基于一种新预失真结构的记忆多项式模型

Memory Polynomials of a Novel Predistorter Structure

利用记忆多项式模型来建模预失真和功放的非线性特性,可以不受特定功放模型的约束,具有较好的健壮性。提出了一种新结构的预失真模型,阐述了功放和预失真模型在数学上的关联。由一组功放的输入-输出信号,不难求出预失真器的记忆多项式;仿真结果表明,经过预失真处理之后的信号减少了带外失真,并与理想的线性输出信号的频谱图几乎重合,记忆多项式模型取得了较好的效果。

Power amplifier （ PA） memory effects cannot be ignored in wideband applications.The nonlinearity of PA, as well as predistorter, can be constructed using memory polynomials for the benefits of regardless of particular model of PA, hence it is robust.A new structure of predistorter was proposed to illustrate the mathematical relationship between the PA and predistort-er.With a series of input-output signals, the memory polynomial formula of predistorter was easy to be obtained.Simulation re-sults show that output signals with predistortion can get a better out-band suppression close to the ideal linear output signals;this indicates memory polynomial model works well.