Impact of mobile acceleration on the statistics of rayleigh fading channel

Clarke's model of the received signal statistics in a mobile isotropic scattering environment assumes a constant mobile velocity, a consequence of which is that the autocorrelation function of the received signal and the Power Spectral Density (PSD) are independent of the absolute time. In this contribution we relax the assumption of constant mobile velocity and analyze the statistics of the channel when the mobile receiver has a constant acceleration. First, we derive expressions for a general scattering environment and, then, specialize them to the case of isotropic scattering environment. The autocorrelation and PSD of the channel are not only a function of the lag,, but the absolute time index, n as well. There are now two kinds of PSDs: The conventional PSD, based on the well-known Wiener-Khintchine theorem, gives the spectrum in the domain. The second PSD is concerned with the variation of the channel with time and gives the spectrum in the n domain. The simulation results suggest that the two PSDs show a pattern of periodicity which can be explained by considering asymptotic approximation of the Bessel function. Moreover, the magnitudes of the PSDs diminish with increasing or n such that the conventional PSD approaches uniform distribution over 0 to 2π when time n is large whereas the PSD of channel variation with time approaches zero for large We give results on the basis of simulations and justify analytically, or heuristically. We also discuss different implications of these results.