A fast algorithm for digital pre-distortion of nonlinear power amplifiers

A fast iterative algorithm for pre-equalisation of a nonlinear dynamic (with memory) system is presented. The algorithm is based on the secant method for root-finding. Within a few iterations the nonlinear and dynamic effects of the system, modelled, e.g., with a Volterra or Wiener model, can be compensated very well. The algorithm is then used to linearise a nonlinear power amplifier, modelled as a Wiener system. Measurement results prove the excellent performance of the presented method.