Adaptive Compensation for Power Amplifier Nonlinearity in the Presence of Quadrature Modulation/Demodulation Errors

This correspondence proposes techniques that jointly compensate for amplifier nonlinearity and quadrature modulation/demodulation (QM/QDM) errors. The proposed methods are derived based on the polynomial predistortion (PD) employing the indirect learning technique and do not require any additional feedback loop for QM/QDM-error compensation. Compared with the existing joint compensation technique, the proposed methods need some additional parameters to be estimated but exhibit faster convergence and better performance. The advantage of the proposed technique is demonstrated through computer simulation.