Howtosignalprocessing
- How do you choose a sampling rate based on frequency?
- What is the relation between cutoff frequency and sampling frequency?
- How do you choose a sampling rate?
How do you choose a sampling rate based on frequency?
The Nyquist theorem – choosing the right sample rate
The Nyquist theorem is part of the fundamentals of signal conditioning. Based on that, you must choose the sample rate at least twice as high as the maximum frequency in the signal.
What is the relation between cutoff frequency and sampling frequency?
In practice, the cutoff frequency is given as a percentage of Nyquist frequency. That is half the sampling frequency. This is because all the frequencies scale with the sampling frequency. When the sampling frequency is doubled, for example, then the cut off frequency also doubles.
How do you choose a sampling rate?
The choice of sampling rate is determined from the highest frequency present in significant amount in the signal. For audio signals we may have frequencies to above 50kHz, but only want to respond to 20kHz and below. In this case filtering would be needed to remove these high frequencies before sampling takes place.
