Patent ID: 6079041
Filing Date: 2000-06-20
Classification: G11B,H03M

Abstract:
A digital modulation circuit which encodes an m-bit dataword cut out of an input binary data stream one after another to an n-bit codeword, where n.gtoreq.m, comprising:obtaining means for obtaining respective DC components of code blocks composed of a predetermined number of the n-bit codewords, respectively, and encoding to a data block composed of the same number of m-bit datawords by using different types of m-n encoding modes, respectively;comparing means for comparing respective sizes of absolute values of the DC components with each other;selecting means for selecting the m-n encoding mode corresponding to the code block having the smallest absolute value of the DC components;encoding means for encoding the data block to a target code block by using the selected m-n encoding mode; anda multiplexer for multiplexing a number code indicating the selected m-n encoding mode to the target code block.