Comtech EF Data SDM-2020 - Manual (Page 124)

SDM-2020 Satellite Demodulator Revision 4
Front Panel Operation MN/SDM2020D.IOM
6–60
6.1.14 (C+N)/N to C/N and E
b
/N
0
Conversion
Table 6-5 provides conversions from (C+N)/N to Eb/N0 that are useful when evaluating
satellite links with a spectrum analyzer.
The following equations were used to build the conversion table.
C/N (= Co/No) = 10*Log(10^[(C+N)/N/10]-1)
and Eb/No
= C/N – 10*Log(m*CRv) – 10*Log(188/204)
Modulation Inner Code Eb/N0 = C/N +
QPSK 1/2 0.35
QPSK 2/3 -0.89
QPSK 3/4 -1.41
QPSK 5/6 -1.86
QPSK 7/8 -2.08
8-PSK 2/3 -2.66
8-PSK 5/6 -3.62
8-PSK 8/9 -3.90
16-QAM 3/4 -4.42
16-QAM 7/8 -5.09