Concurrent dual band digital predistortion using look up tables with variable depths

A concurrent dual band predistorter implementation using look up tables is presented in this paper. The power amplifier introduces the main source of nonlinearity in a transmitter chain; and the distortion is further enhanced when sending signals in multiple carrier frequencies. Using a dual band predistorter based on a memory polynomial model allows for the compensation of these nonlinearities by taking into account both signals. Converting the coefficients to look up tables reduces the number of arithmetic operations needed in a signal processor. Results are presented with the conventional dual band predistorter and the look up table predistorter in operating bands 880 MHz and 2140 MHz, showing the linearization capability and accuracy with the proposed implementation agrees with the conventional predistorter.