Journal of Xidian University

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Non-linear frequency modulated signal decomposition based on the improved chirplet time-frequency atom

GUO Pengcheng1;WANG Xing1;CHENG Siyi1;WANG Feng2   

  1. (1. Aeronautics and Astronautics Engineering College, Air Force Engineering Univ., Xi'an 710038, China;
    2. Air Force Area Military Representatives Bureau in Shanghai, Shanghai 200000, China)
  • Received:2017-01-08 Online:2018-02-20 Published:2018-03-23

Abstract:

Regarding the deficiencies that the Chirplet time-frequency atom has weak decomposition performance to non-linear frequency modulation signal of a sine type, an improved Chirplet atom (IChirplet) is proposed. First, it is analyzed that the Chirplet atom has a mismatch with time-frequency distribution of the non-linear signal. Then, a sine frequency modulation factor is introduced into the Chirplet atom to make the atom time-freqency curve have sine similarity bending performance. Finally, the matching pursuit algorithm is replaced by the genetic algorithm to improve the efficiency of atom searching. Simulation results show that the improved Chirplet atom has better decomposition performance to the non-linear frequency modulated signal compared with the Gabor, Chirplet, and FMmlet atom.

Key words: time-frequency atom, non-linear frequency modulated signal, time-frequency distribution, genetic algorithm