Table 7-1. Eb/No, Spectral Efficiency And Occupied Bandwidth - Comtech EF Data CDM-710 Installation And Operation Manual

CDM-710 Broadcast Satellite Modem
Forward Error Correction Options
Another useful parameter is the occupied bandwidth is the bandwidth between -10 dB
points of the power spectral density, which are approximately:
Occupied Bandwidth = 1.19
Table 7-1 provides the Eb/No, spectral efficiency and occupied bandwidth for the CDM-710.
Table 7-2 and Table 7-3 outline these parameters per the modem's DVB schemes.
Figure 7-1 through Figure 7-7 illustrate the error performance characteristics. To convert
Es/No to Eb/No:

Table 7-1. Eb/No, Spectral Efficiency and Occupied Bandwidth*

Mode
DVB-S
DVB-DSNG
* Taken at the -10 dB points on the plot of power spectral density, the occupied bandwidth is 1.19 x
Symbol Rate for 35%, and 1.15 x Symbol Rate for 25%.
Symbol Rate, for 35% Rolloff
x
= 1.15 Symbol Rate, for 25% Rolloff
x
= 1.12 x Symbol Rate, for 20% Rolloff
Eb/No = Es/No - 10xLog(Spectral Efficiency)
Inner
Type FEC Code Code
Rate
QPSK Conv+RS 1/2
QPSK Conv+RS 2/3
QPSK Conv+RS 3/4
QPSK Conv+RS 5/6
QPSK Conv+RS 7/8
8-PSK Conv+RS 2/3
8-PSK Conv+RS 5/6
8-PSK Conv+RS 8/9
16-QAM Conv+RS 3/4
16-QAM Conv+RS 7/8
Spectral Normalized
Eb/No
Efficiency Symbol Rate (=
at QEF
(bps/Hz) Bit Rate x)
4.5 0.921569
5.0 1.228758
5.5 1.382353
6.0 1.535948
6.4 1.612745
6.9 1.843137
8.9 2.303922
9.4 2.457516
9.0 2.764706
10.7 3.225490
7–3
Revision 11
MN/CDM710.IOM
Occupied *
Bandwidth for
10 Mbps (35%
Rolloff)
1.085 12.913
0.814 9.685
0.723 8.609
0.651 7.748
0.620 7.379
0.543 6.456
0.434 5.165
0.407 4.842
0.362 4.304
0.310 3.689