The purpose of digital signal processing is to measure or filter continuous analog signals in the real world. Therefore, before digital signal processing, it is necessary to convert the signal from analog domain to digital domain, which is usually realized by analog-to-digital converter. The output of digital signal processing is often converted into analog domain, which is realized by digital-to-analog converter.
The course of digital signal processing introduces how to convert the motion of things into a series of numbers and extract useful information from them through calculation to meet the needs of our practical application.