自适应宽带数字预失真理论分析和仿真  

TheoreticaI Analysis and Simulation of Adaptive Wideband Digital Predistortion

作　　者：齐帅[1] 严家明[1] 杨亚光[2] 张浩[3] 

机构地区：[1]西北工业大学,陕西西安710129 [2]湖南大学,湖南长沙410082 [3]中国科学院微电子研究所,北京100029

出　　处：《计算机仿真》2011年第10期99-102,共4页Computer Simulation

基　　金：国家863计划(2009AA011606)

摘　　要：研究优化宽带性能问题,在多载波调制系统中,具有较大峰均比的宽带线性调制信号经过射频功率放大器会产生非线性失真和记忆效应。为了消除功放非线性带来的影响,提出了宽带自适应数字预失真技术,采用间接学习结构设计预失真系统,记忆多项式模型进行功放辨识,并运用递推最小二乘算法更新预失真器参数。仿真结果表明,预失真器改善带外频谱抑制25dB左右,有效地补偿了功放的非线性失真和记忆效应,提高了功放效率,对通信传输质量有了提高,并为优化设计提供了参考。Nonlinear distortion and memory effects were resulted from multi-carrier modulation when the linear modulated signals with high peak-to-average power ratio and wideband got through the high power amplifier.An adaptive digital predistortion techinque has been applied to eliminate distortion caused by nonlinear amplifier.The indirect learning architecture was adopted to design the predistortion system,the memory polynominal model was used for power amplifier identification and the recursive least squares algorithm was applied to refresh the parameters.Simulated and experimental results show that the proposed digital predistorter can suppress spectral regrowth by 25dB,which compensates PA＇s nonlinear distortion and enhance PA＇s efficiency.It will be helpful to the utility development of transmitter＇s amplifier linearization.

关 键 词：功率放大器 数字预失真 间接学习 递推最小二乘法 

分 类 号：TN914[电子电信—通信与信息系统]