to a transceiver. The second channel is used to directly couple the outgoing digital signal to the transceiver. The third channel serves to subtract a predicted echo signal, estimated by using the incoming digital signal, from the outgoing digital signal and to couple an error signal, representative of the difference therebetween, to the transceiver. The adaptive channel selection circuit is used to select one of the channels depending on the presence of the valid outgoing and incoming digital signals in order to effectively reduce the estimation operation. Further, the third channel is provided with a filter wherein the filter coefficients are adaptively updated by using the signs of a predetermined number of samples, thereby achieving a considerable reduction in the computational complexity.