Question

( ) A- When we compress a signal in the time domain, we also compress its spectrum in the frequency domain. B- Frequency shifting can be done by multiplying the signal by a sinusoidal signal in the time domain. C- Let the bandwidth of m(t) be B Hz, then the bandwidth of alt) = { mº(t)dt is 2B Hz. 2- Find the inverse Fourier transform of Y (@): [4 Points). M(O) m (1) s(t)=1 ejet 218(0-0) cos o,t [8(0-0.)+d(0+0.)] g(t)e jest G(0-0) 8( )cos 0,1 [G(@=0)+G(@+0)] -0 -Во В Y (0) 1/2 1/2 1/2 1 1/2 1/2 -0,+B":-0.-B - B 6 0 + B

Answer 1

A) False

Because compression of a signal in time domain is equal to expansion in frequency domain and vice versa.

B)False

Shifting of in frequency domain is corresponding to multiplication of time domain signal by exponential signal.

C)True.

Here,a(t)=m(2t) so,signal is compressed in time domain implies expansion of bandwidth in frequency domain.

So,for m(t),bandwidth =B Hz;

for m(2t),band width=2B Hz;