| 摘要 |
PROBLEM TO BE SOLVED: To provide an automatic equalizer in which flexible control is performed on the basis of quality evaluation of a reproduced signal and a convergence result having good equalization characteristics can be obtained. SOLUTION: Amplitude correction is carried out for the reproduced signal by a variable gain amplifier 20, and filter processing of an equalization errorεcalculated by an adder 7 by characteristic parameters (c) calculated by an adaptive control part 9 is carried out by a time constant filter circuit 8 on the basis of a level and/or level variation of an envelop waveform of the reproduced signal detected by envelop detecting circuits 21, 11, the tap coefficient of a coefficient memory 10 is updated via the adaptive control part 9 on the basis of filter processed equalization errorε', and it is outputted to a digital filter 4. Also, the characteristic parameter (c) can be calculated by the adaptive control part 9, by using not only the level and/or level variation of a reproduced signal but also temporal variation of a derivation (tilt information)of a level or level variation of the envelop waveform of the reproduced signal. COPYRIGHT: (C)2006,JPO&NCIPI
|
