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

9-16
Propagation Effects for Vehicular and Personal Mobile Satellite Systems
Table 9-3: Values of parameters a, b, c for upper lower bounds of –10 dB spectral
bandwidth (9-32).
f-10 a b c
Upper Bound
f-10U
Lower Bound
f-10L
-1140489.7 1140489.4 -2129739.7
9.4.1 Example Calculation
-0.99312632 0.97234278 -16.718273
It is desired to find the mean fade occurrence interval TI (P)
and the mean fade duration
TD (P)
under the following conditions:
and
P = 95% (9-33)
θ = 5°
. (9-34)
o
Step 1: Evaluate α and m(P).
Substitute P given by (9-33) into (9-31) and evaluateα and m(P). We obtain
α = 0 . 699,
m(
P)
= 1.
645 . (9-35)
Step 2: Evaluate the upper and lower bounds of the –10 dB spectral bandwidth f-10.
Substituting coefficients of Table 9-3 into (9-32) for θ o given in (9-34), we obtain
f . 378,
f = 0.
318
(9-36)
−10 U = 2 −10
L
Step 3: Evaluate the mean fade occurrence interval at P=50%.
Substituting (9-36) into (9-30), we obtain
T ( 50%)
= 0.
7285,
T ( 50%)
= 5.
4435 , (9-37)
I
U
I
L
where the subscripts U, L denote the upper and lower bounds of f-10 in (9-36),
respectively.
Step 4: Evaluate T ( 95%)
at the upper and lower bound of f-10.
I
Substituting T ( 50%)
given in (9-37) and m(P) given in (9-35) into (9-28),
I
TI U
I
L
( 95%)
= 2.
8s,
T ( 95%)
= 21.
1s
(9-38)