应用于卫星功率放大器线性化的自适应变步长算法研究

Research on Variable Step Size Algorithm Used in Satellite Power Amplifier Linearization

针对应用于低轨卫星放大器线性化的自适应预失真算法,提出一种改进的LMS算法,并建立步长因子μ与误差信号e(n)之间的一种新的非线性关系。该函数在误差e(n)接近零处具有缓慢变化的特性。文中还分析了新函数关系式中的a、b参数对算法收敛性能的影响。计算机仿真结果与理论分析相一致,改进的算法具有较好的收敛性能和鲁棒性。

This paper presents an improved LMS algorithm,and establishes a new nonlinear function between the step factor μ and the error signal e(n).This algorithm can be applied to the adaptive digital pre-distortion algorithm of LEO satellite amplifier.The error function e(n) has a slow change close to zero in the characteristics of the new adaptive algorithms which can overcome the deficiencies of the traditional steps in steady-state phase.In this paper a,b parameters of the new function on the convergence performance are analyzed,Computer simulation results and theoretical analysis are of the same.The improved algorithm has better convergence performance and robustness.