超宽带信号数字预失真时延补偿算法  

Digital Pre-distortion Time Delay Compensation Algorithms for Ultra Wideband Signals

作　　者：赵林军[1,2] 张海林 王方[3] ZHAO Linjun;ZHANG Hailin;WANG Fang(School of Physics and Telecommunication Engineering,Shaanxi University of Technology,Hanzhong 723001,China;School of Telecommunications of Engineering,Xidian University,Xi’an 710071,China;The 54th Research Institute of CETC,Shijiazhuang 050081,China)

机构地区：[1]陕西理工大学物理与电信工程学院,陕西汉中723001 [2]西安电子科技大学通信工程学院,陕西西安710071 [3]中国电子科技集团公司第五十四研究所,河北石家庄050081

出　　处：《无线电工程》2023年第10期2277-2285,共9页Radio Engineering

基　　金：国家自然科学基金联合基金重点项目(U21A200915);陕西省科技厅专项委托项目(2021JCW15)。

摘　　要：数字预失真(Digital Pre-Distortion,DPD)是功率放大器(Power Amplifier,PA)线性化校正的主流技术之一。DPD两路激励信号间的时延是影响预失真算法稳定性的主要因素。针对DPD系统中信号间因采样而导致的时延模糊问题,基于最优化插值计算理论,在信号幅度互相关函数时延估计算法的基础上,提出了一种二次线性拟合的信号分数采样间隔时延估计算法。由该算法的数值分析结果可以看出,当DPD两路激励信号间的分数采样间隔时延在[-T_(s)/2,+T_(s)/2]时,使用二次线性拟合分数时延估计算法所获得时延估计值与理论时延值之间的最大误差不大于0.03 T_(s)。同时,给出了具有信号时延参数的“插值”滤波器实现的DPD激励信号间的时域补偿方法,数值分析结果表明,采用所提的信号时延补偿算法可以获得不大于搜索法可实现的信号误差矢量幅度(Error Vector Magnitude,EVM)。所提算法具有易于数字化实现等优点。Digital Pre-Distortion(DPD)is one of the main techniques for linearization revise of Power Amplifier(PA).Time delay between the excitation signals of DPD is the main factor affecting the stability of pre-distortion algorithms.Based on the optimal interpolation theories and the time delay estimation algorithm of signal amplitude cross-correlation function,a time delay estimation algorithm for signal fractional sampling interval based on quadratic linear fitting is proposed to solve the problem of time delay fuzziness in DPD.According to numerical analyses results,when the fractional sampling interval delay between the two excitation signals of DPD falls within[-T_(s)/2,+T_(s)/2],the maximum error between the time delay estimation value obtained using quadratic linear fitting fractional delay estimation algorithm and the theoretical time delay value is not greater than 0.03 T_(s).At the same time,the method of using an“interpolation”filter with signal time delay parameters to implement time domain compensation between the excitation signals in DPD is discussed.Numerical analyses results show that the signal Error Vector Magnitude(EVM)obtained by using the proposed signal time delay compensation method is not greater than that obtained by using LUT method.The proposed algorithm has the advantage of easy to achieve digital implementation.

关 键 词：数字预失真 时延估计 时延补偿 插值算法 

分 类 号：TN722.7[电子电信—电路与系统]