Hello,
I have a signal that has a constant power spectral density with a corner frequency fc (e.g. 4 kHz) and I am only interested in certain bandwidth (say 200 Hz). I am wondering what would be the most accurate method to acquire this signal. Would this be ok ?
1) I low-pass filter my signal (with an analog filter that starts to cut-off at 200 Hz and) and sample at 20 000 Hz (providing that 20 000 Hz is at least twice 200 Hz + transition band)
2) Then, I could use a digital filter with a sharp transition band at 2 x 200 = 400 Hz to remove any quantization noise.
3) Finally, I average over 100 samples to update my signal every 200 Hz.
For this purpose, would this card be suitable: https://www.ni.com/en-us/shop/model/pcie-7841.html ?
Thanks !
Wilfried
