Affects of tone interference on the performance of QPSK and 8-PSK modulations in satellite communication

Modern satellite communication systems perform many of the functions such as channelization and switching in the digital domain after converting the IF signal into digital form using an analog-to-digital converter (ADC). Such systems may introduce spurious signals, which may arise from many possible sources including the ADC, the frequency synthesizer and other subsystems in the digital signal processor (DSP) section. The presence of such spurious signals can severely degrade the performance of the communication system especially the systems employing error correction codes. This paper presents results on the effects of tone interference signals and spurs on modern satellite links employing QPSK and 8-PSK modulations.