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. 01, 1997
Filed:
Aug. 10, 1994
Fujitsu Limited, Kanagawa, JP;
Abstract
A digital subscriber loop interface unit, connected to a digital subscriber loop, includes an echo canceler for carrying out a echo canceling operation, a decision feedback equalizer for carrying out an equalizing operation, and a transversal filter, provided in at least one of the echo canceler and the decision feedback equalizer, in which a plurality of taps among all taps are grouped into groups, each group including a predetermined number of taps continuously arranged, a single tap coefficient being assigned to the taps in each group. A digital subscriber loop interface unit may include an echo canceler for carrying out a echo canceling operation by using a value obtained by adding +1 to a symbol value represented by a 2B1Q code. Further, the echo canceler may have a jitter echo canceler in which a convolution operation is carried out by using a value obtained by adding +1 to a symbol value represented by the 2B1Q code, the tap coefficient used in the convolution operation is changed in accordance with a time elapsing from occurrence of the jitter. Furthermore, a digital subscriber loop interface unit may have a low-pass filter in which a filter coefficient is changed based on whether the decision feedback equalizer is in or after a pull-in step.