Small-scale delay-domain statistics of the frequency-selective indoor wireless channel

In this paper, electromagnetic signal propagation in the frequency-selective indoor wireless channel is investigated with the help of ultra-wideband channel measurements. Delay-domain statistics used to characterise the multipath delay spread are evaluated numerically. The spatial variation of these parameters over a short range is studied, and their statistical behaviour is analysed. It is demonstrated that the mean and rms delay spread exhibit spatially distributed alternating zones of high and low spread over a short range corresponding to electromagnetic interference fringes. Furthermore, they are approximated with Gaussian random variables. A theoretical explanation is provided for this small-scale behaviour.