Wiley signals and systems e book TLFe BO 306

I I . 4 . Exercises

291

a) 1s x ( f ) rt.al-\iaiucd? What, :symmetry docs ~ ( thave‘!
)
b) The signal x c l ( t )is created by critical sampling of ~ ( t )Give
. the sampling
frequency
and the sample interval 7,, for this c . Sketch X,(.?W) for
U,) = Sn and for wy = 2n.

c) Sketch Xa(7w‘)for sampling with f a =

2. and wY as above.
WO

Exercise 11,19
The signal s(f)with the sketched spectiinn X ( j w ) is rriotliilated with the shown
a r r angrinent .
complex modulation
XO’O,)

1

e~~l’clt,
coo =

.105

.

.
.- .
-

a) Sketch the spectrum Y(,?w)
of the output signal.
b) Draw a11 arrmngement of sampler and reconslrnctioir filter N ( p ) that caii
deniodiil&e y ( t ) . so that x ( t ) is obtained at the output,. What are the
possible sampling lrequeucies? S1rt.tc.h I H(.Jw)I tor a suitable reconstruction
fil1,c.r.

Exercise 11.20
A signal with the sketched spectrum is sampled ideally w k h intervals T

1XO’to)