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. 29, 2003
Filed:
Nov. 07, 2000
Tsunehiko Moriuchi, Kasugai, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A read channel for a hard disk includes a decision feedback equalizer (DFE) that is used to demodulate and decode a read signal from a read head or a received signal from a fast communication apparatus by eliminating intersymbol interference from sampled data of the read signal. The DFE has a feed forward equalizer (FFE) that filters the sampled data and generates filtered data. An adder is connected to the FFE and adds the filtered data with a feedback signal to generate an equalization signal. A decision unit connected to the adder compares the equalization signal with a reference signal and generates a decision signal. A shift register connected to the decision unit receives the decision signal. A feedback filter connected to the shift register and the adder receives the decision signal from the shift register and generates the feedback signal. The phase and frequency of a clock signal and the phase and frequency of the input signal are matched using the equalization signal and the decision signal. A replica signal generator connected to the shift register supplies a replica signal, which corresponds with a predetermined decision result, to the shift register in place of the decision signal during phase and frequency matching.