一种新的并联两箱功率放大器模型

摘要

This paper presents a novel parallel two-box model for power amplifier (PA) by replacing envelope memory polynomial (EMP) model with simplified cross items between memory times (CIMT) model in hybrid MP-EMP(HME)model.Because the EMP considers only the effects of signals between current times and memory times and without the cross items between memory times,and so it cannot describes the memory effect of the PA fully.The proposed model obtains better results with low complexity at the same order of nonlinearity and memory depth.When the nonlinearity order is 3 and the memory depth is 2,the number of coefficients of the proposed model is 16.67％ less than that of the HME model,while the normalized mean square error (NMSE) is improved to 1.13 dB.When applied to digital predistortion,the adjacent channel power ratio (ACPR) of it is18.63％ higher than that of the HME model,which greatly enhance the power amplifier performance and predistortion effects.%针对功率放大器HME(Hybrid MP-EMP)模型的子模型EMP(Envelope Memory Polynomial)模型只考虑了当前时刻与记忆时刻信号间的相互影响,没有考虑记忆时刻信号间的交叉影响,对功率放大器记忆效应描述不充分.该文用简化了的CIMT模型代替EMP模型,提出了一种新的并联两箱功放模型.采集实际功率放大器的输入输出信号,分别用HME模型和该文提出的模型对功率放大器进行建模.仿真结果表明,在相同的非线性阶数和记忆深度条件下,本文模型总能以较低的复杂度取得更高的建模效果.当模型非线性阶数为3,记忆深度2为时,本文模型比HME模型系数数量减少了16.67％,归一化均方误差却能改善达1.13 dB,将该模型应用到数字预失真中,相邻信道功率比比HME模型提高了18.63％,极大地提升了功放建模性能与预失真效果.