Comtech EF Data CDM-625 - Manual (Page 284)

CDM-625 Advanced Satellite Modem Revision 15
Forward Error Correction Options MN-CDM625
7–12
The performance of the VersaFEC codes compared with the Shannon bound is shown in Figure 7-2.
This puts the performance of VersaFEC at or near the DVB-S2 performance with 16 kbit blocks.
Figure 7-2. VersaFEC Codes versus Shannon Capacity
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 requires both the correct hardware module (PL-0000264) to be installed
in the CDM-625 and Firmware Version 1.3.0 (or higher). ACM requires Firmware
Version 1.4.0 (or higher).