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:
Aug. 08, 1995
Filed:
Aug. 24, 1993
Shin'ichi Koike, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An input digital signal is applied to a subtractor where the intersymbol interference component of the signal is removed by a cancelling signal and the ISI-free signal is fed to a decision circuit to produce a binary output, from which a decision error is then detected. A greater part of the cancelling signal is generated by a nonrecursive filter connected to the decision circuit and the remainder is generated by a second-order recursive filter whose tapped delay line is connected through an adder to the output of the tapped delay line of the nonrecursive filter. The tap signals of the recursive filter are respectively multiplied with first and second feedback coefficients and applied to the adder as feedback signals. The first feedback coefficient is equal to a sum of an attenuation constant of constant value (r.sub.f) and an attenuation coefficient of variable quantity (r) and the second feedback coefficient is equal to a product of the two attenuation coefficients. The variable quantity attenuation coefficient is adaptively updated by a correlation between the decision error and a signal derived from the output of the recursive filter.