WAVEFORM EQUALIZER, INFORMATION REPRODUCTION DEVICE, COMMUNICATION DEVICE, WAVEFORM EQUALIZATION PROGRAM, COMPUTER READABLE RECORDING MEDIUM ON WHICH WAVEFORM EQUALIZATION PROGRAM IS RECORDED, AND WAVEFORM EQUALIZATION METHOD

摘要

PROBLEM TO BE SOLVED: To realize a waveform equalizer which can stably reduce an error rate, while taking into account of the restrictions imposed on a tap coefficient value.;SOLUTION: The waveform equalizer 20a is provided with: an FIR filter 4 for generating a post-equalization signal string by performing the waveform equalization for an input signal string; a Viterbi decoding circuit 5 for detecting a path metric difference between a correct path and an incorrect path in a Viterbi decoding process for the post-equalization signal string; a target value register 9 for setting a target value of the path metric difference; and a tap coefficient updating circuit 10 for performing the adaptation based on the error of the detected path metric difference with respect to the target value. The target value register 9 sets the target value at a value smaller than the ideal path metric difference which is based on the ideal input signal string assumed by the Viterbi decoding.;COPYRIGHT: (C)2006,JPO&NCIPI