Comtech EF Data CDM-750 - Manual (Page 38)

CDM-750 Advanced High-Speed Trunking Modem Revision 2
Introduction MN-CDM750
1–14
Figure 1-6. L-Band Input Level vs. Symbol Rate
1.4.7 Adaptive Coding and Modulation (ACM)
System type
Adaptive Coding and Modulation, using DVB-S2 QPSK, 8PSK, 16APSK, 32APSK with Normal
Frames: Total of 25 ModCods (QPSK 1/4, 1/3 and 2/5 are excluded)
Symbol Rate Range 1 to 63 Msps
Interface
10/100/100BaseT Ethernet, with auto-sensing 10/100/1000 and auto-crossover detection or optional
Optical Gigabit Ethernet interface
Remote Es/No reporting Automatically reported from remote modem
Max span of data rate >160:1 over range of adaptation
Switch point
(decreasing Es/No)
Corresponds to Es/No (plus impairments) at QEF, ~PER = 10 -7
Switch point hysteresis Configurable from 0.0 to 0.5 dB
Max fading rate Configurable Target Es/No margin from 0.0 to 4.5 dB
Max ModCod update rate 1 update every second (no restriction on distance between ModCods)
Configurable parameters
Minimum and Maximum ModCod (ModCod4 through ModCod28)
Remote Demodulator Unlock options:
• Maintain current ModCod
• Go to minimum ModCod
• Es/No Target Margin: 0.0 to 4.5 dB0 in 0.1 dB steps.
Modulation Type Impairment selection:
• Impairment for QPSK, 8PSK, 16APSK and 32APSK: 0 to 9.9 dB in 0.1 dB steps.
• Impairment for QPSK ≤ 8PSK ≤ 16APSK ≤ 32APSK
Monitored parameters
• Tx and Rx ModCods
• Local and Remote Es/No: (-3.0 dB to +22.0dB, 0.1dB resolution)
• Config and monitor menus displaying data rate, modulation and code rate update dynamically
with ModCod