On 1/24/11 1:19 PM, Magnus Danielson wrote:
What are you *really* trying to achieve? 1-bit ADC at the end of a noisy channel?
I have a GPS receiver front end (sampler) that normally one tests by running GPS signals through it, acquiring and tracking the signals and deriving SNR estimates, etc. , but we're in a situation where we don't have either the back end processing or the GPS signals. We *do* have a signal generator, so I was looking for some analytical expression(s) that say, if you put in a tone with X SNR, this is what you should see coming out of the sampler.
It's easy to do a sort of qualitative test (put in a big signal, see if you get a square wave out), but it would be nice to be able to have a way to make a quantitative measurement, particularly of the noise figure & gain of the receiver. People have done a sort of ad hoc measurement (hooking up a spectrum analyzer to the single bit digital output of the sampler), but I was looking for something a bit more rigorous, but not to the point where *I* wanted to grind out the pages of equations.. I was hoping that someone else (e.g. Aronson) had gone through the exercise.
The interesting thing is that there *is* a fair amount of analysis of the bandlimited signal(s) and noise into a hard/soft limiter into a filter. However, there's not much on systems where there is a sampling process as well (which aliases all those harmonics down, of course). The more recent literature I was able to find tends to be of a more empirical nature (e.g. the modeling/simulation/experimental results).
And that's fine (after all, Aronson says that simple closed form solutions probably don't exist). I can crank out models with the best of them, but, philosophically, if there is a nice *simple* analytical approximation, that's nicer.
_______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
