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

The table that follows provides the spectral efficiency for all of the DVB schemes. 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 7-1. Eb/No, Spectral Efficiency and Occupied Bandwidth

Mode Type
DVB-S QPSK
DVB-S QPSK
DVB-S QPSK
DVB-S QPSK
DVB-S QPSK
DVB-DSNG 8-PSK
DVB-DSNG 8-PSK
DVB-DSNG 8-PSK
DVB-DSNG 16-QAM
DVB-DSNG 16-QAM
DVB-S2 (QPSK, 8-PSK, 16-APSK and 32-APSK with LDPC and BCH):
PER (packet error rate) = 10-7 after LDPC and BCH at the specified Es/No. This
is a theoretical value with perfect carrier recovery and symbol synchronization,
and no modem oscillator phase noise. The manufacturer decides the
implementation margin and specifies performance.
The other difference is the use of PER (packet error rate) based upon a 188 or
204 byte MPEG frame size instead of BER (bit error rate).
Also, note the use of Es/No instead of Eb/No. When links operate at constant
symbol rate so this is good method for comparing the performance of different
modulation types and code rates. The relation between the two quantities is given
by:
Eb/No = Es/No - 10xLog(Spectral Efficiency)
= 1.15
= 1.12 x Symbol Rate, for 20% Rolloff
FEC Code
Conv+RS
Conv+RS
Conv+RS
Conv+RS
Conv+RS
Conv+RS
Conv+RS
Conv+RS
Conv+RS
Conv+RS
Symbol Rate, for 35% Rolloff
x
Symbol Rate, for 25% Rolloff
x
Inner
Spectral
Eb/No At
Code
Efficiency
QEF
(bps/Hz)
Rate
1/2 4.5 0.921569
2/3 5.0 1.228758
3/4 5.5 1.382353
5/6 6.0 1.535948
7/8 6.4 1.612745
2/3 6.9 1.843137
5/6 8.9 2.303922
8/9 9.4 2.457516
3/4 9.0 2.764706
7/8 10.7 3.225490
7–3
Revision 9
MN/CDM710.IOM
Occupied *
Normalized
Bandwidth for
Symbol Rate (=
10 Mbps (35%
Bit Rate x)
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