VITERBI DECODING METHOD AND ITS CIRCUIT

摘要

PROBLEM TO BE SOLVED: To demodulate a reproduced code of a magnetic recording and reproducing device with a simple circuit configuration. SOLUTION: In this Viterbi decoding method, a reproduction signal waveform- equalized by an equalizer is received and two comparators each having a threshold level interlocked with each other obtain positive and negative peak data and the data are selected in a prescribed time division each and the selected data are grouped. The grouped data are subject to Viterbi decoding in an opposite direction and Viterbi decoding is conducted by the method of matching final decoded data of a group with first decoded data of a succeeding group and then a simple Viterbi decoding circuit employing mainly shift registers is configured without use of an A/D converter and a microprocessor or the like.