Essential Guide to Digital Signal Processing, The

5. Sampling and the Spectra of Digital Signals

This chapter explains what digital signal processing engineers mean when they talk about the topics of sampling and the spectra of digital signals. Both subjects are important as well as interesting and, after reading this chapter, you’ll understand the meaning of this terminology.

In Chapter 2, we introduced the idea of analog signals. These are signals whose voltage amplitudes smoothly change in value as time passes. Then in Chapter 3, we discussed the important notion of the spectrum of an analog signal, which is a description, or measure, of the frequency content of an analog signal. Although you’re usually not concerned with the spectra of analog signals in your daily life (unless you’re tuning ...