一种基于记忆LUT的多倍频程预失真方案

针对多载波无线通信系统中多倍频程功率放大器存在的强非线性失真与记忆效应失真问题,提出了一种基于记忆查找表的LUT+MP多倍频程预失真方案。方案模型由记忆查找表(LUT)和记忆多项式(MP)串联构成,采用间接学习法的LMS和RLS算法对模型参数训练辨识。仿真结果表明,针对维纳模型高功率放大器,在输出功率回退OBO=2.27 d B时,对Wiener模型功放的三阶互调失真改善达到了55.9 d B,五阶互调失真改善达到了44.5 d B。与现有的LUT+FIR和LUT+并联FIR预失真方案相比较,能带来更好的建模精度和线性化效果。同时,设计使用的学习算法简单实用,稳定性能好。

A LUT-based Pre-distortion Schemefor the Multi-octave Power Amplifier

For the problem of strong nonlinear distortion and memory effect distortion of multi-octave power amplifier, this seriously affects the performance of communication system in the current multi-carrier wireless communication system. In this paper, a new LUT MP multiple octave pre-distortion scheme based on look-up table is proposed, in which the scheme model constitutes a memory LUT and a memory polynomial in series. By using LMS and RLS algorithm of indirect learning method to train and identify the model parameters. The simulation results show, under the conditional of OBO=2.27dB with Wiener model high power amplifier, this design scheme can improve the third-order intermediations distortion by 55.9dB and the fifth-order intermediations distortion by 44.5dB.Compared with the existing pre-distortion scheme such as LUT FIR and LUT FIR in parallel, LUT MP multiple octave pre-distortion scheme can acquire better model accuracy and linear effect. Meanwhile,the learning algorithm this paper used to design is simple and practical, also has a good stability.