Question

5473ca8c581e2a3f28523bd8

Answer 1

You need to relate the energy to autocorrelation:
Energy:
`E = int_0^A |f(t)|^2 dt`
Autocorrelation is the convolution of the signal onto itself.
`R(tau) = int_0^A f(t)f(t-tau) dt`

So Autocorrelation defines signal energy at zero shift, i.e.:
`E = R(0) = int f(t)[f(t-tau)]_(tau=0) dt=int f^2(t) dt`.

So the answer is yes you do. Realistically if you know the structure `f(t)` then you can calculate the Autocorrelation by convolving with itself...

Hope this helps...
Best regards