A time-frequency distribution for analysis of signals with transient components and its application to vibration analysis

Bilinear time-frequency distributions, which provide simultaneous high reso lution in both time and frequency domains, offer advantages for the analysi s of vibration signals where the harmonic components and sidebands may be c losely spaced. However, the Choi-Williams exponential distribution is found to be unsuitable and aliasing produced by distributions of the Cohen class also causes problems. An alias-free exponential time-frequency distributio n is introduced which combines features of distributions of the Cohen class and the generalized Wigner distribution. The aav distribution is shown to be well suited to the analyses of signals with transient components.