A Robust Power Amplifier Predistorter Constructed Using Memory Polynomials

A robust memory polynomial predistorter for power amplifier nonlinear compensation in OFDM system is proposed in this paper. The memory polynomial for the predistorter design is equivalent simplification of volterra series. This paper gives the indirect learning architecture and generalised normalised gradient descent (GNGD) algorithm for polynomial coefficient estimation. Computer simulations show that the proposed predistorter is very robust. It can overcome the initial parameter sensitive problem that exists in the predistorter using normalized least mean square (NLMS) algorithm. The proposed predistorter also gets a better linearization performance than the predistorter using NLMS algorithm. The predistorter is still easy to be implemented with a relatively higher computational complexity.