Time-Frequency Signal Analysis And Synthesis The Choice Of A Method And Its Application

Abstract

In this paper, the problem of choosing a method for time -frequency signal analysis is discussed.

Application Of The Wigner-Ville Distribution To The Identification Of Machine Noise

“…Since the signal contribution is concentrated around fi(t) [1], the application of a 2D windowing which preserves all the points (t,f) in the neighbourhood of fi(t) and filters out the others, preserves the useful information in the signal and indeed increases by an order of magnitude the SNR.…”

“…Following their approach the results are extended for application to the WVD, which uses the analytic signal, and therefore provides fundamental and practical advantages over the WD which uses the real signal [ 1 ].…”

“…The WVD of a signal s(t) is defined as Wz (t,f) = / zs (t+r/2) zs *(t-T/2)e~3 27TfTdx (1) where zs (t) is the analytic signal corresponding to s(t). (All integrals are from -co to +<»).…”

<title>Time-frequency distributions for propulsion-system diagnostics</title>

“…Two properties [3] most relevant to us are: one, the first moments of the WVD yield the instantaneous frequency and group delay of the signal, and two, the WVD exhibits a range of peaks along the curve which describes the instantaneous frequency and group delay. (See Cohen {1J for additional properties.…”

“…TFDs have been demonstrated as an effective analysis tool for tracking time-varying signals [3] , [4] , [5] . In some of our previously published work {6} , [7J , [8] , we showed that we can detect time-frequency features in the data which correlated remarkably well with documented failure indications.…”