Which data formats, for a random (coin toss) data stream, have (a) zero dc level; (b) built in redundancy that could be used for error checking; (c) discrete spectral lines present in their power spectra; (d) nulls in their spectra at zero frequency; (e) the most compact power spectra (measured to first null of their power spectra)?
(i) NRZ change;
(ii) NRZ mark;
(iii) Unipolar RZ;
(iv) Polar RZ;
(v) Bipolar RZ;
(vi) Split phase.