Comtech EF Data DMD50 Installation And Operation Manual page 59

DMD50 Universal Satellite Modem
4) Link Asymmetries: Various asymmetries in the forward and return link can produce
differences in the relative power of the two received signal components. These can be
both deterministic (static) or random (and time varying). An example of the former would
be the differences resulting from antenna size/gain variations between the two ends of the
link. An example of the latter would be transient power differences due to different levels
of atmospheric fading in the uplinks. CnC compensates for the asymmetries, up to a
certain extent.
In a number of ways, CnC carriers behave similar to conventional carriers in satellite links. They
are both exposed to adjacent carriers, cross-polarization and rain fade, and exhibit impairments
when any of these become too great. In addition, CnC operates in an environment where:
•
Carriers intentionally occupy the same spectral slot;
•
Performance depends upon desired and co-located interfering carrier.
MN-DMD50– Revision 3
DMD50 Modem Module
DMD50 Modem
Figure 3-10. Conceptual Block Diagram
Theory of Operation
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