Power is defined as the amount of energy consumed per unit time. We need another measurable quantity to circumvent this problem.This leads us to the notion of “Power” Power:
What if the given signal does not decay with respect to time (as in a continuous sine wave repeating its cycle infinitely) ? The energy will be infinite and such a signal is “ not squarely-summable” in other words. Such a signal is called finite energy signal. This implies that the signal is “ squarely-summable“. The energy is finite only if the above sum converges to a finite value. Going by the second choice of viewing the “size” as the computation of the area under the square of the function, the energy of a continuous-time complex signal is defined as
Given a mathematical function (or a signal equivalently), it seems that the area under the curve, described by the mathematical function, is a good measure of describing the size of a signal. Thus the amount of electricity driving these devices will also be different.Ī given signal’s size can be measured in many ways. Both of these applications are different and have different tolerances. For example, we may be interested to know the amount of electricity needed to power a LCD monitor as opposed to a CRT monitor. It is crucial to know the “size” of a signal used in a certain application. The term “size of a signal” is used to represent “strength of the signal”. In signal processing, a signal is viewed as a function of time. Energy of a signal: Defining the term “size”: Key focus: Clearly understand the terms: power and energy of a signal, their mathematical definition, physical significance and computation in signal processing context.