L64704 LSI Logic Corporation, L64704 Datasheet - Page 199

• Manufacturer Part Number: L64704
• Description: Satellite Decoder Technical Manual 5/97
• Manufacturer: LSI Logic Corporation

Table B.4
Operation
(Damping = 1)
n
for Fixed Rate
Where
:
Group 4, APR 26 – The recommended value for CAR_KD is 207,
based on
where
Set Group 4, APR 26 to 0xCF.
QPSK Demodulator Configuration Example
CAR_KD
Data Rate (Mbaud)
R
Set CAR_KP to 0X40. Because of the limited range of CAR_KP (30
and 127) This value places it in the middle of the range.
Based on
K
or the NDAML estimator is selected (CON_SEL; Group 4, APR 35).
Figure 5.9 on page 5-19
as a function of C/N.
K
Set K
Rad/s/v.
Therefore in this example, R
R
CAR
D
D
CAR
is the Phase Detector Gain and it depends on whether the DDML
is about 10 for C/N = 4 dB (Channel Eb/No = 1 dB).
= 1,
10
20
30
C
D
is the loop’s damping,
Equation 5.11
C
=
CAR
= 10, K
CAR
-------------- -
2
Equation 5.11
n
n
= 51.5 krad/s/V, and T =
=
T
=
CARVCO
3.3 K
-------------------------------------------- -
3.3 10 1.8
------------------------------------------------------------ -
=
CAR_KP
207
n
D
(kilorad/s/volt)
on
64 32
K
= 1.8 MHz/V = 11.3 Mrad/s/V and
CARVCO
page
shows the Gains of the two phase detectors
16
32
48
on
page
10
2
n
CAR
5-18,
10
3
n
C
2
6
is in rad/s, and
CAR
5-18,
2
= 10 ms.
2 42.6
10
B
6
L
.
is in Hz.
n
= 32 K
B-11