Digital data modulation/demodulation system.

摘要

A digital data modulation system having, a separator for separating a consecutive binary data sequence to four-bit code-words, a four-to-nine ([4.9]) converter for converting the four-bit code-words into nine-bit modulated code-words and a code selector for selecting a code among nine-bit code-words containing minimum three bits of "0" between a preceeding bit of "1" and its following bit of "1" so that there should not be less than two consecutive bits of "0" between a selecting code and a modulated code-word which is to be converted later by the [4.9] converter. <IMAGE>