Yes, it depends. Sometimes noise lowers SNR, sometimes it improves.
A similar scheme exists to improve ADC performance. If I remember it
correctly, LTC owns a patent where they inject pseudo-noise with known
properties, then the signal runs thru the ADC, then 'a picture of' the
added input noise is removed (maybe in some form of the decimator).
Interesting and a little obscusing the brain.
I must add that I'm not running for ultimate precision (not really
cost-bounded) but for simplicity. My ultimate is to have parasitic
functionality converted in useful functions.
- Henry
jimlux schrieb:
On 1/24/11 1:41 PM, Bob Camp wrote:
Hi
Most communications systems also have constraints based on signals in
adjacent channels. That pretty much forces a solution of "lots of filter
before lots of gain". Distributing both gain and filtering across
multiple
stages gets you into a variety of issues that map junk into the passband.
Once the junk is there, you can't get rid of it later.
And GPS (and other CDMA systems in general) is an example of a system
where it's different.The "capture effect" of limiters is well known, and
it's fascinating that the system actually works worse if the SNR is too
high, because you need the noise to be able to receive ALL the signals
at once.
_______________________________________________
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
