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

8-12
Propagation Effects for Vehicular and Personal Mobile Satellite Systems
Table 8-6: Parameter values for standard deviation versus bandwidth as given by (8-4)
and (8-5).
Site
1 1.6 0.12 0.61
2 1.6 0.03 0.56
3 2.6 2.82 -0.31
4 1.7 0.42 0.42
5 1.4 -0.02 0.55
6 2.4 1.9 0.31
8.3 Slant-Path Building Penetration Measurements at L- and S-Band
In this section, we describe the results of another campaign of Vogel et al. [1995a, 1995b]
who executed L- and S-Band slant path fade measurements in six different buildings
employing a tower-mounted transmitter and a dual frequency receiver system. Separate
circularly polarized antennas were used at the receiving end of the link. The objective of
this set of measurements was to provide inside building signal loss information associated
with personal communications satellite design. In particular, the correlation of fading
inside buildings between frequencies near 1620 MHz and 2500 MHz was examined. The
measurements described in the previous section [Vogel and Torrence, 1993] were
targeted towards the application of broadcasting from geostationary satellites as they used
a relatively directive receiving antenna in their measurements. In the effort described
here, azimuthally omni-directional antennas were employed which interact to a greater
degree with the multipath environment.
8.3.1 Experimental Description
The measurement system is comprised of a single transmitting antenna located
approximately 20 m from the ground atop a tower mounted on a van. Transmissions
were executed in one of two modes. Mode 1 corresponded to the case in which
transmission occurred at simultaneous fixed frequencies of 1618 and 2492 MHz. Mode 2
corresponded to the case in which simultaneous radiation occurred at two swept
frequency ranges, namely, 1580-1780 MHz and 2330-2530 MHz. The L- and S-Band
receiving antennas were spaced 5 cm apart and both were mounted on a positioner
(described in the previous section) capable of automatically scanning either in the vertical
or horizontal at 5 cm increments over a range of 80 cm (16 positions). As mentioned, the
receiving antennas had patterns that were azimuthally omni-directional with a peak gain
at about 30° in elevation. When Mode 1 was selected, the processed outputs were
relative power level versus time for L- and S-Band with a time sampling rate of 100 Hz.
When Mode 2 was selected, processing resulted in frequency spectra over ±80 MHz
relative to the center frequencies of 1680 and 2430 MHz with about 1 MHz resolution
and obtained over a 0.1 s sweep duration. In this mode, 160 sample pairs for L- and
S-Band were saved to a computer file for every sweep lasting 0.1 s. Subsequent to the