Systems Engineering and Electronics ›› 2023, Vol. 45 ›› Issue (1): 93-100.doi: 10.12305/j.issn.1001-506X.2023.01.12

• Sensors and Signal Processing • Previous Articles    

Laser radar signal denoising algorithm based on CEEMD combined with improved wavelet threshold

Yuzhao MA1,*, Kui LIU1, Yanfeng ZHANG1, Shuai FENG2, Xinglong XIONG1   

  1. 1. Tianjin Key Laboratory for Advanced Signal Processing, Civil Aviation University of China, Tianjin 300300, China
    2. Engineering Technical Training Center, Civil Aviation University of China, Tianjin 300300, China
  • Received:2021-05-08 Online:2023-01-01 Published:2023-01-03
  • Contact: Yuzhao MA

Abstract:

The long-distance echo signal of laser radar is affected by noise and is seriously distorted. In order to effectively remove the noise of the signal and improve the signal-to-noise ratio of the echo signal, a denoising algorithm combining complementary ensemble empirical mode decomposition (CEEMD) with an improved wavelet threshold is proposed. CEEMD can adaptively decompose nonlinear and non-stationary signals, and the improved wavelet threshold function has high-order differentiability characteristics, which can overcome the problems of hard threshold and soft threshold functions. The combination of the two methods can remove noise more effectively. Firstly, the echo signal is decomposed by CEEMD to obtain several intrinsic mode function (IMF) components. Secondly, the correlation coefficient between the IMF components and the signal is calculated by the correlation coefficient method. And the relevant and uncorrelated components are determined. Finally, the wavelet improved threshold method is used to denoise the uncorrelated components, and the rough penalty method is used to smooth the correlated components, and then the signal is reconstructed. Experimental results based on measured data show that the proposed algorithm has improved the signal-to-noise ratio by 2.65 dB and 0.58 dB compared with the CEEMD denoising method and CEEMD combined with the original improved threshold denoising method.

Key words: laser radar, signal processing, complementary ensemble empirical mode decomposition (CEEMD), wavelet threshold denoising

CLC Number: 

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