J4 ›› 2011, Vol. 38 ›› Issue (6): 55-61.doi: 10.3969/j.issn.1001-2400.2011.06.009

• Original Articles • Previous Articles     Next Articles

Instantaneous frequency measurement method for the broadband non-stationary signal

WANG Hai1;FAN Wenjing2;ZHANG Shengfeng3
  

  1. (1. School of Mechano-electronic Engineering, Xidian Univ., Xi'an  710071, China;
    2. The 8th Institute of Shanghai Academy of Spaceflight Tech., Shanghai  200233, China;
    3. Zhejiang Vocational and Technical College, Wenzhou  325003, China)
  • Received:2010-10-18 Online:2011-12-20 Published:2011-11-29
  • Contact: WANG Hai E-mail:wanghai@mail.xidian.edu.cn

Abstract:

An instantaneous frequency measurement method for broadband non-stationary signal is presented. The signal can be decomposed into progressive single-frequency signals by added qualification adaptive filters. According to their phase functions of analytical signals, the instantaneous frequencies are obtained. By integration of time-frequency relationship of all components, the instantaneous frequencies of broadband non-stationary signal are accurately measured. Simulation and error analysis prove that this method overcomes the difficulties in instantaneous frequency measuring of Fourier analysis, Wavelet transformation and Hilbert-Huang algorithm for the broadband non-stationary signal. In the whole analyzed frequency band it can achieve a higher frequency measurement resolution and has a measurement error of less than 0.2MHz for the signals with an SNR of above 0dB . For 8μs long signal, this method has a better real-time processing capability, but an initial  operational delay of 25.816μs. Therefore, this method can meet the requirements of instantaneous frequency measurement for the broadband non-stationary signal.

Key words: broadband non-stationary signal, instantaneous frequency measurement, adaptive filtering, hilbert transformation, error analysis

CLC Number: 

  • TN91