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

Summary of Recommendations 12-11
Diversity Gain (dB)
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
50
40
30
3 Best Satellites
Diversity Type
Dashed: Combining
Solid: Hand-off
20 10
Probability (%)
4 Best Satellites
2 Best Satellites
Best Satellite
Figure 12-4: Diversity gains achieved through satellite pointing methods as a function of
the fade exceedance probability. These curves were derived by simulating the Globalstar
constellation of satellites for urban Japan at 1.6 GHz.
12.6.6 Suggestions for Further Work
Where databases exist at UHF and K-Band, diversity gain simulations based on spaced
antennas should be executed and the results compared with those for L-Band described
above. Satellite diversity simulations should be performed for other frequencies and for
tree-lined roads and mountainous regions.
12.7 Investigations from Different Countries (Chapter 7)
A compendium of cumulative fade distributions associated with land-mobile-satellite
scenarios is given for significant experiments throughout the world. Comparisons are
made between measured distributions and those calculated using the EERS model.
12.7.1 Compendium of Measurements
In Table 12-3 are listed entries of fade levels at the 1% and 10% probabilities for 54
measured distributions. The large range in the fades are caused by such factors as
variable density of foliage cutting the earth-satellite path, bearing to the satellite,
5
2
1