curfmanm@prism.CS.ORST.EDU (Matthew Curfman) (01/22/91)
A couple of days ago, someone requested some information regarding
the static problem of the GS while digitizing, and the response
from another person stating that the static was coming from an aliasing
problem.
Aliasing is a property of anything that takes an analog component and
digitizes it. The simple rule of thumb is that the frequency of the
signal applied to the digitizer should never exceed one half of the
sample rate. Therefore, using a 22 khz sample rate, no frequency greater than
11 khz should be sampled. This is where the proper use of filters ahead
of the digitizer can lead to much clearer samples.
If the frequency of the signal applied to the digitizer becomes higher
than one half of the sample rate, the time available to digitize that
signal is too short to digitize it correctly.
I believe this is why a Compact Disc's sample rate is 41.4 khz, creating
a maximum output frequency of roughly 20 khz.
I invite inquires/corrections, as this is simply my understanding of it from
my clases and designs using A/D converters.
_______________________________________________________________________________
Matt Curfman Technovelty. Inc.
curfmanm@prism.cs.orst.edu Oregon State University
OSU says what it says. I say what I say. We don't say the same thing.
_______________________________________________________________________________
Matt Curfman Technovelty. Inc.
curfmanm@prism.cs.orst.edu Oregon State University
OSU says what it says. I say what I say. We don't say the same thing.