Estimating Psd Ratio; Estimating Psd Ratio From Lst - Comtech EF Data CDM-625 Installation And Operation Manual

CDM-625 Advanced Satellite Modem
DoubleTalk Carrier-in-Carrier Option
10.5.2

Estimating PSD Ratio

PSD can be estimated from a link budget using Downlink EIRP and Symbol Rate:
PSD Ratio Example:
Carrier
A to B
B to A
PSD Ratio (@ A) = -29.99 – (-31.74) = 1.75 dB
PSD Ratio (@ B) = -31.74 – (-29.99) = -1.75 dB
10.5.2.1

Estimating PSD Ratio from LST

PSD = Downlink EIRP – 10 * Log (Symbol Rate)
Downlink EIRP
27 dBW
24 dBW
Symbol Rate
500 ksps
375 ksps
10–18
Revision 13
MN-CDM625
Power Spectral Density
-29.99 dBW/Hz
-31.74 dBW/Hz