User`s guide

294 Chapter 13
W-CDMA Digital Modulation for Component Test
W-CDMA Downlink Modulation
W-C DM A Downl ink Modul ation
This section teaches you how to build W-CDMA downlink waveforms for testing component
designs. The waveforms are generated by the signal generator’s internal dual arbitrary
waveform generator.
Activating a Predefined W-CDMA Downlink State
This procedure teaches you how to perform the following tasks:
• “Selecting a Predefined W-CDMA Setup” on page 294
• “Generating the Waveform” on page 294
• “Configuring the RF Output” on page 294
Selecting a Predefined W-CDMA Setup
1. Press
Preset.
2. Press
Mode > W-CDMA > Arb W-CDMA.
3. Press
W-CDMA Select > 3 DPCH.
This selects three predefined dedicated physical channels (DPCH) for a downlink waveform.
The display changes to DL WCDMA Setup: 3 DPCH. Downlink is the signal generator’s default
setting for link direction and, therefore, does not need to be set.
Generating the Waveform
Press
W-CDMA Off On until On is highlighted.
This generates the predefined 3 DPCH W-CDMA downlink waveform. During waveform
generation, the WCDMA and I/Q annunciators appear and the waveform is stored in volatile
ARB memory. The waveform is now modulating the RF carrier.
Configuring the RF Output
1. Set the RF output frequency to 2.17 GHz.
2. Set the output amplitude to
−10 dBm.
3. Press
RF On/Off until On is highlighted.
The predefined W-CDMA downlink signal is now available at the signal generator’s RF
OUTPUT connector.