Digital Signal Processing Reference
In-Depth Information
as in Figure 11.26. If we process the signal with the network in Figure 11.27
where the filters
L
are half-band lowpass and highpass respec-
tively, the output spectrum will be swapped as in Figure 11.28.
(
z
)
and
H
(
z
)
l
g
r
,
y
i
d
.
,
©
,
L
s
-
π
-3
π/
4
-2
π/
4
-
π/
4
0
π/
4
2
π/
4
3
π/
4
π
Figure 11.26
Original spectrum.
L
(
z
)
2
↓
2
↑
H
(
z
)
[
]
+
[
]
x
n
y
n
2
↓
2
↑
H
(
z
)
L
(
z
)
Figure 11.27
Spectral “swapper”.
-
π
-3
π/
4
-2
π/
4
-
π/
4
0
π/
4
2
π/
4
3
π/
4
π
Figure 11.28
“Swapped” spectrum.
