| 摘要 |
PURPOSE:To remove a DC component after NRZI modulation by converting 4-bit information into a 6-bit information so as not to continue three ''0''s or more. CONSTITUTION:Fifteen combinations out of sixteen combinations of 4-bit information are made correspond to 15 numbers a1-a6, b1-b4, c1-c3, d1, d2 at a rate of (1 to 1). These combinations can not continue three ''0''s or more independently of the connection of the front end. The remaining one combination of the 4-bit information is made correspond to e1 e.g. out of e1 and e2. If e1 is connected after c1-c3, d1, d2, three ''0''s may be continued. Therefore, said combination is made correspond to optional five combinations out of a1-a6, b1-b4 in stead of c1-c3, d1, d2 and the 4-bit information corresponding to e1 is made correspond to e2. Thus, bit conversion is performed so as not to continue three ''0''s or more. |
