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CDM-750 Advanced High-Speed Trunking Modem
Introduction
1.4.7
Adaptive Coding and Modulation (ACM)
System type
Symbol Rate Range
Interface
Remote Es/No reporting
Max span of data rate
Switch point
(decreasing Es/No)
Switch point hysteresis
Max fading rate
Max ModCod update rate
Configurable parameters
Monitored parameters
Figure 1-6. L-Band Input Level vs Symbol Rate
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)
1 to 63 Msps
10/100/100BaseT Ethernet, with auto-sensing 10/100/1000 and auto-crossover detection or optional
Optical Gigabit Ethernet interface
Automatically reported from remote modem
>160:1 over range of adaptation
Corresponds to Es/No (plus impairments) at QEF, ~PER = 10
Configurable from 0.0 to 0.5 dB
Configurable Target Es/No margin from 0.0 to 4.5 dB
1 update every second (no restriction on distance between ModCods)
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
• 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
1–13
Revision 1
MN-CDM750
-7
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