Training Sample Acquisition Strategy Based Digital Pre-distortion

Digital pre-distortion (PD) is a promising technique for power amplifier (PA) linearization and efficiency enhancement. Parameter estimation for both PA and PD models are quite important in all pre-distortion schemes. In this paper we introduce the concept of RCBL (Region Can Be Linearized) and highlight the difference of training sample acquisition strategies (TSAS) for three different pre-distortion schemes. We prove that the improper samples may lead to the inaccuracy of the coefficients, or even an error. Thus we propose to choose the PA modeling and inverse structure as our scheme to do the DPD construction. A 5MHz Wimax signal sampled from a real PA is used to do the loop delay estimation, the PA model identification and the PD construction. Simulation results show that the AM/AM, AM/PM characteristics have been improved much and more than 15 dB of ACPR (Adjacent Channel Power Ratio) has been achieved.