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浙江大学学报(工学版)
Journal of ZheJiang University (Engineering Science)  2025, Vol. 59 Issue (8): 1727-1737    DOI: 10.3785/j.issn.1008-973X.2025.08.020
    
High dynamic fast acquisition algorithm for low orbit satellite spread spectrum communication system
Zhaobin XU1,2,3(),Zhiqiang XIE1,Xinbo YUAN1,Xiaojun JIN1,2,3,Zhonghe JIN1,2,3
1. Micro-satellite Research Center, Zhejiang University, Hangzhou 310027, China
2. Huanjiang Laboratory, Zhuji 311899, China
3. Key Laboratory of Micro-satellite Research of Zhejiang Province, Hangzhou 310027, China
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Abstract  

An improved FFT-IFFT acquisition algorithm was proposed aiming at the problems of low SNR and large Doppler frequency offset in low orbit satellite spread spectrum communication system. The sideband information of the swept frequency interval was used to estimate the acquisition interval, which can reduce the number of FFT and shorten the acquisition time under high sensitivity and high dynamic conditions. The probability of false acquisition was reduced and the reliability of the algorithm was improved combined with the acquisition mechanism assisted by digital automatic gain control (AGC). Theoretical analysis and experiments showed that the improved algorithm was better than traditional algorithms. The maximum sensitivity can reach ?130 dBm, the total Doppler frequency offset acquisition range can reach 140 kHz, and the acquisition time is as low as 0.8 s when the detection probability is greater than 99%, the minimum CNR is 34.66 dB and the minimum SNR is 16 dB, which meets the needs of practical application. The improved algorithm had been applied in a large-scale low orbit satellite constellation independently developed by Zhejiang University.

Key words： low orbit satellite      acquisition algorithm      Doppler frequency offset      high sensitivity      high dynamic     
Received: 10 July 2024      Published: 28 July 2025
CLC:  TN 927  
Fund:  国家自然科学基金资助项目（U21A20443，62073289）.
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Zhaobin XU
Zhiqiang XIE
Xinbo YUAN
Xiaojun JIN
Zhonghe JIN
Cite this article:

Zhaobin XU,Zhiqiang XIE,Xinbo YUAN,Xiaojun JIN,Zhonghe JIN. High dynamic fast acquisition algorithm for low orbit satellite spread spectrum communication system. Journal of ZheJiang University (Engineering Science), 2025, 59(8): 1727-1737.

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https://www.zjujournals.com/eng/10.3785/j.issn.1008-973X.2025.08.020     OR     https://www.zjujournals.com/eng/Y2025/V59/I8/1727


用于低轨卫星扩频通信系统的高动态快捕算法

针对低轨卫星扩频通信系统信噪比较低且多普勒频偏较大的问题，提出改进的FFT-IFFT捕获算法. 利用扫频区间的边带信息估计捕获区间，在高灵敏度高动态条件下减少FFT次数并缩短捕获时间. 结合数字自动增益控制(AGC)辅助的捕获机制降低误捕概率，提升了算法的可靠性. 理论分析与实验表明，改进算法比传统算法更有优势，在满足检测概率大于99%、最小载噪比为34.66 dB、最小信噪比为16 dB的情况下，极限灵敏度可达?130 dBm，总多普勒频偏捕获范围可达140 kHz，捕获时间低至0.8 s，满足实际应用的需求，已应用于浙江大学自主研制的某大规模低轨卫星星座中.


