A digital predistortion method based on nonuniform memory polynomial model using interpolated LUT

This paper presents a baseband Digital PreDistortion (DPD) method for Power Amplifier (PA) linearization. It is based on the nonuniform Memory Polynomial (MP) model with direct learning architecture. The interpolated Look-Up Table (LUT) is adopted in the predistorter, to replace a part of the computational operations. The complex predistorted signal is calculated by two parts: one is the amplitude of the predistorted signal which is obtained by a linear-interpolation LUT; the other is the phase of the predistorted signal which is obtained by a quadratic-interpolation LUT. The proposed method makes a good tradeoff between the computational complexity, table size and linearization performance. It is validated on a test bench using a PA ZFL- 2500 driven by a 64QAM modulated signal.