为了能够对记忆型功率放大器线性化处理,并能一定程度克服其记忆效应,该文介绍一种自适应数字预失真器。该数字预失真器采用查找表与记忆效应补偿技术相结合的方法,并且利用内插值方法有效减小了查找表幅度量化过程产生的误差。相比记忆多项式预失真器,这种预失真器的计算复杂度较小,却能够得到与其相近的线性化效果。基于功率放大器记忆多项式模型,利用OFDM(Orthogonal Frequency Division Multiplexing)宽带信号验证该文提出的预失真器对记忆型非线性功率放大器的良好线性化效果。
To obtain the good performance for linearization,a digital predistortion algorithm is presented.Look-Up-Table(LUT) and memory-effect compensation techniques is combed,and the linear interpolation method is applied to the LUT.Compared to memory polynomial methods,this predistortion technique can reduce the complexity of calculation and obtain the good performance for linearization.Under power amplifier's memory polynomial model,the simulation results for Orthogonal Frequency Division Multiplexing(OFDM) wideband signal show the excellent linearization purpose for memory nonlinear power amplifier.