Multicarrier digital pre-distortion/ equalization techniques for non-linear satellite channels

Two key advances are envisaged for future missions: (a) spectrally efficient transmission to meet the increasing demand and (b) sharing of satellite capacity among different links to meet power/massrequirements.Joint amplification of multiple-carrier DVB-S2 signals using a single High-Power Amplifier (HPA) is a particular application of satellite resource sharing. However, effects specific tosuch a scenariothat degrade power and spectral efficiencies include (a) an increased Adjacent Channel Interference caused by non-linear characteristic ofthe HPA and (b)increased peak to average power ratio. The paper studies signal processing techniques –digital pre-distortion (DPD) at the gateway and equalization (EQ) at the User Terminal–to mitigate the non-linear effects and improve power as well as spectral efficiencies.While the algorithms for DPD and EQ are described in literature, their use in multi-carrier scenario is novel and poses new challenges that are investigated in the paper