Howtosignalprocessing
- What is the Nyquist rule?
- What happens if you sample at the Nyquist rate?
- How do I check my Nyquist bandwidth?
- What happens when you do not follow the Nyquist sampling theorem?
What is the Nyquist rule?
Nyquist's theorem states that a periodic signal must be sampled at more than twice the highest frequency component of the signal. In practice, because of the finite time available, a sample rate somewhat higher than this is necessary.
What happens if you sample at the Nyquist rate?
It can be seen that by sampling at the Nyquist rate, we can get the frequency information about the signal. However, to faithfully reconstruct the signal, we have to increase the sampling rate even more.
How do I check my Nyquist bandwidth?
C(bps) = 2B * log2M (Nyquist)
C is the capacity in bits per second, B is the frequency bandwidth in Hertz, and M is the number of levels a single symbol can take on. This "idealized" capacity equation shows us that data rate is proportional to twice the bandwidth and logarithmically proportional to M.
What happens when you do not follow the Nyquist sampling theorem?
If the Nyquist theorem is not obeyed, higher frequency information is recorded in too low a sample rate, resulting in aliasing artifacts. Several techniques can reduce aliasing in a reproduced signal.
