Alexander S. Yurkov wrote:
Certanly if this 10uV signal is the only signal in ADC input then
ADC gives zero code only. Nothing more. But we can add a noise with
spectrum out of signal spectrum (so called 'dithering'). Then signals
can be digitized by the ADC. Added noise can be canceled by digital
filtering then.
Alex,
I am familiar with the concept of noise dithering, but IMHO you can
apply it only
when the added noise is spread all over the digitization bandwidth. In
such a case you can gain
many bits of resolution doing a decimation after the oversampling.
But what you are saying is that I can put two pure sine signals at e.g.
1 MHz, one of them
of 1V amplitude, and the other of 1uV amplitude, separated by, let's
say, 1 kHz, digitize them with
a 16-bit, 100 MHz ADC and then, by simply decimating (low pass +
subsampling) and applying a
post-decimation filter, I can resolve them ? I don't think it is
possible, but, then, I have been wrong
other times...
73 Alberto I2PHD
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