Sampling Theorem

Sampling is what happens towards the beginning of a DSP system where we measure the signal at discrete points in time and convert the analog value to a digital representation.

It follows then that if we sample at a higher frequency we have a better representation of our original signal in the digital domain, but a great question to ask is what is the minimum sampling frequency we need to accurately reconstruct the signal at the other end?

The Sampling Theorem states that the minimum sampling rate needed to accurately reconstruct the signal is double the frequency of the highest frequency component contained in the signal. Taking the simplest example of a sine wave of 1kHz, we would need to sample at 2kHz to accurately reconstruct the signal.