低轨卫星高动态信号捕获算法研究  

Research on high dynamic signal acquisition algorithm of low Earth orbit satellite

作　　者：都文杰 荆文芳[1,2] 陈校非 卢晓春 邹德财[1,2] DU Wen-jie;JING Wen-fang;CHEN Xiao-fei;LU Xiao-chun;ZOU De-cai(National Time Service Center,Chinese Academy of Sciences,Xi’an 710600,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院国家授时中心,西安710600 [2]中国科学院大学,北京100049

出　　处：《时间频率学报》2023年第2期150-160,共11页Journal of Time and Frequency

基　　金：国家自然科学基金资助项目(E007ZK1701)。

摘　　要：低轨卫星数量呈井喷式增长,未来低轨卫星天基测控将是提升海量卫星管控能力的有效手段。针对低轨卫星星载终端接收天基测控信号时面临卫星运动速度快、多普勒频率大、可视时间短等因素引起的信号快速捕获难题,论文研究了PMF-FFT(partial match filter-fast Fourier transform)高动态捕获算法对低轨卫星系统的适用性,分析了捕获多普勒范围的决定因素,捕获对信噪比的要求,以及平均捕获时间的相关因素,并通过Matlab仿真进行验证。结果表明,在信噪比-25 dB以上时,能够捕获到多普勒频移为95 kHz的信号,平均捕获时间在200 ms以内。针对不同信号体制和多普勒频率,需要调整匹配滤波器长度和FFT点数,该捕获算法适用于低轨卫星星载终端。The number of LEO(low Earth orbit)satellites is growing in a blowout.In the future,space-based measurement and control of LEO satellites will be an effective means to improve the management and control ability of massive satellites.Aiming at the problem of fast signal acquisition caused by fast satellite motion speed,large Doppler frequency and short visual time when receiving space-based signals,this paper studied the applicability of PMF-FFT(partial match filter-fast Fourier transform)high dynamic acquisition algorithm to the system,and analyzed the determinants of acquisition Doppler range,the requirements of acquisition for signal-to-noise ratio and the related factors of average acquisition time,and these were verified by Matlab simulation.The results showed that when the Doppler was 95 kHz,the SNR(signal noise ratio)was more than-25 dB,and the average acquisition time was less than 200 ms.For different signal systems and Doppler frequencies,the length of matched filter and the number of FFT points need to be adjusted.The acquisition algorithm was suitable for LEO satellite on-board terminals.

关 键 词：低轨卫星 分段匹配滤波器和快速傅里叶变换 信噪比 平均捕获时间 

分 类 号：P127.1[天文地球—天体测量]