Fast adaptive predistortion lineariser using polynomial functions

Adaptive predistortion is an effective method for linearising high power amplifiers. An important problem faced in the optimisation of a predistortion lineariser is that of convergence into a local minimum. A global optimisation algorithm is presented which uses polynomial predistortion and postdistortion. By using postdistortion of the demodulated signals, objective functions of quadratic shape are obtained and fast convergence to the global minimum is ensured. Computer simulation results are presented which show fast convergence and high spectral improvement.<>