Multiple Model Linearization Solution for Cellular Base Station Power Amplifiers

A multiple model adaptive digital pre-distortion (DPD) scheme is proposed for use in a cellular base station Power Amplifier (PA). The PA is excited by rapidly changing wideband signals. The changes in the signals are caused by variations in power levels and bandwidths. These changing signals can cause a significant change in the dynamic characteristics of the PA. The proposed multiple model DPD scheme can track and compensate for the changing dynamic characteristics of the PA. The proposed scheme offers reduced computational complexity in comparison to old published methods. Experiments are performed on a Phoenix PA excited by two- and four- carrier Wideband Code Division Multiple Access (WCDMA) signals at varying power levels. The simulation results verify the efficacy of the method based on the limitations placed on the Adjacent Channel Power Ratio (ACPR) and Normalized Mean Square Error (NMSE).