System Functionality And Operational Considerations; Figure 3-14. Conventional Fdma Link - Comtech EF Data DMD-2050E Installation And Operation Manual

DMD2050E Universal Satellite Modem
The ratio of power spectral density is normally less than 11 dB;
•
CnC operates with
•
In addition, to minimize 'false' acquisition, observe the following:
Use of IESS-315 V.35 Scrambler is highly recommended;
•
Keep the search delay range as narrow as possible – once the modem has reported the
•
search delay, narrow the search delay range to the nominal reported value +/- 5 ms – for
example, if the modem reported delay is 245 ms, narrow the search range to say 240 – 250
ms.
Use external data source (e.g. Firebird) or internal BER tester when testing Carrier-in-Carrier
•
performance.
To prevent self-locking in case the desired carrier is lost, it is recommended that the two
•
carriers have some configuration difference – for example, use different settings for Spectrum
Inversion.
3.11.4

System Functionality and Operational Considerations

Figure 3-10 illustrates a conventional, full duplex satellite link where two carriers are placed in
non-overlapping channels.
MN-DMD2050E Revision 2
modems modulators only
– not

Figure 3-14. Conventional FDMA Link

demodulators only
or .
Theory of Operation
3–30