A time-filtered Wigner transformation for use in signal analysis

Two important goals of time-frequency transformations in signal analysis are high time and frequency resolution and simple interpretableness. The Wigner transformation exceeds the frequently used spectrogram with respect to the resolutions, it possesses. however. interference terms, which makes the interpretation difficult. In this paper a procedure is presented, with which by repeated filtering in time domain and subsequent Wigner transformation a transformation result is achieved, in which the time-frequency resolution of the Wigner transformation is maintained and at the same time the interference terms can be removed, By a practical example. the advantages of this procedure are clarified in relation to the spectrogram and the original Wigner transformation. (C) 2002 Elsevier Science Ltd. All rights reserved.