A comparison of time delay spread and signal level measurements within two dissimilar office buildings

Abstract

A detailed analysis of time delay spread and signal level measurements at 850 MHz was performed within a large office building. The results were compared with studies of a much smaller and dissimilar office building. The results were found to be substantially the same, despite the physical differences of the buildings themselves. This may be due to external geographical features. Overall worst-case root mean square (rms) time delay spreads in the buildings were 250 ns and 218 ns in the larger and smaller building, respectively. However, these values improved to under 100 ns when there was a good direct path between the antennas. Time delay spread was also shown to be independent of relative antenna polarizations of the transmitter and receiver, even on line-of-sight paths. Received signal levels were below -90 dB with reference to the level at 0.3 m separation, in the worst cases.