FAST ADAPTIVE PREDISTORTION LINEARISER USING POLYNOMIAL FUNCTIONS

Adaptive predistortion is an effective method for linearising high pow er amplifiers. An important problem faced in the optimisation of a pre distortion lineariser is that of convergence into a local minimum. In the Letter, a global optimisation algorithm is presented which uses po lynomial predistortion and postdistortion. By using postdistortion or the demodulated signals, objective functions of quadratic shape are ob tained and fast convergence to the global minimum is ensured. Computer simulation results am presented which show fast convergence and high spectral improvement.