Experimental Analysis of the Multipath Lifetime in Indoor Millimeter-Wave Channels

Dense spatial sampling of a radio channel where measurements are carried out in many spatial locations is often necessary to accurately capture the multipath components (MPCs) lifetime, i.e., the birth and death process of the MPCs. However, dense spatial sampling is limited by a channel sounder's capabilities, such as the number of channel impulse responses (CIRs) per unit time that can be recorded and the measurement duration required to capture the CIRs. The number of spatial samples can be reduced significantly by an interpolation of the channel in a given interval in postprocessing. However, interpolation of the channel requires that there is no significant birth and death of the dominant MPCs in the selected interpolation interval. In this letter, a configuration of two antenna arrays is proposed for monitoring the birth and death of MPCs by comparing the frequency correlation signature of the arrays thus enabling a reduction of the density of spatial sampling. This is validated in an indoor scenario at the millimeter-wave frequency band from 26.5 to 30 GHz along a linear trajectory.