公开(公告)号：JPH1125602A

公开(公告)日：1999-01-29

申请号：JP13358298

申请日：1998-05-15

Applicant: IBM

Inventor： COKER JONATHAN D ,  EVANGEROS S EREFUMORIU ,  GALBRAITH RICHARD L ,  WALTER HIRTH

IPC: G11B5/00 ,  G11B5/012 ,  G11B20/10 ,  H03M7/00 ,  H03M13/23 ,  H04L25/03 ,  H03M13/12

Abstract: PROBLEM TO BE SOLVED: To provide a method and device for detecting the data of a partial response maximum liklihood (PRML) data channel in a direct access storage device. SOLUTION: A class IV partial response (PR4) signal is applied to a PR4 viterbi detector 60, and a PR4 viterbi output is generated, and is applied to a first matching delay circuit 64, and a delay PR4 signal is generated. The PR4 viterbi output is subtracted from the delay PR4 signal, and a synthetic signal is applied to a first filter 74 having a frequency response 1/ (1-αD ). A filtered output signal is applied to a second filter 76, and a second filter output signal is generated. The PR4 viterbi output is applied to a second matching delay circuit 86, and a delay PR4 viterbi output signal is generated. The delay PR4 viterbi output is responded to the second filter output signal to be corrected. The first filter is an infinite impulse response (IIR) filter, and the filter output signal shows a white colored noise and a corrected PRML error event.