A fast adaptive polynomial predistorter for power amplifiers

In this paper, an adaptive polynomial predistortion technique is introduced to counterbalance the AM/AM and AM/PM nonlinear effects of the transmit power amplifier. Based on a polar coordinate representation, the proposed adaptation method has low complexity and guarantees a fast rate of convergence. Simulation results on spectra, bit error rates, and intermodulation distortion show that with the polynomial predistorter, M-QAM can be used with a transmit power amplifier operating near saturation to achieve the highest power efficiency, while its transmitted spectrum and performance are kept close to those in a linear channel. The effects of the quantization are also presented