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

11-8
Propagation Effects for Vehicular and Personal Mobile Satellite Systems
ENV = -1 (Suburban/Rural)
HEAD = +1 (AzVehicle - AzSatellite = 90°)
FREQ = 1.8 (L-Band)
SIDE = -1 (Satellite Same Side)
ELEV = 45°.
Substituting the above into (11-10) and (11-11), we obtain
(11-17)
μ = 9.
5 dB , (11-18)
σ = 4.
33 dB . (11-19)
Substituting (11-18), (11-19) and k = 1.65 (from (11-12) for PL = 95%) into (11-9) results
in
A = 16.5 dB for PS = 90% (11-20)
The fade given by (11-20) corresponds to a large-scale probability of PL = 95% and
small-scale probability of PS = 90%. To convert the above to the desired small-scale
probability PS = 70 %, substitute (11-20) into (11-16). Hence
A = 14.5 dB for PS = 70%. (11-21)
In Figure 11-1 is given a family of curves of the large-scale cumulative distributions PL
for elevation angles of 20°, 30°, and 45° with small-scale probabilities of PS = 90%, 70%,
and 50%. This figure corresponds to an overall driving condition as each curve
represents the average of four distributions; right side of road, left side of road and
difference in vehicle-satellite azimuth directions of 90° and 0°. We note that PL is
relatively insensitive to elevation angle but is highly sensitive to PS.