### Making White Noise with Dice

An example of a digital white noise generator is the sum of a pair of
*dice* minus 7. We must subtract 7 from the sum to make it zero
mean. (A nonzero mean can be regarded as a deterministic component at
dc, and is thus excluded from any pure noise signal for our purposes.)
For each roll of the dice, a number between
and
is generated. The numbers are distributed binomially between
and
, but this has nothing to do with the whiteness of the number
sequence generated by successive rolls of the dice. The value of a
single die minus
would also generate a white noise sequence,
this time between
and
and distributed with equal
probability over the six numbers

(C.27) |

To obtain a white noise sequence, all that matters is that the dice are sufficiently well shaken between rolls so that successive rolls produce

*independent*random numbers.

^{C.4}

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Sample Power Spectral Density