Question on PCM Sampling and Quantization order I had a doubt in my mind regarding the orders of sampling and quantization in PCM. What is the impact if the order is reversed, that is, the continuous time signal is first quantized and then sampled? I find a source on the internet claiming that quantization noise will increase with the reversal (link given), but I'm not sure why. Personally, I feel it should be unaffected as we're simply quantizing as in allowing a finite set of amplitudes first and then sampling those amplitudes. Am I missing something?
Link which claims the same: (Question 16)
https://electronicspost.com/signal-and-systems-interview-questions-and-answers/
That link provides a very superficial Q &amp; A on signals and systems.
It's not clear which kind of a sampler or quantizer they are referring to.
However, if sampling and quantization are defined as ideal mathematical operators then,
you should get exactly the same result by altering their orders. Hence the sample values should be same (meaning that the same noise also).
May be they're referring to some unstated practical ADC schemes (that I cannot recall) which do not perform ideal operations and might create different results.