CDM-570A/570AL Satellite Modem with Optional Packet Processor
Revision 5
DoubleTalk Carrier-in-Carrier Option G–21 MN-CDM570A
G.5.2 Estimate PSD Ratio
You can estimate PSD from a link budget using Downlink EIRP and Symbol Rate:
PSD = Downlink EIRP – 10 * Log (Symbol Rate)
PSD Ratio Example:
Carrier Downlink EIRP Symbol Rate Power Spectral Density
A to B 27 dBW 500 ksps -29.99 dBW/Hz
B to A 24 dBW 375 ksps -31.74 dBW/Hz
PSD Ratio (@ A) = -29.99 – (-31.74) = 1.75 dB
PSD Ratio (@ B) = -31.74 – (-29.99) = -1.75 dB
G.5.2.1 Estimate PSD Ratio from LST