A new optimized Stockwell transform applied on synthetic and real non-stationary signals

作者：Moukadem Ali^*; Bouguila Zied; Abdeslam Djaffar Ould; Dieterlen Alain

来源：Digital Signal Processing, 2015, 46: 226-238.

DOI：10.1016/j.dsp.2015.07.003

• Time-frequency
• Stockwell transform
• Energy concentration
• Active-set algorithm
• Heart sounds

The aim of this paper is to improve the energy concentration of the Stockwell transform (S-transform) in the time-frequency domain. A modified S-transform is proposed with several parameters to control the width of a hybrid Gaussian A constrained optimization problem is proposed based on an energy concentration measure as objective function and inequalities constraints to define the bounds of the Gaussian An active-set algorithm is applied to resolve the optimization problem. The optimization of the energy concentration in the time-frequency plane can lead to more reliable applications for non-stationary signals. The simulation results show a significant improvement of the proposed methodology most notably in the presence of noise comparing with the standard S-transform and existing modified S-transform in the literature. Moreover, comparison with other known time-frequency transforms such as Short-time Fourier transform (STFT) and smoothed-pseudo Wigner-Ville distribution (SPWVD) is also performed and discussed. The proposed S-transform is tested also on real non-stationary signals through an example of split detection in heart sounds.

• 出版日期2015-11