In this chapter, I present a specific view of signal processing. I provide the basic definitions regarding what - according to our view - signal processing should be seen as, and I elucidate in this perspective the meaning of a selection of relevant algorithms and approaches.

In this chapter, we first explain what we mean by a signal, and then we describe some characteristics such as energy, frequency, phase, power spectrum, etc. We show how to analyse it by the means of spectral analysis and Fourier transform. Moreover, as the Fourier transform does not provide any...