Comtech EF Data CDM-625A Installation And Operation Manual page 516

CDM-625A Advanced Satellite Modem
Appendix B
The performance of the VersaFEC codes compared with the Shannon bound is shown in Figure B-2.
This puts the performance of VersaFEC at or near the DVB-S2 performance with 16 kbit blocks.
Note that SNR is used in place of Eb/No – a convention for comparing ACM ModCods. SNR is
defined as Eb/No + 10log(Spectral Efficiency).
VersaFEC ACM requires the appropriate FAST code for the maximum operating
symbol rate.
Figure B-2. VersaFEC Codes versus Shannon Capacity
B–12
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