# 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.