Specifications

DMD20/20LBST Universal Satellite Modem Theory of Operation
MN-DMD20-20LBST Revision 14 3–41
3.15.11 Operational References
3.15.12 Carrier-in-Carrier Link Budget Calculation
The following steps are required for calculating the link budget for a Carrier-in-Carrier Link:
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 Radyne DMD20.
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