A non-cooperative underwater acoustic pulse signal detection method based on the improved fractional Fourier transform (Frft) power spectral entropy

Abstract Non-cooperative underwater acoustic pulse signal detection, which often lacks prior information, typically employs energy detection methods. However, in low signal-to-noise ratio (SNR) conditions, the efficiency of this method significantly decreases. To address this issue, this paper proposes a method for underwater target detection based on the improved fractional-order power spectral entropy. In underwater acoustic pulse signals, common types include CW (Continuous Wave) signals and LFM (Linear Frequency Modulation) signals. After the fractional Fourier transform, the energy of the signals becomes concentrated. We raise the signal energy to the power of v and then calculate its entropy value. Simulation results show that the proposed method can reliably detect the existence of pulsed signals under complex noise backgrounds.