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CHAPTER 12.
WIDESENSE STATIONARY PROCESSES
12.4.2.2
Gaussian Approximations
When one hears the term “white noise”, one usually also hears the word “Gaussian”. Engineers
are prone to use the term
additive white Gaussian noise
(AWGN) to describe a
twofold approxi
mation
to some noise sources in electronic systems (e.g., thermal noise). In addition, the (ergodic)
assumption that a real process
n
(
u, t
) can be modeled as Gaussian in practice is a matter of sta
tistical observation and engineering experience, i.e., the model has proved reasonable based on
observations, useful in design, and a good predictor of performance in subsequent tests.
The following are two models of types of electronic noise that often are assumed to be Gaussian.
It should be noted that these models themselves are approximations to real processes, and one
should not confuse the fact that a model leads in some way to a Gaussian process, with the
corresponding real process being Gaussian. There always is an approximation/assumption, often
well justified and supported by experience, that is made when describing a sample function of a
real process as AWGN.
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 '07
 ToddBrun
 Normal Distribution, Probability theory, Characteristic function, point events, lim Φzs

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