Technical data

Chapter 19 539
W-CDMA or W-CDMA (with HSDPA) Analyzer
Using the W-CDMA or W-CDMA (with HSDPA) Analyzer
W-CDMA or W-CDMA (with HSDPA)
Analyzer
+20 dBm (100 mW). When using the 8481A/8482A or N8481A/N8482A with
Option CFT Power Sensors, the maximum input power applied to the Power Sensor
is +24 dBm (300 mW). When using the 8481D Power Sensor, the maximum input
power is +20 dBm (100 mW). When directly coupled to a base station (BTS) or
Access Network (AN), the test set can be damaged by excessive power applied to
any of these three ports.
To prevent damage in most situations when you directly couple the test set to a base
station, use the high power attenuator between the test set and the BTS.
NOTE Most base stations also provide a coupled output, which is a port used for testing.
This output port is usually in the form of a small RF connector on the front of the
base station rack, located on or near the high power amplifier module, and is usually
labeled “Test Out,” “Monitor Out,” or “Tx MON” or “TEST.” Be sure to check the
specifications provided by the base station's manufacturer prior to connecting the
E7495A/B test set. This enables you to determine the output power range of this test
port, and therefore avoid the possibility of damaging the test set.
Preparing to Make W-CDMA or W-CDMA (with HSDPA) Tx
Analyzer Measurements
The first step in measuring W-CDMA transmitter performance (with or without
HSDPA) is to take the base station out of service. In-service measurements are also
possible, as long as you either use an external coupler, or you use a test port as
described in the note above. The next step is to choose the type of time reference
available. The measurement configuration depends upon the type of time reference
you choose. If you use GPS as your time reference, you can also use it to verify the
frequency independently.
You must know the channel or carrier frequency of the transmitter to be analyzed.
Additionally, each base station sector has a unique scrambling code that is
transmitted to mobiles in that sector. These scrambling codes can be detected
automatically by the test set, or can be entered manually if desired.