Effects of even-order terms on behavior models in predistortion linearization

Power amplifier (PA) is indispensable in wireless communication systems and is nonlinear inherently. Many mathematical model and analytical approach has been used to analysis the nonlinear character of PA and to construct the model of predistorter. However, most of the models contain only odd order terms to analysis PA nonlinearity. Some researches show that only odd-order polynomial terms in the PA nonlinearity impact a bandpass communication signal. Few researches have attempted to study the behavior of odd-even terms in nonlinear modeling and how it impacts the system performance. Researches on odd-even terms behavior and the nature of their influence are very significant. Therefore, we evaluated the effects of adding even-order terms from mathematical view to prove their effectiveness. The theoretical analysis shows that odd-even polynomial terms contain infinite number of odd-order components. The simulation results verify the validity of this conclusion.