Orthonormality property

1. Sep 23, 2006

kolycholy

x(t) = sigma (from m = -infinity to infinity) zm e^(j*m*omega*t)

now my book says that using orthonormality property, we can calculate zm by calculating scalar product of x(t) and em(t) (where em(t) = e^(j*m*omega*t))
hows that possible??

please feel free to move the thread if its in wrong section!

Last edited: Sep 23, 2006
2. Sep 23, 2006

Hurkyl

Staff Emeritus
Have you tried actually computing the scalar product?

3. Sep 23, 2006

kolycholy

the book has done that for me ...
it still makes no sense why zm would equal the scalar product

4. Sep 23, 2006

Hurkyl

Staff Emeritus
Since you probably didn't come here just to say you're surprised, that means you don't understand something about the derivation -- so what didn't you understand?

5. Sep 23, 2006

antonantal

You are probably learning how to calculate the Fourier series coefficients. If that's the case see if this helps:
http://cnx.org/content/m10733/latest/?format=pdf