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:
Mar. 08, 1988
Filed:
Aug. 28, 1986
Akira Kanemasa, Tokyo, JP;
Akihiko Sugiyama, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An improved decision feedback equalizer, which removes intersymbol interference from pulse transmissions having a desired period, includes an arithmetic circuit (9) for extracting a residual intersymbol interference signal from a residual signal and a delayed residual signal which is produced by delaying the residual signal. The residual signal is produced by a subtractor circuit (2) which subtracts an estimated intersymbol interference signal from the pulse transmissions. A pattern detector circuit (11) is also provided to detect a particular consecutive pattern from a demodulated data sequence produced by a decision or detection circuit (3) for demodulating the residual signal. The residual intersymbol interference signal and a reference signal are inputted to a selector (10) responsive to the output of the pattern detector circuit. The output of the selector is sent to an adaptive filter circuit (50) which also receives the demodulated data sequence produced by the detection circuit and outputs the estimated intersymbol interference signal. The decision feedback equalizer can be modified to provide additional adaptive filter circuits for estimating intrasymbol interference, such that both intersymbol and intrasymbol interference signals can be removed from the pulse transmissions.