Research On Digital Pre-distortion Algorithm Based On Adaptive IIR Filter

The thesis introduces the inherent nonlinear characteristic and memory effectof the Power Amplifiers (PAs) and the related linearization technology. A popularbaseband signal-based linearization technology, called the digital pre-distortion (DPD)technology, is studied. Due to its high efficiency, strong adaptability, and low imple-mentation cost, this linearization technology has been widely used, and becomes atechnology that is suitable for the development of future communication systems.Due to the advantages of the adaptive Infinite Impulse Response (IIR) filter overthe Finite Impulse Response (FIR) filter, we apply the IIR filter in the adaptive DPDalgorithm in this thesis, so as to achieve a better compensation performance. Basedon this, the construction of the DPD model, the identification of the DPD model coeffi-cients and the design of adaptive DPD algorithm are presented. Due to the existenceof recursive terms in the IIR filters, we obtain an adaptive DPD algorithm based on theform of output errors corresponding to IIR filters, which we call the Recursive Predic-tion Error (RPE) algorithm.Finally, simulations are conducted to show the effect of the DPD compensationparameters obtained by the adaptive algorithm on the overall system performance.From the simulation results, we see that the DPD algorithm using the IIR filter canachieve a better compensation performance than that using the FIR filter, under thesame nonlinear order and memory length.