A novel digital predistortion technique for adaptive predistorter applications

This paper presents a novel predistortion technique for a Radio Frequency (R-F)/Microwave power amplifier (PA). To model the nonlinear system, an infinite impulse response (IIR) model is proposed. By sampling the both transmitter system input and output, the low order IIR coefficients can be easily extracted. The IIR model of the system is then use for designing predistorter. As a result, the proposed predistortion technique can offer reduced nonlinear distortion with a simple computation process, which is important for real time adaptive predistortion system. Power spectra of the transmitter system using this proposed linearlizer are examined using two-tone, multi-tone and digitally modulated 16-quadrature amplitude modulation (QAM) signals. Details of the proposed predistortion technique are described, and the simulation results are presented and discussed.