Application of Wigner-Ville distribution to measurements on transient signals

The authors deal with an application of the Wigner-Ville distribution (WWD) and with usual digital-processing techniques, such as the short-time Fourier transform (STFT), used in dedicated instrumentation for measuring non-stationary signals. A WWD- and STFT-based virtual instrument (VI) to measure instantaneous frequency and amplitude of the fundamental component of transient signals is presented. The applied algorithms include original interpolation techniques for accurately determining the actual instantaneous frequency, and a suitable flat-top window function for measuring the fundamental amplitude without further amplitude interpolation algorithms. The digital system, uses the Lab View software for easily processing the data sequences, simulated or acquired by a suitable board. Many simulations have confirmed that using the proposed low-cost VI gives measurements of good accuracy, also in the presence of noise