Comtech EF Data CDM-760 - Manual (Page 349)

Appendix G Revision 2
CDM-760 Advanced High-Speed Trunking Modem MN-CDM760
G–15
Figure G-7 presents a practical set of ModCods based on ModCod selection. This example
uses the DVB-S2 Network Specification. The pruned or inactive ModCods are shown along the
baseline of the plot. The transition to the next higher ModCod is the Es/No (spec) + Es/No Target
Margin (user selected) + hysteresis (0.5 dB) + modulation impairment (user selected), while a
step down is the Es/No (spec) + Es/No Target Margin + modulation impairment. In the example,
the Target Es/No Margin and Modulation Impairment are zero.
Figure G-7. Spectral Efficiency vs. Modem Es/No @ QEF (Pruned ModCods)