Minimum sample frequency that allows reconstruction of information signal but VIOLATES Nyquist?

1. What is the minimum sampling frequency according to the Nyquist criteria?
2. What is the minimum sampling frequency for accurate reconstruction of the signal?
3. What happens if the sampling frequency is less than the Nyquist limit?
4. What is the minimum sampling frequency to avoid aliasing?

What is the minimum sampling frequency according to the Nyquist criteria?

Nyquist theorem in audio signals

Therefore, according to the Nyquist theorem, the optimal sample rate for the human ear is 40 kHz. This is why standard music and audio recording sample rates are close to this value. Any values greater than 40 kHz would be undetectable to most people.

What is the minimum sampling frequency for accurate reconstruction of the signal?

The minimum sampling frequency of a signal that it will not distort its underlying information, should be double the frequency of its highest frequency component. If f_S is the sampling frequency, then the critical frequency (or Nyquist limit) f_N is defined as equal to f_S/2.

What happens if the sampling frequency is less than the Nyquist limit?

When the sampling frequency drops below the Nyquist rate, the frequencies will crossover and cause aliasing.

What is the minimum sampling frequency to avoid aliasing?

a. According to the Nyquist sampling theorem, the minimum sampling frequency fs to avoid aliasing is 2 times the signal bandwidth ⇒ fs = 6 kHz.