Diskretizacija-Teorema O Odabiranju: F (T) - F (J)
Diskretizacija-Teorema O Odabiranju: F (T) - F (J)
Diskretizacija-Teorema O Odabiranju: F (T) - F (J)
|F(j
)|
f(t)
t
s(t)
-T
Sn
-
/2
/2
-
/2
/2
-
0
x(t)
-T
-
m
2
0
|X(j
)|
|
|S-1|
|S0|
|S1|
|S2|
-
2
-
m
0
0
0
m 0
-
0
m
0
m
Sn =
E sin( n 0 / 2)
T
n 0 / 2
X ( j) =
x(t ) e
jt
s (t ) =
Sn e jn t
0
n =
n =
dt = f (t ) s (t ) e jt dt = S n F [ j ( n0 )]
E = 1/ , 0 Sn = 1/ T
1 sin2f t n
X ( j ) = nF [ j ( m n20f m) ]
f (t ) = T
f n =
n =
f0 2 fm
2 fm
n
2f m 1 t 1
T = 2 fm
f0
2 fm
USKOPOJASNO ODABIRANJE
f(t) )|
|X(j
|
+ x(t) >
~
~
f(t)
T
1/T
x(t )
s(t)|
fm
-
2
-
m
0
0
0
m 0
0-
m
0-
m
|X(j
)|
(n+1)
0
n
0
|F2(j
)|
-
-
1+n
0
1
2
2+(n+1)
0
-
-
2
1
1 + n 0 1
2 + (n + 1) 0 2
2 2 21
n +1
n
MINIMALNA
U^ESTANOST
ODABIRANJA
KRITI^NA
U^ESTANOST
ODABIRANJA
|F1(j
)|
2 2
2
0 1
n +1
n
0 min
0c
1
2 1
2 2
n +1
2 2
1
+ 1
2
1`