Volterra series based predistortion for broadband RF poweramplifiers with memory effects

RF power amplifiers (PAs) are usually considered as memoryless devices in most existing predistortiontechniques. However, in broadband communication systems, such as WCDMA, the PA memory effects are significant, and memoryless predistortion cannot linearize the PAs effectively. After analyzing the PA memory effects, a novelpredistortion method based on the simplified Volterra series is proposed to linearize broadband RF PAs withmemory effects. The indirect learning architecture is adopted to design the predistortion scheme and the recursiveleast squares algorithm with forgetting factor is applied to identify the parameters of the predistorter. Simulationresults show that the proposed predistortion method can compensate the nonlinear distortion and memory effectsof broadband RF PAs effectively.