Comtech EF Data DMD-2050E - Manual (Page 87)

DMD2050E Universal Satellite Modem Theory of Operation
MN-DMD2050E Revision 2 3–45
3.11.12 Operational References
3.11.12.1 Carrier-in-Carrier Link Budget Calculation
The following steps are required for calculating the link budget for a Carrier-in-Carrier Link:
Step Procedure
1 Calculate the link budget for both carriers in the duplex link, with required CnC margin:
2 Verify that the PDS ration is within spec for the DMD2050E
3 Calculate the Allocated Bandwidth (BW) and Power Equivalent Bandwidth (PEB) for the duplex link:
• BW
Duplex Link
= Greater of (BW
Carrier 1
, BW
Carrier 2
)
• PEB
Duplex Link
= PEB
Carrier 1
+ PEB
Carrier 2
• Leased BW
Duplex Link
= Greater of (BW
Duplex Link
, PEB
Duplex Link
)
4 For an optimal link, the Leased Bandwidth and the Power Equivalent Bandwidth should be equal / nearly
equal.
5 Repeat the link budget process by selecting different Modulation and FEC, until the BW and PEB is nearly
balanced.
Find the Eb/No corresponding
to the desired BER
Add CnC Margin
Add any other margin
Use this compiled value as
the Threshold Eb/No for the
link budget