PREDISTORTION CIRCUIT, WIRELESS COMMUNICATION UNIT AND METHOD FOR COEFFICIENT ESTIMATION

摘要

A predistortion circuit is for providing distortion correction in a presence of harmonics. The predistortion circuit includes an input for receiving a digital input signal; an output for providing a digital output signal to an up-conversion element that produces harmonic terms operably coupled to a non-linear device; and a processor operably coupled to an output of the non-linear device for receiving an output radio frequency signal therefrom and arranged to determine a digital correction to be applied to the digital input signal. The processor is further arranged to determine the digital correction that includes a plurality of in-phase and quadrature cross-terms of the digital input signal where terms of a same order have different co-efficients.