Dynamic information storage or retrieval – Binary pulse train information signal – Including sampling or a/d converting
Reexamination Certificate
2005-09-06
2005-09-06
Huber, Paul W. (Department: 2653)
Dynamic information storage or retrieval
Binary pulse train information signal
Including sampling or a/d converting
C369S047150
Reexamination Certificate
active
06940800
ABSTRACT:
The present invention provides an apparatus and a method for precisely and adequately evaluating actual quality of reproduced data whenever applying a maximum likelihood decoder for converting signal reproduced from a recording medium into binary signal. Based on data arrays of a pair of binary data outputted from a “Viterbi” decoder, SAM values are secured by selecting any of path-metric differential values (00) and (11) being the difference between a pair of values compared when renewing path-metric values PMM (00) and (11) outputted from the “Viterbi” decoder. The minimum SAM value for an ideally-reproduced signal is outputted from a constant generating circuit. If the SAM values are verified as valid, and yet, if the SAM values coincide with the equation “input SAM values”≦“data value outputted from the constant generating circuit”, then squared values outputted from a square circuit are averaged by an averaging circuit. Finally, the average value is outputted as the reproduced signal evaluation.
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Fujimoto Kensuke
Fukumoto Atsushi
Tanaka Yasuhito
Yoshimura Shunji
Frommer William S.
Frommer & Lawrence & Haug LLP
Huber Paul W.
Sony Corporation
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