# [sdiy] Uniformly distributed noise generator?

cheater00 . cheater00 at gmail.com
Mon Jun 10 14:15:34 CEST 2013

```Hi Steven,
"white" refers to the frequency domain distribution, "gaussian" to the
time domain distribution. Both are independent, however gaussian white
noise is the most common by far. Any other kind is very rare.

Below is what Wikipedia says.

Cheers,
D.

----------------

Being uncorrelated in time does not restrict the values a signal can
take. Any distribution of values is possible (although it must have
zero DC component). Even a binary signal which can only take on the
values 1 or -1 will be white if the sequence is statistically
uncorrelated. Noise having a continuous distribution, such as a normal
distribution, can of course be white.

It is often incorrectly assumed that Gaussian noise (i.e., noise with
a Gaussian amplitude distribution — see normal distribution)
necessarily refers to white noise, yet neither property implies the
other. Gaussianity refers to the probability distribution with respect
to the value, in this context the probability of the signal falling
within any particular range of amplitudes, while the term 'white'
refers to the way the signal power is distributed (i.e.,
independently) over time or among frequencies.

We can therefore find Gaussian white noise, but also Poisson, Cauchy,
etc. white noises. Thus, the two words "Gaussian" and "white" are
often both specified in mathematical models of systems. Gaussian white
noise is a good approximation of many real-world situations and
generates mathematically tractable models. These models are used so
frequently that the term additive white Gaussian noise has a standard
abbreviation: AWGN.

White noise is the generalized mean-square derivative of the Wiener
process or Brownian motion.

A generalization to random elements on infinite dimensional spaces,
such as random fields, is the white noise measure.

On Mon, Jun 10, 2013 at 1:55 PM, Steven Cook
<stevenpaulcook at tiscali.co.uk> wrote:
> Hi,
>
>
>> gaussian (like normal noise circuits)
>
>
> Maybe I've not had enough coffee today, but isn't ordinary white noise
> uniformly distributed rather than gaussian?
>
> Steven Cook.
> support at spcplugins.com
> http://www.spcplugins.com/
>
> --------------------------------------------------
> From: "cheater00 ." <cheater00 at gmail.com>
> Sent: Monday, June 10, 2013 9:43 AM
> To: "synth-diy" <Synth-diy at synth-diy.org>
> Subject: [sdiy] Uniformly distributed noise generator?
>
>> Hi guys,
>> I was wondering if anyone has seen a noise circuit that is not
>> gaussian (like normal noise circuits) but instead uniformly
>> distributed.
>>
>> If you look at gaussian noise on a scope then it looks like a blurry
>> line, which has the most intensity at 0V and becomes darker and darker
>> as you move away from 0V.
>>
>> I'm looking for something that has exactly the same brightness from
>> e.g. -5V to +5V.
>>
>> Cheers,
>> D.
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>
>
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```