Estimation of AM/PM Characteristics Impact on Performance of DVB-S2/S2X System with Digital Predistortion

Digital Satellite Broadcasting Systems DVB-S2 and DVB-S2X are good candidates for delivery of HDTV and UHDTV services to consumers. New types of APSK signal constellations with amplitude modulation are introduced in these standards to increase possible data rates. Use of digital predistortion techniques may considerably improve the performance of these systems and decrease required SNR thresholds. The paper investigates the impact of AM/PM phase distortions in high power amplifiers (HPA) of satellite systems and shows that for typical HPA amplifiers described by Saleh model the impact of AM/PM distortions is less considerable than impact of amplitude distortions AM/AM.