ABSTRACT
In this chapter, the authors explain about signals, how to represent them in their mathematical form, how to manipulate them to create new ones, and, finally, why it is necessary to study them. Electrical engineers, as well as engineers from other disciplines, are concerned with the detection of signals, their analysis, their processing, and their manipulation. They are interested in the signal amplitude, time duration, and shape. The authors introduce the reader to a number of special functions for describing particular classes of signals. The pulse function is the result of an on–off switching operation of a constant voltage source to an electric circuit. Sinc function plays an important role in the reconstruction of special signals. In communications it is desirable to transmit slow varying signals over long distances as it is done the amplitude modulation radio stations. Windowing operation is necessary in practical cases when computations are required.
