Chapter 2 WCDMA Call Mode
Testing User Equipment on WCDMA channels
50 WCDMA Options Version 6.20
Other screen elements Read section “Softkeys in idle mode” on page 43 to learn how to view and modify
channels, power level and other call-related parameters.
Section “Status” on page 40 explains the elements of the status area.
The “Statistical test evaluation” on page 42 tells you how to read the Min/Max/
Avg tables.
The functions of the softkeys depend on whether or not a call has been estab-
lished. See sections “Softkeys in idle mode” on page 43 and “Softkeys at call
level” on page 44 for the available softkey functions.
Chan Pwr
[dBm]
Displays the measured channel power in dBm.
Freq. err.
[Hz]
Here, the 4400 displays the results of the statistical evalua-
tion of the frequency error measurements. The result is
given in Hertz. According to WCDMA specifications the UE’s
carrier frequency shall not deviate from the assigned fre-
quency by more than ±0.1 ppm. Thus the value displayed in
this field shall be in the range of ±200 Hz.
EVM RMS
[%]
Shows the RMS value of the Error Vector Magnitude, i.e. the
RMS value of the error vector measured divided by the RMS
value of the reference signal, expressed as a percentage
value. The EVM shows the deviation of the measured signal
vector from an ideal, calculated signal vector. The root
mean squared Error Vector Magnitude is determined as a
measure of modulation accuracy at the decision points, it is
an average of all the decision points (symbols) across a
whole measurement interval.
According to WCDMA specifications the EVM value shall
not exceed 17.5% at an output power of equal to or greater
than –20 dBm and a power step size of 1 dB under normal
operating conditions.
NOTE
Differences between the commanded power level and the currently measured
results could be due to power losses on connectors and RF cables. Those losses
can be compensated using the Coupling Loss menu in the basic parameters
section.
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