Config: Rx  Demod (Demodulation) - Comtech EF Data CDM-625A Installation And Operation Manual

CDM-625A Advanced Satellite Modem
Front Panel Operation
CONFIG: Rx  FEC  Diff Encoder On
When you select Differential Decoding as OFF, there is no way for the modem to
resolve the phase ambiguities associated with PSK modulations. For BPSK there is a
50% chance that the polarity of the data will be correct. In QPSK there is a 25%
chance that the data will be correct.
Enc=None (None,Vit,Seq,TCM,TPC,LDPC,VFEC)
Diff Encoder=On (Off,On)
6.2.1.4.4 CONFIG: Rx  Demod (Demodulation)
Demod=QPSK (B,Q,OQ,8PSK,16QAM)
FEC Rate=1/2
◄ ►
Use the arrow keys to select Demod (top line) or FEC Rate (bottom line). Press ENTER.
Then, for either, use the
dictates the FEC Rate selections:
Decoder Type
No Encoder
Non-Turbo Encoder
TPC
(with TPC/LDPC hardware option
installed)
LDPC
(with TPC/LDPC hardware option
installed)
VFEC
ULL
(VersaFEC Ultra-Low Latency)
VF2L (VersaFEC-2 Long Block) or
VF2S (VersaFEC-2 Short Block)
(1/2,3/4,7/8)
▲▼ arrow keys to select the setting. The Decoder type selected
Modulation Type
BPSK
QPSK, OQPSK
BPSK
TCM 8-PSK (FAST option)
QPSK, OQPSK
16-QAM (Vit+RS only)
BPSK
QPSK, OQPSK
8-PSK (FAST option)
16-QAM (FAST option)
BPSK
QPSK, OQPSK
8-PSK, 8-QAM (FAST)
16-QAM (FAST option)
BPSK
QPSK
8-QAM (FAST option)
16-QAM (FAST option)
BPSK
QPSK
BPSK
QPSK
6–26
MN-CDM625A
Revision 4
()
()
FEC Rate Choice
Fixed at 1/1
Fixed at 1/1
Fixed at 1/2
Fixed at 2/3
1/2, 3/4, 7/8
3/4, 7/8
5/16, 21/44
1/2 (aka 21/44), 3/4, 7/8, 0.95
3/4, 7/8, 0.95
3/4, 7/8
Fixed at 1/2
1/2, 2/3, 3/4
2/3, 3/4
Fixed at 3/4
Fixed at 0.488
0.533, 0.631, 0.706, 0.803
0.576, 0.642, 0.711, 0.780
0.644, 0.731, 0.780, 0.829, 0.853
Fixed at 0.493
0.493, 0.654, 0.734
Fixed at 0.489
0.489, 0.537, 0.586, 0.611, 0.635,
0.660, 0.684, 0.733