Which of the following statement is not true:
1
Autocorrelation function and energy spectral density form a Fourier transform pair
2
Autocorrelation function of a real-valued energy signal is a real-valued odd function
3
The value of the autocorrelation function of a power signal at the origin is equal to the average power of the signal
4
The autocorrelation function is the inverse Fourier transform of power spectral density