Piecewise Complex Circular Approximation of the Inverse Characteristics of Power Amplifiers for Digital Predistortion Techniques

This paper deals with the linearization of power amplifier characteristics by digital predistortion technique. A new approach for the implementation of the memoryless digital predistorter (PD) is proposed. It consists on using a Look-Up-Table with few entries corresponding to large step segmentation of the amplitude range of the baseband input signal. A new modeling approach was also presented. For every segment, a complex circular model was used to approximate the inverse AM/AM and AM/PM characteristics of the PA. The performance of this new modeling approach is evaluated through computer simulations.