Chapter 3 WCDMA Non-Call Mode
RF Analyzer for spectrum
WCDMA Options Version 6.20
95
RF Analyzer for spectrum
The group of spectrum measurements available in the Spectrum menu offers
functions for measuring the RF output spectrum emission. These functions are
used to measure the parameters for assessing the quantity of power that leaks
outside the assigned radio channel, i.e. the off-carrier power. If this power value
exceeds certain limits, interference with neighbouring channels may increase.
Furthermore, system capacity may be affected. Spectrum measurements for
WCDMA include Occupied Bandwidth (OBW), Adjacent Channel Leakage Power
Ratio (ACLR) and Spectrum Emission Mask (SEM).
To gain access to this menu, select the [Spectrum ... ] marker tab while working
in Generator/Analyzer mode.
In the Spectrum menu three marker tabs for the different spectrum analyzer
measurements are available: OBW, ACLR and SEM. On selecting
[Spectrum ... ] from the RF Gen., Power or Staircase menu the OBW marker tab
will be selected by default.
OBW (Occupied
Bandwidth)
This measurement shows the bandwidth which the UE’s signal occupies. The
occupied bandwidth identifies the frequency range into which a given
percentage of the signal power falls. 99% of the entire power should be spread
within a range of no more than 5 MHz around the carrier frequency. The purpose
of this measurement is to verify that the UE’s occupied bandwidth is lower than
5 MHz based on a chip rate of 3.84 Mcps. An occupied bandwidth exceeding this
value may increase interference with other channels or other systems
.
Parameters Max Level — Selection field for the level at which the measurement is to be
performed. The field’s drop-down list offers a value range from –20 dBm to
30 dBm.
Res BW — Selection field for the resolution bandwidth, i.e. the filter resolution,
to be used for measuring. In the field’s drop-down list you can choose between
15 and 30 kHz.
Span — Selection field for the span to be used for measuring. In the field’s drop-
down list you can choose between ±3 and ±5 MHz.
Avg — Push the softkey
Start Avg. and use the arrow keys to go to the Avg field
to define the number of last measurements results over which to average. The
default value is 1, you can increase the value using the upward arrow key.
Count — Counter field displaying the number of measurements being taken.
For a description of the frequency and channel parameter entry fields see “RF
Analyzer parameter fields” on page 103.
To Next Page
Loading...
