I have the discrete impulse response of a filter and i want to determine which kind of filter it is by using the DFT.
The impulse response is:
h0 = [0,1,2,1,0]
which I zero-pad for a better result
N0 = 10; h1 = [zeros(1,N0),h0, zeros(1, N0)];
Then i created the N-Point DFT of it using FFT
H1 = fft(h1);
The picture shows the plot of
Now i know that k1 = 0 represents the steady component and at first I thought that this is the spectrum of a band-stop filter but now that I read a little bit more about the DFT I'm not quite sure because the DFT is always mirrored for real signals.
So my question is: Do I have to use only one half of the DFT spectrum to determine the filter characteristics? (Which would mean that this is a low-pass filter?)