Figure 8-1. Conceptual Block Diagram - Comtech EF Data CDM-750 Installation And Operation Manual

CDM-750 High Speed Trunking Modem
DoubleTalk Carrier-in-Carrier Option
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. Both
are exposed to adjacent carriers, cross-polarization, and rain fade, and exhibit impairments when
any of these become too great. CnC additionally operates in an environment where:
•
Carriers intentionally occupy the same spectral slot, and
•
Performance depends upon desired and co-located interfering carrier. The interfering
carrier is canceled, leaving the desired carrier for demodulation.

Figure 8-1. Conceptual Block Diagram

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