Question

The signal given by the equation \(\sum_{n=-{\infty}}^{\infty}|x(n)|^2\) is known as __________

(a) Energy signal

(b) Power signal

(c) Work done signal

(d) None of the mentioned

I had been asked this question during an interview.

My enquiry is from Discrete Time Signals in division Discrete Time Signals and Systems of Digital Signal Processing

Answer 1

Right option is (a) Energy signal

To explain I would say: We have used the magnitude-squared values of x(n), so that our definition applies to complex-valued as well as real-valued signals. If the energy of the signal is finite i.e., 0<E<∞ then the given signal is known as Energy signal.