Real valued signal is a signal which assumes a real value for its amplitude for all instants of time. Examples are, cosωot, rect(t), u(t), r(t), δ(t), eat (a is a real value).
Complex valued signal is a signal which assumes a complex value for its amplitude atleast at one instant of time. Example is ejωot
Since ejωot = cosωot + jsinωot
1. If f(t) is a real signal then it satisfies the following relationship
f(t) = f*(t)
( f*(t) is the conjugate of f(t) )
Note: If f(t) = a + jb
then
f*(t) = (a + jb)*
f*(t) = a − jb
2. If f(t) is a purely imaginary signal then it satisfies the following relationship
f(t) = − f*(t)
