Dynamic magnetic information storage or retrieval – General processing of a digital signal – Head amplifier circuit
Patent
1995-03-08
1999-12-14
Faber, Alan
Dynamic magnetic information storage or retrieval
General processing of a digital signal
Head amplifier circuit
360 65, G11B 509
Patent
active
060025387
ABSTRACT:
Disclosed is a PRML regenerating apparatus for regenerating a signal read by a head from a storage medium. This PRML regenerating apparatus has a waveform equalizing circuit for waveform-equalizing the read signal, a maximum-likelihood decoder for maximum-likelihood-decoding, after obtaining a determination value by comparing the equalized output with upper and lower slice levels, this determination value and a control circuit for setting variable a distance between the upper slice level and the lower slice level of the maximum-likelihood decoder. The distance between the upper and lower slice levels can be thereby set variable in accordance with an equalization characteristic. A ternary determination circuit of the maximum-likelihood decoder is constructed of a memory for storing a correspondence table of the equalized output and the upper or lower slice level versus the determination result and the next upper or lower slice level. The ternary determination circuit can be thereby actualized with a simple configuration.
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Asai Katutoshi
Hashimura Yoshihiro
Iwatsubo Masahito
Kanegae Masahide
Kondou Masao
Faber Alan
Fujitsu Ltd.
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