Systems Engineering and Electronics ›› 2025, Vol. 47 ›› Issue (5): 1395-1403.doi: 10.12305/j.issn.1001-506X.2025.05.02

• Electronic Technology • Previous Articles    

Parameter estimation algorithm for time-frequency difference using Savitzky-Golay filtering and cross-ambiguity function

You ZHANG1,2, Yonghui HUANG1, Zhihao LI1,3, Tianshu CUI4, Zhugang WANG1,*   

  1. 1. Key Laboratory of Electronics and Information Technology for Complex Space Systems, National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China
    2. School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
    3. School of Computer Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
    4. China Academy of Aerospace Science and Technology Innovation, Beijing 100088, China
  • Received:2024-04-23 Online:2025-06-11 Published:2025-06-18
  • Contact: Zhugang WANG

Abstract:

Aiming to address the issue of low accuracy in parameter estimates in low signal-to-noise ratio scenarios of time difference and frequency difference of small satellites in low orbit with small antenna size and small gain, and the correlation between noise affects the accuracy of parameter estimation, a joint estimation algorithm based on a combination of Savitzky-Golay (S-G) smoothing filtering and cross-ambiguity function (CAF) is proposed. Firstly, the signal is smoothed using S-G filtering to reduce noise. Then, combined with the sliding window segment processing, the high-order cumulant is used to eliminate the influence of noise caused by correlation. Finally, the time difference and frequency difference estimates are obtained by searching for the peak value of the CAF. Simulation results show that the proposed algorithm can enhance the precision of time difference estimation by 3.3% and frequency difference estimation by 1.5% compared with the second-order CAF algorithm under the condition of -5 dB signal-to-noise ratio. Therefore, the proposed algorithm can effectually enhance the precision of the estimation of parameters in non-ideal signal environments, such as low signal-to-noise ratio.

Key words: parameter estimation, Savitzky-Golay (S-G) filtering, cross-ambiguity function (CAF), higher order cumulant, sliding window

CLC Number: 

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