Sharing the on-board high power amplifier among different uplinked carriers (links) is attractive since it provides for economical and sustainable satellite missions. However, the non-linear characteristic of the satellite amplifier introduces intermodulation products leading to Adjacent Channel Interference (ACI), thereby degrading performance, more so for the spectrally efficient modulations. Towards supporting higher order modulations, this work proposes a novel distortion mitigation technique at the transmitter (predistortion) based on orthogonal memory polynomials and highlights its salient features: performance improvement, scalability and low complexity.