Research and implementation of adaptive digital pre-distortion in high-speed 32-APSK satellite communication system

Adaptive Digital Pre-distortion (DPD) is applied to the typical traveling wave tube amplifier for high-speed 32-APSK satellite communication system. The paper presents research and implementation of adaptive digital pre-distortion. We show first the transmission system model and the adaptive algorithm based on QR decomposition RLS algorithm to achieve adaptive digital pre-distortion. We also present the hardware architecture of the pre-distorter. Finally, we apply the pre-distorter to an actual satellite communication system whose the modulation is 32-APSK with symbol rate of 162.5MHz. The experimental results show that the linear effect and the performance of the system are greatly improved by the application of adaptive digital pre-distortion.