In the Viterbi decoding device which the two-dimensional regenerative signal which is obtained the Viterbi decoding device and the regenerative system,

摘要

PROBLEM TO BE SOLVED: To reduce an error rate of a Viterbi decoding result by correctly calculating an assumed signal value used in branch metric calculation in a Viterbi decoding device which Viterbi-decodes a two-dimensional reproduced signal which is obtained by optically reproducing page data and indicates a value corresponding to light intensity.;SOLUTION: A two-dimensional impulse response matrix assumed, based on an amplitude of light and a bit matrix corresponding to transition of a trellis state corresponding to the two-dimensional impulse response matrix are subjected to two-dimensional convolution to obtain the square value of an assumed amplitude value of the transition. A branch metric computation circuit 8 obtains a branch metric using an assumed signal value corresponding to the square value of the assumed amplitude value of the transition. A two-dimensional Viterbi decoding circuit 4 performs Viterbi decoding, based on the branch metric.;COPYRIGHT: (C)2007,JPO&INPIT