| 摘要 |
<p>A digital signal modulator modulates an input digital data code to a channel code which has more bits than that of the input data code. The digital signal modulator comprises an NRZI transformer and a modulator. The NRZI transformer NRZI-transforms an input channel code and the modulator then modulates the input data code into a channel code. The modulation is implemented by selection of a channel code so that the DSV converges to zero from two channel codes assigned in advance to each of input data codes. The above two channel codes have different polarities of CDS values after the NRZI transform. The channel code is defined so that the number of '1's in the channel code is odd if a value of the CDS equals zero after the NRZI transform. <IMAGE></p> |
