Howtosignalprocessing
- How do you calculate DTFT of a signal?
- How is DFT calculated in FFT?
- What is the computational complexity of DFT?
How do you calculate DTFT of a signal?
Find the DTFT of the sequence x(n)=u(n−k). ⇒F[u(n−k)]=e−jωk+e−jω(k+1)+e−jω(k+2)+... ⇒F[u(n−k)]=e−jωk(1+e−jω+e−j2ω+e−j3ω+...)
How is DFT calculated in FFT?
fft , with a single input argument, x , computes the DFT of the input vector or matrix. If x is a vector, fft computes the DFT of the vector; if x is a rectangular array, fft computes the DFT of each array column. Compute the DFT of the signal and the magnitude and phase of the transformed sequence.
What is the computational complexity of DFT?
As multiplicative constants don't matter since we are making a "proportional to" evaluation, we find the DFT is an O(N2) computational procedure. This notation is read "order N-squared". Thus, if we double the length of the data, we would expect that the computation time to approximately quadruple.
