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

8-20
Propagation Effects for Vehicular and Personal Mobile Satellite Systems
where dS is the change in the received co-polarized power over the 1 MHz frequency
interval df. A regression expression has been established relating the standard deviation
of the fade slope to the mean signal level μSL over the frequency span for each of the
buildings at both L- and S-Band. This expression is given by given by
2
σ FS = a + bμSL
+ cμSL
, (8-7)
where a, b, c are tabulated in Table 8-12 for the L- and S-Band wavelengths. Summary
statistics describing the mean and standard deviation of the fade slopes at the various site
locations are given in Figure 8-12. It is noted from Figure 8-12 that the median fade
slopes (upper figure) varies between 0.5 and 1.3 dB/MHz and the corresponding median
standard deviations (lower figure) vary between 1.8 and 0.7 dB/MHz. We conclude from
these levels that for a resolution of 1 MHz the frequency distortion is expected to be
small over the frequency range 1680 to 2430 MHz.
Table 8-12: Tabulation of standard deviation parameters in (8-7) for different site
locations at L- and S-Band.
Location
L-Band S-Band
a b c a b c
Commons -0.589 -0.11 0.000 -0.52 -0.123 -0.001
EERL 0.323 0.038 0.004 0.296 0.027 0.003
Farm 0.298 -0.047 0.003 0.196 -0.014 0.003
House 0.169 -0.015 0.002 0.237 0.026 0.004
Motel 0.531 0.063 0.004 0.342 0.047 0.004
Store 0.379 0.008 0.004 0.549 0.057 0.004