How do you find the DTFT of a sequence?
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+...)
What is DTFT formula?
The DTFT of the convolution sum of two signals x1[n] and x2[n] is the product of their DTFTs, X1(ejω) and X2(ejω). That is: y [ n ] = x 1 [ n ] * x 2 [ n ] ⇔ Y ( e j ω ) = X 1 ( e j ω ) X 2 ( e j ω ) .
How do you find DTFT from DFT?
Correct Answer: Theoretical, Continuous-ω 2π-Periodic DTFT can be obtained by continuous Lagrangian-interpolation of the DFT Samples. So that the values at ω=2πk/N will be the DFT Samples X[k] for k=0,1,...,N−1 and the Interpolation-function's zero-crossings are at 2πk/N.