Power Signal: The energy of the power signal will be infinite. Example: Periodic sequences like sinusoid. A sinusoidal signal has finite, non-zero power but infinite energy. A signal cannot be both an energy signal and a power signal.

A signal can be categorized into energy signal or power signal: An energy signal has a finite energy, 0 < E < ∞. In other words, energy signals have values only in the limited time duration. For example, a signal having only one square pulse is energy signal. For example, sine wave in infinite length is power signal.

The power of a signal is the sum of the absolute squares of its time-domain samples divided by the signal length, or, equivalently, the square of its RMS level.

Difference between energy and power signals. An energy signal has zero average power, whereas a power signal has infinite energy. The signal having finite non zero power are called as power signal while the signal having a finite non zero energy are called as energy signal.

If the signal energy over one period is larger than zero but finite, then the total energy is infinite and the signal power is finite. Therefore, the signal is a power signal. If the signal energy in one period is infinite, then both the power and the total energy are infinite.

The terms signal energy and signal power are used to characterize a signal. The definition of signal energy and power refers to any signal ( )tx , including signals that take on complex values.

Finite Length, Discrete Time Signals ‖x[n]‖2=(b∑n=a|x[n]|2)1/2. which is the least upper bound of |x[n]|. In this case, this least upper bound is simply the maximum value of |x[n]|. A signal x[n] is said to belong to the vector space lp(Z[a,b]) if ‖x[n]‖p<∞.

Explanation: A signal is said to be a power signal if and only if the average power of the signal is finite. In other words, we can say that a signal is a power signal if the energy of the signal is infinite, i.e., E = ∞.

All bounded periodic signals are power signals, because they do not converge to a finite value so their energy is infinite and their power is finite. So we say that a signal is a power signal if its power is finite and its energy is infinite. And the signal is an energy signal if its energy is finite and power is zero.

So, attenuation, distortion and noise all can impair a signal. Explanation: Bandwidth is the name for that frequency range that a signal requires for transmission and is also a name for the frequency capacity of a particular transmission medium.

The power is finite and non-zero, hence unit step function is power signal with P=12.

Chosing random t values on the interval (-∞,∞) gives you a 50% chance of either x(t) = 0 or x(t) = 1. As sample size approaches ∞, the average approaches 1/2. As long as this expression is finite and non-zero the signal is a power signal. In the case of the unit step this is cetrainly the case.

Unit Step Function Unit step function is denoted by u(t). It is defined as u(t) = {1t⩾00t<0. It is used as best test signal. Area under unit step function is unity.