关键词： 低轨卫星,  捕获算法,  多普勒频偏,  高灵敏度,  高动态 
Fig.1 Spread spectrum communication system
Fig.2 Principle of FFT-IFFT capture algorithm
Fig.3 Grouping parallel FFT-IFFT capture algorithm
Fig.4 Interval distribution of acquisition algorithm
Fig.5 Edge band interval variation curve
Fig.6 Capture probability density function
Fig.7 Digital AGC gain curve
Fig.8 Diagram of algorithm comparison
Fig.9 Calculation frequency curve of FFT-IFFT group
Fig.10 Comparison curve of frequency sweep times
Fig.11 Rice probability density curve
Fig.12 Capture probability and signal-to-noise ratio curve
参数数值参数数值
${n_{\mathrm{B}}}$2${\text{DO}}{{\text{P}}_{\text{R}}}/{\mathrm{kHz}}$$ \pm 70$
${\text{p}}{{\text{n}}_{\text{r}}}/{\mathrm{MHz}}$$6.138$$T/{\mathrm{s}}$$ < 0.8$
${n_{\mathrm{F}}}$$1\;024$${P_{{\mathrm{FA}}}}$$ < {10^{ - 4}}$
$V$$512$${P_{{\mathrm{FD}}}}$$ < {10^{ - 2}}$
${\text{FF}}{{\text{T}}_{{\text{NUM}}}}$$11$$\delta ({f_{\mathrm{e}}})/{\mathrm{dB}}$$ < 2$
$(0.5{T_{\mathrm{h}}}\sigma _{\mathrm{n}}^{-2})/{\mathrm{dB}}$$13.9$${\text{SNR}}/{\mathrm{dB}}$$ > 16$
${\text{FF}}{{\text{T}}_{\text{R}}}/{\mathrm{Hz}}$$1\;360$${P_{\min }}/{\mathrm{dBm}}$$ > - 136.34$
${f_{\mathrm{D}}}/{\mathrm{(kbit·s^{-1})}}$$1.0\sim 2.0$$H/{\mathrm{km}}$490
${f_{\mathrm{B}}}$S-Band——
Tab.1 Parameter of spread spectrum communication system
Fig.13 Relationship between acquisition peak and frequency offset code offset
Fig.14 Acquisition of edge band interval
Fig.15 Capture result under different signal-to-noise ratio
Fig.16 Difference result of edge band interval
Fig.17 Linear error of differential result
Fig.18 Waveform of hardware simulation acquisition process
Fig.19 RF front-end hardware circuit
Fig.20 Structure of hardware testing platform
Fig.21 Actual spread spectrum communication platform
Fig.22 Comparison of false capture situation of algorithm
Fig.23 Unfolding waveform at different inlet power
算法${\text{DO}}{{\text{P}}_{\text{R}}}/{\mathrm{kHz}}$$T/{\mathrm{s}}$${f_{\mathrm{D}}}/{\mathrm{Hz}}$fmin/dB
传统算法$ \pm 70$$ < 1.2$$1.0\sim 2.0$?128
改进算法$ \pm 70$$ < 0.8$$1.0\sim 2.0$?130
Tab.2 Performance metrics comparison of acquisition algorithm
P/dBme/10?6
传统算法改进算法
$ - 130$$32$$4.74$
$ - 129$$ 55.6 $$6.09 $
$ - 128$$3.10$$2.67$
$ - 127$$3.68 $$2.41 $
$ - 126$$1.09$$1.86$
Tab.3 Comparison of error rate result of acquisition algorithm
[1]   吴树范, 王伟, 温济帆, 等 低轨互联网星座发展研究[J]. 北京航空航天大学学报, 2024, 50 (1): 1- 11
WU Shufan, WANG Wei, WEN Jifan, et al Review on development of LEO Internet constellation[J]. Journal of Beijing University of Aeronautics and Astronautics, 2024, 50 (1): 1- 11
[2]   姜春晓, 王佳蔚 高动态卫星DSSS信号Turbo迭代捕获算法[J]. 通信学报, 2021, 42 (8): 15- 24
JIANG Chunxiao, WANG Jiawei Turbo iterative acquisition algorithm for satellite high-mobility DSSS signal[J]. Journal on Communications, 2021, 42 (8): 15- 24
[3]   王康, 梁晟溟, 董启甲, 等 一种低轨卫星高灵敏度辅助定位服务系统[J]. 宇航学报, 2022, 43 (4): 445- 453
WANG Kang, LIANG Shengming, DONG Qijia, et al A high sensitivity auxiliary positioning service system using LEO satellites[J]. Journal of Astronautics, 2022, 43 (4): 445- 453
[4]   柳春. 基于PMF-FFT的高动态导航信号捕获设计与实现[D]. 成都: 电子科技大学, 2014.
LIU Chun. Design and implementation of high dynamic navigation signal acquisition based on PMF-FFT algorithm [D]. Chengdu: University of Electronic Science and Technology, 2014.
[5]   韩志凤, 刘建业, 李荣冰, 等 基于差分相关积分的北斗弱信号快速捕获方法[J]. 中国惯性技术学报, 2016, 24 (6): 815- 820
