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:
Sep. 06, 1988
Filed:
Sep. 17, 1985
Akira Kanemasa, Tokyo, JP;
Akihiko Sugiyama, Tokyo, JP;
NEC Corporation, , JP;
Abstract
A first difference signal is obtained by subtracting an echo replica from a mixed signal which consists of a received signal and an echo. The echo replica is produced in an adaptive digital filter using an error signal. The first difference signal includes the received signal and a residual echo, and is delayed in a manner to produce a delayed first difference signal. The delayed first difference signal is subtracted from the first difference signal to obtain a second difference signal. Thereafter, a polarity of the residual echo included in said second difference signal is detected. The error signal is obtained based on the detected polarity, and then is applied to the adaptive digital filter.