Handbook of Propagation Effects for Vehicular and ... - Courses

Earth-Satellite Propagation Effects Inside Buildings 8-25
Relative Level (dB)
5
0
-5
-10
-15
-20
-25
-30
-35
-40
-45
0 1 2
Distance (m)
1023 MHz
1463 MHz
2093 MHz
2992 MHz
Figure 8-15: Relative signal level versus position at four frequencies in the House.
8.4.4 Spatial Autocorrelation Characteristics
The autocorrelations were calculated at approximately 900 frequency samples for lags
from 0 m to 3.2 m. Figure 8-16 gives an example of the spatial autocorrelations versus
frequency for the EERL Building at a lag of 50 cm. The overall data do not exhibit a
clear frequency dependence in spite of the fact that the wavelength at 500 MHz is 60 cm
whereas it is only 10 cm at 3 GHz. The median value of the autocorrelations in Figure
8-16 is 0.37. The autocorrelation as a function of distance at 1625 MHz is plotted in
Figure 8-17 for the Commons, EERL, and the Farmhouse. In Table 8-15 are listed the
median decorrelation distances (i.e., distance at which autocorrelation equals 0.37) for
each of the building sites. It is noted that the overall average is 0.71 m.