To provide a means for reducing the number of bit cells per information and preventing reduction in the number of specific bit combinations.
The invention relates to a method for converting an m bit information word 1 to an n bit code word 4. The code word 4 is converted to a modulated signal 7. The code word 4 is dispersed to at least either of groups G 11 and G 12 of a first type, and at least one group G 2 of a second type. The respective code words belonging to the groups G 11 and G 12 of the first type generate encoding states S 1 and S 4 of first types. Encoding states S 2 and S 3 of second types are generated from the respective code words 4 belonging to the group G 2 of the second type. The modulated signal 7 obtained in such a manner is first converted to the series of the code words 4 and thereafter the information word 1 is obtained.
Akihiko Miyazaki
Hiroyoshi Aoki