摘要 |
An FDDI transmitting apparatus employs a scrambler to scramble input NRZ data which in turn is input to an NRZI-to-NRZ pre-encoder. This is in turn coupled in series with an NRZ-to-NRZI encoder to produce scrambled FDDI data for transmission whose spectral content is predistorted as a result of the scrambling to minimize spectral content peaks above about 30 MHz. The scrambling is performed according to the equation yi=xi+yi-14+yi-15. A complementary receiving apparatus employs an NRZI-to-NRZ decoder which, according to the invention, is coupled to an NRZ-to-NRZI postdecoder. This data is thence coupled to a descrambler according to the invention to recover the original data.
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