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:
Nov. 22, 1988
Filed:
Aug. 08, 1986
Kazuo Yamakido, Nishitama, JP;
Takahiko Kozaki, Koganei, JP;
Shigeo Nishita, Kokubunji, JP;
Kenichi Ohwada, Yokohama, JP;
Hitachi Ltd., Tokyo, JP;
Hitachi Micro Computer Eng. Ltd., Tokyo, JP;
Abstract
A PCM coder and decoder circuit for use in a subscriber line interface circuit of a telephone communication system has a digital balancing network for removing any echo signal. The digital balancing network is formed by series-connecting a first balancing circuit having characteristics corresponding to the fixed characteristics of a coder, decoder, etc. and a second balancing circuit having characteristics corresponding to variable characteristics of an external circuit including two-wire transmission line which is connected to the coder and decoder circuit. Thus, a replica of an echo signal is precisely produced, and the circuit configuration is simplified.