An adaptive digital predistorter with iterative noise cancelation

In this paper, we propose a linearization technique combined with an iterative noise cancelation. This method alleviate the effect of added noises which prevent a predistorter (PD) from estimating the exact characteristics of power amplifier (PA). To iteratively cancel the noise included in the feedback signal, the output signal of power amplifier without noise is reconstructed by applying the inverse characteristic of PD to the predistorted signals, then the noise can be revealed by subtracting the reconstructed signals from the feedback signals. Simulation results based on the mean-square error (MSE) and power spectral density (PSD) criteria to evaluate PD performance is presented. The results show that the iterative noise cancelation method significantly enhances the MSE performance, which leads to an improvement of the out-of-band power suppression.