L64724 LSI Logic Corporation, L64724 Datasheet - Page 233

• Manufacturer Part Number: L64724
• Description: Satellite Receiver
• Manufacturer: LSI Logic Corporation

Table B.4
Bits
D7
D6
D5
D4
D3
D2
D1
D0
Setting
Carrier Loop Control 1 Register Bits
0
1
1
0
0
1
0
1
If the carrier is locked but the constellation is rotated by 45 degrees,
reverse the polarity of bit 6 (
Group 4, APR 42 – Set to 0xAA.
This register defines the loop bandwidths for a particular baud rate. A
good approximation to the equivalent noise bandwidth is given in
Equation
Equation B.25
For a baud rate of 21.3 Mbaud we can choose B
therefore
The loop equations are calculated as shown in
Equation
Equation B.26
QPSK Demodulator and FEC Configuration Example: High Data Rates
B
a
B
CAR_ERROR_SWAP
L
L
CAR_SWP_SWAP
=
CAR_AUTO_SWP
CAR_PED_SEL
=
=
---------------------- -
K
CAR_OPEN
0.0003125 BaudRate
tim
--------- - 1
Acronym
Reserved
Reserved
CAR_SW
B.25.
B.27.
n
2
2
T
L
n
n
tim
2
= 10.6 Krad/s.
+
-------- -
4
2
1
2
Meaning
Not significant when auto sweep is on
Carrier phase error detector output inverted
Carrier auto sweep on
–
–
Choose NDAML phase error detector
Carrier loop operates normally
Carrier sweep on
CAR_ERROR_SWAP
Equation B.26
).
L
= 6.6 Krad/s and
and
B-19