DECODING DEVICE OF DIGITAL SIGNALS

• Main Authors: SHIMOTASHIRO MASAFUMI, TOKUNAGA SHINJI
• Format: Patent
• Language: English
• Published: 27.01.1998
• Edition: 6
• Subjects: INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PHYSICS

PROBLEM TO BE SOLVED: To increase no error rate and bring about stable behaviour of Viterbi decoding in a recording/reproducing device of digital signals which uses Viterbi decoding at the reproduction even when characteristics of the device are changed by structural dispersion in parts or changes in power source voltage or temperature. SOLUTION: After a reproduced signal undergoes removal of its waveform distortion by a waveform equalizing means 11 and is converted to a partial response signal of class 4 by a waveform converting means 12, it is converted to a multi-valued digital signal by an A/D converter 13 to be decoded by a Viterbi decoding circuit 14. In this case, clocks in synchronization with the bit rate of the reproduced signal are generated in a clock reproducing circuit 15 to be used for sampling clocks of the A/D converter 13. By detecting the timing error of these clocks in a sampling timing detecting circuit 15 and feeding them back to the clock reproducing circuit 15, clocks are controlled to be supplied with correct timing at all times.