Frequency-domain sampling The signal has a Fourier- transform (a) Plot X(ω) f...

Frequency-domain sampling The signal has a Fourier- transform

(a) Plot X(ω) for 0 ≤ ω ≤ 2π, a = 0.8. Reconstruct and plot X (ω) from its samples. X(2πk/N), 0 ≤ k ≤ N - 1 for

(b) N = 20

(c) N =100

(d) Compare the spectra obtained in parts (b) and (c) with the original spectrum X (ω) and explain the differences.

(e) Illustrate the time-domain abasing when N = 20.