552 Chapter 16
W-CDMA Uplink Digital Modulation for Receiver Test
W-CDMA Uplink Concepts
Settling Time during User Event for DPCH Compressed Mode
Some user events, such as changing the amplitude or frequency, will cause the signal to jump to an
unexpected amplitude for a short period of time before it settles to expected parameters. This transition
period is approximately 200 milliseconds (see Figure 16-72). It is, therefore, important to allow for this time
when you make changes to signal characteristics. If you make changes using remote SCPI commands, insert
wait instructions into the program. The following events can cause this unstable transition time:
• amplitude and frequency changes
• RF switched on and off
• modulation switched on and off
• ALC switched on and off
• saving or recalling states
Figure 16-72 DPCH Compressed Mode Signal after a Change in Amplitude
Connecting the ESG to a W-CDMA Base Station
Figure 16-73 shows the connections and signals necessary for the ESG to simulate user equipment when it is
connected to a base station.