Four-frequency radiowave propagation measurements of the indoorenvironment in a large metropolitan commercial building

摘要

Time delay spread and signal level measurements were made in alarge commercial metropolitan building at 850 MHz, 1.9 GHz, 4.0 GHz, and5.8 GHz. No significant statistical difference in time delay spread wasfound at the four frequencies. The maximum RMS time delay spread at thefour frequencies did not exceed 120 ns. Attenuation was very nearly thesame at the four frequencies, within the limits of the experiment'saccuracy. The variation of the received signal level with distance couldbe characterized by free space propagation together with attenuation perunit distance. This attenuation coefficient was about the same at thefour frequencies. The RMS fractional deviation was found to be a usefulmeasure of the spread of the data