Sampled-Data Signals

Abstract

Sampled-data signals have defined values only at certain instants of time, and arise whenever continuous functions are measured or recorded intermittently. In recent years such signals have come to assume great importance because of developments in digital electronics and computing. Since it is not possible to feed continuous data into a digital (as opposed to analogue) computer, any signal or data input must be represented as a set of numerical values. In almost every case the numbers represent sampled values of the continuous signal at successive equally-spaced instants. An example of a sampled-data signal of this type has already been illustrated in figure 1.2, which shows successive values of midday temperature measured in a particular place. A further example, in which successive samples represent values of an electrical potential between two points in a circuit, is shown in figure 4.1.