In this paper we present two methodologies to generate heart rate variability (HRV) signals characterized by controlled and real-like time-frequency (TF) structure to be used to assess different methods of non-stationary HRV analysis. The synthesized signals are stochastic processes whose TF structure is predetermined by choosing either the time-course of the instantaneous frequencies and power...

In order to improve the performance of voltage source converter-high voltage direct current (VSC-HVDC) system, we propose an improved auto-disturbance rejection control (ADRC) method based on least squares support vector machines (LSSVM) in the rectifier side. Firstly, we deduce the high frequency transient mathematical model of VSC-HVDC system. Then we investigate the ADRC and LSSVM principles...

Digital intercept receivers are currently moving away from Fourier-based analysis and towards classical time-frequency analysis techniques, such as the Wigner-Ville distribution, ChoiWilliams distribution, spectrogram, and scalogram, for the purpose of analyzing low probability of intercept radar signals (e.g. triangular modulated frequency modulated continuous wave and frequency shift keying)....

An optimised time-frequency signal analysis software tool is presented here as a MATLAB toolbox. This toolbox is implemented using existing and novel methods for a specific class of Time-Frequency Distributions (TFDs) called quadratic TFDs. This is first applied to a TFD called the Wigner-Ville Distribution (WVD), as all other quadratic TFDs can be represented as a smoothed (in both time and fr...

This paper presents a new approach based on spatial time–frequency averaging for separating signals received by a uniform linear antenna array. In this approach, spatial averaging of the time–frequency distributions (TFDs) of the sensor data is performed at multiple time–frequency points. This averaging restores the diagonal structure of the source TFD matrix necessary for source separation. Wi...