User`s guide

396 Chapter 15
W-CDMA Uplink Digital Modulation for Receiver Test
Setting Up a Multiple PRACH Signal
signal output may show different characteristics.
1. Preset the signal analyzer.
2. Select the Spectrum Analysis mode.
Press
Mode > Spectrum Analysis.
3. Set the center frequency.
Press
Frequency Channel > Center Freq > 1.95 > GHz.
4. Select the zero Hertz span.
Press
Span > Zero Span.
This sets the PSA to function like an oscilloscope measuring in time rather than frequency.
5. Set the sweep time to 80 ms.
Press
Sweep > 40 > ms.
6. Set the resolution bandwidth for a quick response time that captures the bursting nature
of the PRACH components.
Press
BW/Avg > 8 > MHz.
Whenever you make a measurement in the zero Hertz span, you need to set the resolution
bandwidth to its maximum value to ensure capturing all of the signal characteristics.
7. Trigger the signal analyzer from the rear trigger input using the ESG trigger signal
selected in the section, “Selecting the Rear Panel Output Trigger” on page 381.
Press
Trig > Ext Rear.
8. Set the PSA to average the signal measurement.
Press
Det/Demod > Detector Auto Norm > Average.
9. Lower the reference level to -10 dBm.
Press
Amplitude Y Scale > Ref Level > 10 > −dBm.
10.Resolve the display for a closer view of the signal.
Press
Scale/Div > 5 > dB.
11.Remove the Scale/Div 5.00 dB text from the display.
Press the
ESC hardkey.