Comtech EF Data CDM-625A Installation And Operation Manual page 586

CDM-625A Advanced Satellite Modem
Appendix F
F.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
F.5.2.1 Estimating PSD Ratio from LST
PSD = Downlink EIRP – 10 * Log (Symbol Rate)
Downlink EIRP
27 dBW
24 dBW
Symbol Rate Power Spectral Density
500 ksps
375 ksps
F–18
Revision 0
MN-CDM625A
-29.99 dBW/Hz
-31.74 dBW/Hz