Comtech EF Data CDM-625 - Estimating PSD Ratio from Satmaster; Estimating PSD Ratio Using Spectrum Analyzer

CDM-625 Advanced Satellite Modem Revision 13
DoubleTalk
Carrier-in-Carrier Option MN-CDM625
10–19
10.5.2.2 Estimating PSD Ratio from Satmaster
10.5.2.3 Estimating PSD Ratio Using Spectrum Analyzer
PSD Ratio or CnC Ratio can also be estimated using a Spectrum Analyzer capable of integrating
the signal power in a given bandwidth.
CnC Ratio (in dB) = Power
C1
(in dBm) – Power
C2
(in dBm)
PSD Ratio (in dB) = (Power
C1
– 10 log BW
C1
(in Hz)) – (Power
C2
– 10 log BW
C2
(in Hz))
= CnC Ratio – 10 log (BW
C1
/ BW
C2
)
If the two carriers have same Symbol Rate / Bandwidth, then the CnC Ratio is same as the PSD
Ratio.