Comtech EF Data CDD-562L Installation And Operation Manual page 214

CDD-562L/564 Demodulator with IP Module
Appendix C
Example: In the diagram that follows, the (Co+No)/No measured is 4.6 dB. If Rate 1/2 QPSK is
being used, this would correspond to an E
The exact relationship used to derive the table values is as follows:
/N = 10 log
E
b 0
Where:
•
•
•
•
•
•
•
(Co+No/No )/10)
(10 -1) - 10 log
10
E /N and (Co+No)/No are expressed in dB
b 0
Bits/symbol = 1 for BPSK
Bits/symbol = 2 for QPSK
Bits/symbol = 3 for 8-PSK/8-QAM
Bits/symbol = 4 for 16-QAM
Code Rate for 'uncoded' = 1
Pay close attention to the sign of the middle term
/N of approximately 2.6 dB.
b 0
(FEC Code Rate) - 10 log
10
C–2
Revision 2
MN/CDD564L.IOM
(bits/symbol)
10