Quantum and Evolution Series Installation and Operating Handbook
8-34
N
N
+
C
0
N
E
=
N
C
0
S
0
N
E
0
t
0
N
E
0
Dec
0
N
E
0
b
0
15.5
16.0
16.5
17.0
17.5
18.0
18.5
19.0
19.5
15.38
15.89
16.40
16.91
17.42
17.93
18.44
18.94
19.45
>20 =(C+N)
/
N
(error <0
.04dB)
Example:
8SPK with 2/3 Rate TCM FEC, & RS=(219,201,9)
(C+N)/N=
8.4dB
C/N=
7.72dB
8PSK so
subtract 4.77dB
2/3 Rate FEC, so
add 1.76dB
RS Code (219,201,9) so
add 0.37dB
Measure
Look up
Calculate Eb/No = C/N - 2.64dB
