Performance of transparent transponder satcom system with interference

The robustness of transparent transponder satcom to uplink interference is investigated. First, the performance of transparent transponder satcom system is analyzed to uplink interference (or jamming) and the closed expression for calculating BER performance is given. Also the simulation is done for the two typical cases. It is shown that narrow-band multiple access combined with backoff of HPA provide robustness to jamming. The jamming level needed to cause all users unacceptable error bit rates must be comparable to the sum of the users´ power. And it was found that this level is generally slightly lower than that to cause transponder saturation.