Adaptive time-frequency representation for weak chirp signals based on Duffing oscillator stopping oscillation system

摘要

To investigate high-resolution time-frequency representations for any type of weak chirp signals with a very low signal-noise ratio, we revisit the inherent deficiencies of conventional Duffing oscillator detection methods and propose a novel Duffing oscillator stopping oscillation detection system. As a result, the detection of chirp signals can be successfully realized, and the influence of nondetection zones and critical thresholds on the detection accuracy is successfully eliminated. Furthermore, we propose an adaptive Duffing oscillator stopping oscillation detection method to measure the instantaneous frequency variation of a highly dynamic chirp signal within a large frequency range. The simulation results indicate that, compared with the conventional Duffing oscillator detection methods and the Choi-Williams distribution, the proposed method greatly expands the frequency detection range of a single Duffing oscillator and has a lower computing cost and effective real-time performance in detecting a high-precision weak chirp signal, which provides a new solution for the time-frequency representation of weak chirp signals at a lower signal-noise ration and reveals broad prospects for applications in engineering.