M
Mike
Guest
On Sat, 16 Oct 2004 21:45:23 -0400, Mike Monett wrote:
a binary limiter output has two values, as Phil says. You're looking at
sequences of values in the binary limiter output - a much different thing.
the output of a limiter has a fixed amplitude with a random time between
transitions. That's much different that the problem you present here, in
which you have now implicitly (if not explicitly) sampled the limiter
output.
-- Mike --
You're not talking about the same thing, Mike. The distribution function ofTim Wescott wrote:
Mike Monett wrote:
Phil Hobbs wrote:
[...]
Limiters can be bipolar, unipolar, or offset--neither of these things has
anything to do with the shape of the histogram, just the location of the
peaks. And it's the histogram that determines whether a noise source is
Gaussian.
Negative. There are no peaks in the output of a limiter. Look at the output of
a FM IF in full limiting on Gaussian noise. It switches between two levels at
random intervals. The output is a square wave with random period and random
duty cycle. The average value is halfway between the two levels.
He was talking about a histogram on the output of a limiter, which
_does_ have peaks -- exactly two, centered on the upper and lower
limits. And that ain't Gaussian.
No, the output of a limiter is a binomial distribution as I point out below. But he is
not talking about a limiter. If you look at the waveform he posted earlier, he showed two
peaks with a flat spot in between. That is not a limiter. It looks more like a zero cross
detector in a MFM or RLL read channel.
a binary limiter output has two values, as Phil says. You're looking at
sequences of values in the binary limiter output - a much different thing.
Now you're solving yet another problem. Directly above, you specify thatNeither of which is a Gaussian distribution on amplitude.
The logic output is a binomial distribution, of course. And if you add a low-pass filter
to the output, you will get a Gaussian amplitude distribution with the wings truncated.
the output of a limiter has a fixed amplitude with a random time between
transitions. That's much different that the problem you present here, in
which you have now implicitly (if not explicitly) sampled the limiter
output.
It's far more complex than you think.This is too simple to be arguing about
-- Mike --