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6-35
D-620003-0-20 Rev J
CONFIDENTIAL
Link Budget Analysis
• e: enter the noise figure and gain of each system component (a, b, c, and d) into
the standard cascaded noise figure formula
• h = e + f + g
• m = h + i + j –k – l
• r = n + o + p + q
• t = s – r – m
6.4.5
Considerations for Re-Radiation (Over-the-Air) Systems
Unison can be used to extend the coverage of the outdoor network by connecting to a
roof-top donor antenna pointed toward an outdoor base station. Additional consider-
ations for such an application of Unison are:
• Sizing the gain and output power requirements for a bi-directional amplifier
(repeater).
• Ensuring that noise radiated on the uplink from the in-building system does not
cause the outdoor base station to become desensitized to wireless handsets in the
outdoor network.
• Filtering out signals that lie in adjacent frequency bands. For instance, if you are
providing coverage for Cellular B-band operation it may be necessary to filter out
the A, A’ and A” bands which may contain strong signals from other outdoor base
stations.
Further information on these issues can be found in LGC Wireless’ application notes
for re-radiation applications.
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)
