Chapter 1 Review of Continuous - Time Signals and Systems

It is natural to question how continuous-time signals and systems concepts are relevant to digital signal processing. To answer this question, it is helpful to first consider elementary signals and systems structures. In the most simplistic sense, the study of signals and systems is described by the block diagram shown in Fig. 1.1a. An input signal is fed into a system to produce an output signal. Understanding this block diagram in a completely general sense is quite difficult, if not impossible. A few well-chosen and reasonable restrictions, however, allow us to fully understand and mathematically quantify the character and behavior of the input, the system, and the output.