Comtech EF Data Vipersat SLM-5650A, Installation And Operation Manual

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SLM-5650A Satellite Modem
Revision 10
Appendix H G–18 MN-SLM-5650A
G.3.6 Validating Carrier-in-Carrier Performance
Carrier-in-Carrier performance can be easily validated by verifying that Eb/No degradation due to
Carrier-in-Carrier is within published specification for the observed Power Spectral Density Ratio.
The following procedure is recommended for validating Carrier-in-Carrier performance.
Step Task
1 Setup a conventional side-by-side link of the desired Eb/No.
a. Carrier-in-Carrier should be OFF.
b. Record the Eb/No as displayed by the Modems.
c. Observe the two carriers on a spectrum analyzer and record the PSD ratio.
Example Link:
•
Full duplex 512 kbps, QPSK, LDPC 2/3 circuit between 4.6 m and 2.4 m antennas
• Recorded Eb/No = 2.6 dB (at both modems)
•
PSD Ratio = 1.2 dB (measured at larger Antenna)
2 Relocate one of the carriers on top of the other carrier:
a. Enable Carrier-in-Carrier.
b. Record the Eb/No as displayed by the Modems.