Cubic phase coupling analysis based on 2½-dimensional spectrum method

Cubic phase coupling is a very important topic in analyzing cubic nonlinear and multi-harmonic signals. The conventional cubic phase coupling analysis is usually by done by the trispectrum which has an enormous computational burden and inconspicuous physical meaning. In this paper a 2½-dimensional spectrum method (2½DSM) based on fourth-order cumulants is used to analyze cubic phase coupling. The performance and advantage of 2½DSM compared with the power spectrum are fully investigated and applied in feature extraction from ship-radiated noise is presented. Simulation results show that using this method to analyze cubic phase coupling possesses several advantages: small calculation burden, fast computing speed and high robustness under noise conditions. Analyzing true ship-radiated noise data shows that it can be used to discriminate different type of ships