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无线通信基础双语教学课件.ppt


Okumura Model Okumura-Hata Path Loss Model COST 231 Model Lee’s Path Loss Model
Empirical formulation to match Okumura model
Suitable for large cell
ro = 1mil = 1,6 km
Pr
r
Po
k
n
Pr

Po.

d do

.
f fc

.o
Pr

Po
10k
log
d do
10n log
PL,urban (d )dB 46.3 33.9 log10( fc ) 13.82 log10(ht ) a(hr ) (44.9 6.55 log10(ht )) log10(d ) CM
Where a(hr) is the same correction factor as before and CM is 0 dB for medium sized cities and suburbs and 3dB for metropolitan areas.
The path loss is represented as a function of
The carrier frequency, [150, 1500]MHz Antenna heights of base station and mobile
station, hb[30, 200]m, hm[1, 10]m The distance between the base station and
station, hb[30, 200]m, hm[1, 10]m The distance between the base station and
mobile station, [1, 20]Km
Lee’s model can be used to predict area-to-area path loss. The model consists of two parts:
The COST 231 model is restricted to the following range of parameters:
The carrier frequency, [1.5, 2]GHz Antenna heights of base station and mobile
where
A 69.55 26.16 log( fc ) 13.82 log(hb ) a(hm ) B 44.9 6.55log(hb )
C 5.4 2log( fc 28)2 D 40.94 4.78log( fc )2 18.33log( fc )
Lp (d ) Lp (d ) dB

Lp
(d0
)
10
log

d d0


dB ,
d

d0
Without shadowing With shadowing
PL(d )dB L( fc , d ) Aμ ( fc , d ) G(ht ) G(hr ) GAREA
mobile station, [1, 20]Km
The path loss in dB is given by
Lp
dቤተ መጻሕፍቲ ባይዱ



A B log10d A B log10d
C

A

B
log10
d


D
for urban area for suburban area for open area
For a large city
ahm 38.2.2[l9o[glo1g011011.7.554hhmm]]2241..917
for fc 200MHz for fc 400MHz
fc=900MHz hb=50m hm=3m
The Hata model was extended by the European cooperative for scientific and technical research (EURO-COST) to 2GHz
a(hm) is the correction factor for mobile antenna height, and is given by
For a small and medium city
ahm [1.1log10 fc 0.7]hm [1.56log10 fc 0.8]
The power at a 1.6km (1 mile) of interception P0 in dBm The path-loss exponent k.
The specified set of conditions is as follows:
Carry frequency fc = 900MHz Base station antenna height = 30.48 m(100 ft) Base station power at the antenna = 10 W Base station antenna gain = 6 dB above dipole gain Mobile station antenna height = 3 m (10 ft) Mobile station antenna gain = 0 dB above dipole gain
Path loss prediction for a specified set of conditions Adjustment factors for a set of conditions different from the specified one
The model requires two parameters:
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