The theory and practice of digital signal processing (DSP) are currently in a mature
stage. It is difficult to imagine any modern electronic system without wide application
of DSP and, in particular, linear time-invariant algorithms for filtering, equalization,
characteristic correction and so on.
The major goal of this chapter is to introduce the theoretical basis of discrete signals
and time-invariant digital systems to help readers more easily understand the main
text dedicated to time-variant systems and to minimize the necessity to consult other
texts while reading this book. This introduction provides a superficial overview of
DSP concepts: sampling and quantization; impulse and frequency responses; Fourier,
Laplace and z-transforms; system stability and causality and finite and infinite impulse
response (IIR) digital filters (DFs). For those familiar with DSP and related subjects,
this introduction will help refresh their knowledge. For those who are unfamiliar,
this chapter can be used as the first stage of study of discrete signals and systems.
Of course, this introduction does not and cannot replace special literature and textbooks
dedicated to DSP problems. Among the latest textbooks in this area, the author
recommends Reference [1].