Comments on "A high-resolution quadratic time-frequency distribution for multicomponent signals analysis"

For original paper see Barkat and Boashash (IEEE Trans. Signal Processing, vol.49, p.2232-9, 2001). It is shown that the time-frequency distribution (TFD) proposed in the above paper is not well defined in the ordinary sense for power signals, including the single-tone sinusoid, and it needs the introduction of generalized functions and transforms. It is also shown that the proposed TFD does not satisfy the conditions cited by the authors of the paper to justify the claim that it has the instantaneous frequency property.