Adaptive digital predistortion for the power amplifiers based on look-up table with tanh as a nonlinear indexing function

This paper presents performance results of DPD using the nonlinear indexing function based on tanh. Three DPDs characterized by different indexing functions use the same estimation algorithm. However, among these methods, the tanh indexing method provides the best performance for linearization. Under the condition of 0 dB input back-off, the proposed indexing scheme performs more linearization and faster estimation compared with others. Apoint to be more important is that it can be achieved by realizing a better index function for further optimizing the performance of power amplifiers.