The impact of in-band and adjacent channel interferers on SATCOM links

The satellite transponder is the most vulnerable part in a SATCOM system. Especially transparent transponders amplifying and retransmitting the uplink signal at the downlink frequency are widely used in today's satellite communication systems. All signals within the transponder bandwidth, which are received accidentally or even introduced intentionally, will be retransmitted reducing the available energy to the user signal. In this paper it is shown, that simple modulation modes already influence effectively satellite transmission links.