Comtech EF Data CDM-760 - DPD - Specifications

Appendix L Revision 4
CDM-760 Advanced High-Speed Trunking Modem MN-CDM760
L–11
Figure L-11. Link Margin Increase for 32-APSK DVB-S2 EB-1 ModCods, C-Band, 36MHz
Transponder
L.5 DPD – Specifications
Symbol Rate Range Minimum of 20 Msps up to a maximum symbol rate dependent on
constellation size and training approach, as follows:
• Local:
QPSK: 72 Msps
8PSK: 72 Msps
16-points, e.g. 16-APSK: 72 Msps
32-points, e.g. 32-APSK: 72 Msps
64-points, e.g. 64-APSK: 54 Msps
• Remote:
QPSK: 75 Msps
8PSK: 60 Msps
16-points, e.g. 16-APSK: 45 Msps
32-points, e.g. 32-APSK: 36 Msps
64-points, e.g. 64-APSK: 27 Msps
Coefficient Update Rate
Every 0.5 seconds
Coefficient Database Storage
15 sets, immediately loaded with modulation and coding change
Satellite Round Trip Delay
Range
0 – 300 milliseconds
Monitor Functions
• Round trip delay, in microseconds (Local only)
• Frequency offset (between transmitted outbound and received
outbound): 100 Hz resolution (Local only)
• DPD compensation, in tenths of a dB (ratio of peak-to-average
power ratios, predistorter output to input)