11/24/2002
Noise: An Introduction
11
Averages
•Time Average of signals
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•“Ensemble” Average
–Assemble a large number of examples of the noise signal.
(the set of all examples is the “ensemble”)
–At any particular time (t0) average the set of values of  vn(t0)
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– to get the “Expected Value” of vn
•When the time and ensemble averages give the same value
(they usually do), the noise process is said to be “Ergodic”