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

8-8
8.2.5 Frequency Dependence of Probability
Propagation Effects for Vehicular and Personal Mobile Satellite Systems
The dependence of exceedance probability on frequency (f) and relative signal loss (SL)
at frequencies from 750 MHz to 1750 MHz has been found to follow the least square
relation
where
P = α + β × f , (8-1)
α α + α × SL , (8-2)
= 0 1
β β + β × SL , (8-3)
= 0 1
and where α0, α1, β0, β1 are tabulated in Table 8-5 for the various site locations. Also
tabulated in Table 8-5 is the RMS error of P in percent. Example distributions are given
for Site 2 at 750 MHz, 1.25 GHz and 1.75 GHz in Figure 8-4.
Table 8-5: Best fit coefficients for the model cumulative distributions (8-1).
Site α0 α1 β0 β1
RMS Error
in P (%)
1 66.2 5.3 16.0 -0.54 4.0
2 74.1 7.0 20.3 -1.2 8.4
3 105.7 3.1 -7.8 -0.34 2.8
4 97.8 6.2 -3.8 -1.5 3.4
5 67.2 5.2 224.9 -0.1 6.1