Comtech EF Data Vipersat SLM-5650A, Инструкция по установке и эксплуатации

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SLM-5650A Satellite Modem
Revision 10
Appendix H G–15 MN-SLM-5650A
G.3.4.3 Power Limited Links
Carrier-in-Carrier can provide substantial savings even when the original link is power limited.
Spreading the carrier by using a lower modulation and/or FEC along with latest FEC such as
VersaFEC can substantially reduce the total power which can then be traded with bandwidth
using Carrier-in-Carrier. The concept is illustrated with the following examples:
The conventional link is using 8-PSK, TPC 3/4:
Switching to VersaFEC and using a lower order modulation – e.g.,
QPSK, VersaFEC 0.803 increases the total occupied bandwidth,
while reducing the total power equivalent bandwidth:
Now using CnC, the second QPSK, VersaFEC 0.803 carrier can
be moved over the first carrier – thereby significantly reducing the
total occupied bandwidth and total power equivalent bandwidth
when compared to the original side-by-side 8PSK, TPC 3/4
carriers:
To continue, consider this example:
Satellite & Transponder IS-901 @ 342º W, 22/22 (EH/EH)
Earth Station 1 Africa – 9.2 m
Earth Station 2 Africa – 4.5 m
Data Rate 2.048 Mbps / 2.048 Mbps