| 摘要 |
PURPOSE:To transmit an information word including a DC component even at a transmission system incapable of transmitting the DC component by selecting a code word where DSV (digital sum variation) is not diverged in coding an n-bit information word into an m-bit code word. CONSTITUTION:In coding the n-bit information word into the m-bit (m>n) code word, for example, in converting 2-bit information words beta1-beta4 into a 3-bit NRZ code word, the code words having CDS (code word digital sum) >0 and CDS<0 are combined at first, and the resulting words are allowed to correspond to the information words beta1-beta4. Then, the DSV of a channel is monitored, and when DSV>0, the code word of CDS<0 is selected and when DSV<0, the code word of CDS>0 is selected, respectively. In case of the conversion of the information word beta1 with DSV>0, for example, a code word 000 is selected, and in case of DSV<0, a code word 110 is selected. Thus, the divergence of the DSV is prevented. |
