From Wideband to Ultrawideband: Channel Diversity in Low-Mobility Indoor Environments

Dynamic changes in the propagation environment affect transmissions from/to static wireless communication devices. In indoor situations, people moving near transmitting/receiving antennas may alter the propagation channel. To characterize these changing conditions, low-mobility time-domain measurements were taken in three office environments, covering the band from 3.5 GHz to 10.5 GHz. In this paper, we analyze three propagation aspects for bands with different center frequencies and bandwidths ranging from 50 MHz to 5.7 GHz, as follows: the channel diversity (rank); static-to-dynamic changes in received power; and the number of resolvable multipath components. Initial analysis shows that the t location-scale distribution gives the best fit for the dynamic RMS delay spread. Further investigations indicate that channel diversity changes significantly with the environment. Such diversity also depends linearly on the channel perturbation and centre frequency, but its increment due to bandwidth expansion is relatively small.