Comtech EF Data CDM-625 - Manual (Page 300)

CDM-625 Advanced Satellite Modem Revision 15
Forward Error Correction Options MN-CDM625
7–28
Figure 7-15. Rate 1/2 BPSK, QPSK, OQPSK, LDPC Codec
1E-9
1E-8
1E-7
1E-6
1E-5
1E-4
1E-3
1E-2
1E-1
1 2 3 4 5 6 7 8 9 10 11 12
Eb/No in dB
Uncoded
BPSK/QPSK
Comtech LDPC Codec
Rate 1/2 BPSK/QPSK/OQPSK
1 2 3 4 5 6 7 8 9 10 11 12
BER
Spec limit
Rate 1/2
B/Q/OQPSK
Typical
performance
Note:
The OQPSK demod
acquisition and tracking
threshold is about 1 dB
worse than the QPSK
case