Comments on "On verifying the first-order Markovian assumption for a Rayleigh fading channel model"

For original paper see Wang and Chang IEEE Trans. Veh. Technol., vol.45, p.353-7 (1996). In the present paper, the trivariate probability density function (PDF) for the envelope of a bandpass Gaussian process is derived. However, the multivariate PDF for the envelope of a bandpass Gaussian process having an arbitrary power spectrum has been previously reported. The Markovian behavior of the envelope process for the U-shaped power spectrum 1//spl radic/(1-f/sup 2/) was studied by Wang and Chang using an information theoretic approach. It is worth mentioning that several authors have formerly discussed that Markovian behavior for the rational power spectrum 1/(1+f/sup 2/) from a probabilistic point of view.