You can find an introduction to signals here. This post is part of a series on Image and Signal Processing.
If you are looking for the energy of a signal, you may read the dedicated note. Now, let’s dive into the power of a signal to better understand it.
Power of a signal
The power of a signal is defined mathematically as:
Note that in the latter case , where is the complex conjugate of .
The definition thus varies slightly depending on the type of signal: the ways you compute the power of real signals and complex signals are a little different. You may want to read more about complex numbers.
A signal is said to be a power signal (or with finite power) if the integral converges and is not .
If is an energy signal then it cannot be a power signal (and vice-versa). Some signals are not power nor energy signals — so beware!