Genetic algorithm based non-polynomial LUT update method for phase-amplitude RF predistortion

This paper presents a genetic algorithm based LUT update method for a RF predistorter used for linearization of a power amplifier (PA) and suggests improvements to the basic genetic algorithm to take into account the separate phase and amplitude LUTs. The method uses a small number of parameters to find the optimal predistortion function. The parameters are interpolated to create a LUT consisting of a larger number of entries. The advantage of the method is that the parameters are easy to constraint to minimize the search space and the method is more efficient in terms of linearity than the ones based on polynomials that have been used previously. The method uses the adjacent channel power of the PA output as the parameter to be minimized and does not require prior information of the PA nonlinearity unlike previous methods