Digital Signal Processing Reference
In-Depth Information
precursor and three postcursor taps. Calculate the sample values of the
resulting equalized response.
−
75
−
74
−
74
−
68
18
−
41
−
62
y
=
−
68
mV
−
71
−
72
−
72
−
73
−
73
−
74
−
74
12-4
Using the received pulse response from Problem 12-3 and the coefficients
for the DLE and DFE below, calculate the sample values of the equalized
output response.
0
.
35
0
.
010
0
.
005
0
.
65
=
=
C
DLE
C
DFE
−
12-5
Derive the transfer function for a discrete linear equalizer, starting from
equation (12-21). The time-shift property of the Fourier transform will
prove useful: If
y
(
t
) has transform
F
[
y(t)
]
(f )
=
Y(f)
, then
∞
y(t
−
t
0
)e
−
2
πjf t
dt
=
e
−
2
πjf t
0
Y(f)
−∞
12-6
Derive the transfer function of the alternate passive equalizer shown in
Figure 12-20.
12-7
An alternative to the ZFS approach is the minimum mean square
error (MMSE) equalizer. Finding the coefficients using the MMSE
requires first calculating the autocorrelation matrix,
R
xx
x
T
x
, and the
=
x
T
y
. The equalizer coefficients are then
cross-correlation matrix,
R
xz
=
R
−
1
xx
R
xz
. Use the pulse response input samples from
the Problem 12-3 to calculate the coefficients for a linear equalizer with
one precursor and three postcursor taps using the MMSE algorithm.
Calculate the sample values of the resulting equalized response.
12-8
Given the pulse response in Problem 12-3, calculate the equalizer coef-
ficient progression obtained using the adaptive ZFS algorithm.
calculated as
c
=
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