Discrete signals and systems

Abstract

A discrete signal is one which is defined only at isolated discrete points in time, its value at other times being either unknown or assumed to be zero. A discrete signal thus contains only discontinuities and is best described analytically as a set of impulses. Most discrete signals are defined at equally spaced points in time but examples exist of unequal spacing which can successfully be processed. This book considers only equally spaced discrete signals. The amplitude of a discrete signal is normally considered to be an infinitely resolved function as with a continuous signal but the digital signal is a discrete signal which is an important exception to this and is classified separately.