| 摘要 |
PROBLEM TO BE SOLVED: To suppress the divergent state of an adaptive equalizer and to perform optimum waveform equalization by the equalizer. SOLUTION: This system has the equalizer 105 which adaptively equalize the waveform of data u (n) by LMS algorithm, a Viterbi decoder 106 which discriminates reproduced data from the equalized data y (n), a Viterbi decoder 107 which discriminates reproduced data from the data u (n), and a selector 10 which extracts discrimination data d1 (n) of the Viterbi decoder 106 or discrimination data d2 (n) of the Viterbi decoder 107 and supplies them to the equalizer 105. The selector 108 uses values M1 and M2 of metrics of the Viterbi decodes 106 and 107 to extract the discrimination data d2 (n) instead of the discrimination data d1 (n) when the operation of the equalizer 105 is diverging. When the operation of the equalizer 105 is diverging, the discrimination data d2 (n) which has a lower error rate than the discrimination data d1 (n) are supplied to the equalizer 105, so equalization characteristics are so updated to approximate correct ones.
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