METHOD FOR DECIDING MULTIVALUED DATA AND INFORMATION RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To reduce errors in detecting multivalued data in processing of a short period of time even when distributions of output data corresponding to each value of read multivalued data overlap each other. SOLUTION: A table obtained by storing a read signal value for multivalued data of combinations is prepared with respect to all combinations of m pieces of continuous multivalued data. A reproduced signal obtained by reading unknown multivalued data is converted from an analog signal into a digital signal on the basis of a reference clock and then, temporarily classified to any value of multivalued data with a prescribed threshold to be a decision candidate about multivalued data obtained by reading a value in the vicinity of the temporarily classified value. A combination with the minimum difference between a read signal value stored in the table and the signal value of the converted reproduced signal is calculated among combinations of the decision candidates for m pieces of continuous reproduced signals to be decided to be a combination of values of multivalued data obtained by reading the combination. COPYRIGHT: (C)2003,JPO