北斗卫星B2信号数字预失真补偿方法研究  

Research on digital pre-distortion compensation method of BDS B2 signal

作　　者：刘瑞 贺成艳 张小贞 白燕[1,2] LIU Rui;HE Chengyan;ZHANG Xiaozhen;BAI Yan(National Time Service Center,Chinese Academy of Sciences,Xi’an 710600,China;School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 101408,China;School of Electronics and Information,Northwestern Polytechnical University,Xi’an 710129,China)

机构地区：[1]中国科学院国家授时中心,陕西西安710600 [2]中国科学院大学天文与空间科学学院,北京101408 [3]西北工业大学电子信息学院,陕西西安710129

出　　处：《系统工程与电子技术》2024年第11期3827-3834,共8页Systems Engineering and Electronics

基　　金：国家自然科学基金(12273046)资助课题。

摘　　要：针对北斗星上信号发射通道中高功放和滤波器引起的导航信号非线性失真问题,提出间接学习结构的数字预失真用以补偿导航信号产生的非线性失真。通过采用带宽最大的非对称恒包络二进制偏移载波(asymmetric constant envelope binary offset carrier,ACE-BOC)调制的北斗B2信号,验证数字预失真对补偿导航信号非线性失真的有效性及可行性,并从调制星座、功率谱、相关函数、S曲线过零点偏差等信号评估指标对数字预失真处理前后的信号进行对比分析。实验结果表明,数字预失真可以有效抑制20 dB的带外功率损失,相关损失可由0.7 dB下降到0.009 dB以及S曲线过零点偏差由0.88 ns下降到0.0029 ns。本文所提的数字预失真模型可有效改善信号发射通道引起的信号非线性失真。Aiming at the navigation signal nonlinear distortion problem caused by the high amplifier and filter of the signal transmitting channel to the BeiDou satellite,a digital pre-distortion with indirect learning structure to compensate for the nonlinear distortion generated by the navigation signal is proposed.The effectiveness and feasibility of digital pre-distortion in compensating the nonlinear distortion of navigation signals is verified by using the BeiDou B2 signal modulated by asymmetric constant envelope binary offset carrier(ACE-BOC)with the largest bandwidth,and the signals before and after digital pre-distortion processing are compared and analyzed from several aspects,such as modulation constellations,power spectra,correlation functions,and S-curve bias.Experiment results show that the digital pre-distortion can effectively suppress the out-of-band power loss of 20 dB,the correlation loss can be reduced from 0.7 dB to 0.009 dB and the S-curve bias can be reduced from 0.88 ns to 0.0029 ns.The proposed digital predistortion model can effectively improve the nonlinear distortion caused by the signal transmission channel.

关 键 词：北斗卫星导航系统 B2信号 高功率放大器 数字预失真 信号质量评估 

分 类 号：TN911.6[电子电信—通信与信息系统]