HAN Zhifeng, LIU Jianye, LI Rongbing, et al Fast acquisition of Beidou weak signal based on differential correlation[J]. Journal of Chinese Inertial Technology, 2016, 24 (6): 815- 820
[6]   郭晓旭, 徐兆斌, 成恒飞, 等 用于星间通信的高灵敏度快捕算法[J]. 哈尔滨工业大学学报, 2023, 55 (8): 43- 50
GUO Xiaoxu, XU Zhaobin, CHENG Hengfei, et al High sensitivity fast acquisition algorithm for inter-satellite communication[J]. Journal of Harbin Institute of Technology, 2023, 55 (8): 43- 50
doi: 10.11918/202208112
[7]   张朝杰, 金小军, 杨伟君, 等 高灵敏度微小卫星可变带宽接收机设计[J]. 浙江大学学报: 工学版, 2011, 45 (4): 660- 664
ZHANG Chaojie, JIN Xiaojun, YANG Weijun, et al Design of variable loop bandwidth high sensitivity micro-satellite receiver[J]. Journal of Zhejiang University: Engineering Science, 2011, 45 (4): 660- 664
[8]   CUI S, WANG D, HOLTKAMP B, et al. A multi-frequency acquisition algorithm for a GNSS software receiver [C]//IEEE International Geoscience and Remote Sensing Symposium. Valencia: IEEE, 2018: 1082-1085.
[9]   陈延涛, 董彬虹, 李昊, 等 一种高动态低信噪比环境下基于多样本点串行快速傅里叶变换的信号捕获方法[J]. 电子与信息学报, 2021, 43 (6): 1691- 1697
CHEN Yantao, DONG Binhong, LI Hao, et al A signal acquisition method based on multi-sample serial fast Fourier transform in high dynamic and low SNR environment[J]. Journal of Electronics and Information Technology, 2021, 43 (6): 1691- 1697
doi: 10.11999/JEIT200149
[10]   孙振辉. 高动态低信噪比条件下DSSS信号接收机捕获技术的研究[D]. 西安: 西安电子科技大学, 2020.
SUN Zhenhui. Research on acquisition process of DSSS receiver under high dynamic and low SNR circumstances [D]. Xi'an: Xidian University, 2020.
[11]   冯永新, 任锦君, 刘芳 双块零扩展截断相关的长码信号快速捕获算法[J]. 兵工学报, 2019, 40 (3): 539- 547
FENG Yongxin, REN Jinjun, LIU Fang A fast acquisition algorithm with DBZP truncation correlation for the long code signal[J]. Acta Armamentarii, 2019, 40 (3): 539- 547
[12]   朱超逸. 高可靠小型测控应答机的研究与改进[D]. 杭州: 浙江大学, 2015.
ZHU Chaoyi. A research and development of a high reliability micro TT and C Transponder [D]. Hangzhou: Zhejiang University, 2015.
[13]   HE Y, SHI X, WANG Y, et al Intelligent search strategy for Doppler frequency based on fuzzy logic in DSSS signal acquisition[J]. IEEE Transactions on Aerospace and Electronic Systems, 2023, 59 (4): 4709- 4720
doi: 10.1109/TAES.2023.3234456
[14]   莫杭斌. 微纳卫星星间链路可靠通联设计与实现[D]. 杭州: 浙江大学, 2020.
MO Hangbin. Design and implementation of reliable communication in inter-satellite link of micro-nano satellites [D]. Hangzhou: Zhejiang University, 2020.
[15]   熊竹林, 安建平 一种低复杂度的低信噪比非相干直扩信号捕获算法[J]. 电子学报, 2016, 44 (4): 753- 760
XIONG Zhulin, AN Jianping A low complexity acquisition algorithm for DSSS signal with low SNR and non-coherent data modulation[J]. Acta Electronica Sinica, 2016, 44 (4): 753- 760
[16]   鲁郁. 北斗/GPS双模软件接收机原理与实现技术[M]. 北京: 电子工业出版社, 2016.
[17]   JIN G, ZHUANG Y, CUI M, et al A stable and two-step settling digital controlled AGC loop for GNSS receiver[J]. IEICE Electronics Express, 2014, 11 (19): 738- 744
[18]   ZHANG S, WAN G, WANG S, et al. A fast DSSS signal acquisition method with low computing load based on approximate kernel FFT/IFFT [C]// Asia-Pacific Conference on Communications Technology and Computer Science. Shenyang: IEEE, 2023: 319-323.
[19]   韩航程, 刘井龙, 梁丹丹, 等 基于FFT的高数据率低信噪比下的长码直捕算法[J]. 北京理工大学学报, 2016, 36 (9): 976- 982
HAN Hangcheng, LIU Jinglong, LIANG Dandan, et al Long code direct acquisition algorithm of DSSS signals based on FFT in high rate and low SNR condition[J]. Journal of Beijing Institute of Technology, 2016, 36 (9): 976- 982
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