Systems Engineering and Electronics ›› 2021, Vol. 43 ›› Issue (8): 2116-2123.doi: 10.12305/j.issn.1001-506X.2021.08.12

• Sensors and Signal Processing • Previous Articles     Next Articles

Bispectrum feature recognition of radar signal based on entropy evaluation and modal decomposition

Xinping MI, Xihong CHEN*, Zan LIU, Yongjin LIU, Qiang LIU   

  1. Air and Missile Defense College, Air Force Engineering University, Xi'an 710051, China
  • Received:2020-07-01 Online:2021-08-01 Published:2021-08-05
  • Contact: Xihong CHEN

Abstract:

In order to solve the problems of low accuracy and poor anti-noise of radar signal modulation recognition under low signal to noise ratio (SNR), a recognition method based on entropy evaluation modal decomposition and bispectrum feature extraction is proposed. Based on the characteristics of bispectrum which can suppress Gaussian noise, the feasibility of signal modulation recognition in low SNR is analyzed and the noise term is introduced. Due to the interference of noise term, the noise suppression effect of bispectrum below 0 dB becomes worse. An empirical modal decomposition based on information entropy evaluation is proposed to preprocess the signal and improve the SNR. Finally, a convolutional neural network classifier is designed to recognize different modulation signals. Simulation experiment results show that this method has better anti-noise performance than the traditional method, and can effectively identify different types of signals in low SNR.

Key words: bispectrum, information entropy, convolutional neural network, empirical modal decomposition

CLC Number: 

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