Link Budget Analysis
6-28
InterReach Unison Installation, Operation, and Reference Manual
CONFIDENTIAL
D-620003-0-20 Rev J
Table 6-26
Narrowband Link Budget Analysis: Uplink
• e: enter the noise figure and gain of each system component (a, b, c, and d) into
the standard cascaded noise figure formula
• i = f + e + g – h
• m = j + k + l
• p = n – m – i
Therefore, the system is downlink limited but the downlink and uplink are almost
balanced, which is a desirable condition.
Line
Uplink
Receiver
a.
BTS noise figure (dB)
4
b.
Attenuation between BTS and Unison (dB)
–10
c.
Unison gain (dB)
0
d.
Unison noise figure (dB) 1-4-32
22
e.
System noise figure (dB)
22.6
f.
Thermal noise (dBm/30 kHz)
–129
g.
Required C/I ratio (dB)
12
h.
Antenna gain (dBi)
3
i.
Receive sensitivity (dBm)
–97.4
Airlink
j.
Multipath fade margin (dB)
6
k.
Log-normal fade margin with 9 dB std. deviation, 95% area coverage,
87% edge coverage
10
l.
Body loss (dB)
3
m.
Airlink losses (not including facility path loss)
19
Transmitter
n.
Mobile transmit power (dBm)
28
p.
Maximum path loss
(dB)
106.4
F
sys
=
F
1
+
+
+ ....
F
2
– 1
G
1
F
3
– 1
G
1
G
2
where
F
= 10
(See Rappaport, Theodore S.
Wireless Communications, Principles, and Practice
. Prentice Hall PTR, 1996.)
(Noise Figure/10)
G
= 10
(Gain/10)
