570
Chapter 16
W-CDMA Uplink Digital Modulation for Receiver Test
W-CDMA Uplink Concepts
The signal generator’s behavior, when
Out Sync
is displayed, depends on the trigger mode used.
describes the signal generator’s behavior for different trigger modes.
Special Power Control Considerations When Using DPCCH/DPDCH in Compressed Mode
or PRACH
When using either DPCCH/DPDCH in compressed mode or PRACH, more than a single power level is
required. In addition to the rapidly varying power levels for these two channels, there are also periods of
discontinuous transmission (gaps where no RF is transmitted). Under these conditions, the automatic level
control (ALC) will try to counteract the rapid power variations. To prevent this, the signal generator employs
ALC hold mode. However, even with ALC hold active, if the RF gap is longer than five seconds, the output
level may drift significantly. Under certain conditions, such as waiting for an input trigger, the length of the
RF gap is unpredictable. Under these conditions, the signal generator turns the ALC off.
shows the specific settings of the DPCCH/DPDCH in compressed mode or PRACH that will turn
the ALC off. Notice that the settings may differ for the mechanical attenuator.
Table 16-9
Trigger Mode
ESG output signal status on
Out Sync
.
Single
The ESG outputs frames even if
Out Sync
is displayed.
Continuous
The ESG output is discontinued. The synchronization is corrupt and no output is
available when
Out Sync
is displayed. The ESG timing is retriggered by the
external trigger when this occurs.
Table 16-10
Conditions that Turn the ALC Off
Channel Type
Electronic Attenuator
Mechanical Attenuator
(Option UNB)
PRACH Settings
PRACH Trigger Source Immedi
Trigger
softkey set to Trigger
Message Part
data field set
to AICH
or
PRACH Mode Single Multi
softkey is set to Multi
PRACH Trigger Source Immedi
Trigger
softkey set to Trigger
or
Message Part
data field set
to AICH
or
PRACH Mode Single Multi
softkey is set to Multi
DPCCH/DPDCH Settings
not applicable
all compressed frames
(no normal frames)
Содержание E4428C
Страница 22: ...Contents xxii ...
Страница 107: ...Chapter 3 83 Basic Operation Using Security Functions Figure 3 6 ESG Screen with Secure Display Activated ...
Страница 182: ...158 Chapter 4 Basic Digital Operation Using Waveform Clipping Figure 4 22 Rectangular Clipping ...
Страница 183: ...Chapter 4 159 Basic Digital Operation Using Waveform Clipping Figure 4 23 Reduction of Peak to Average Power ...
Страница 224: ...200 Chapter 4 Basic Digital Operation Creating and Using Bit Files ...
Страница 228: ...204 Chapter 5 AWGN Waveform Generator Configuring the AWGN Generator ...
Страница 229: ...205 6 Analog Modulation ...
Страница 276: ...252 Chapter 7 Digital Signal Interface Module Operating the N5102A Module in Input Mode ...
Страница 286: ...262 Chapter 8 Bluetooth Signals Turning On a Bluetooth Signal ...
Страница 287: ...263 9 BERT This feature is available only in E4438C ESG Vector Signal Generators with Option 001 601or 002 602 ...
Страница 330: ...306 Chapter 9 BERT Verifying BERT Operation ...
Страница 366: ...342 Chapter 10 CDMA Digital Modulation IS 95A Modulation ...
Страница 394: ...370 Chapter 12 Multitone Waveform Generator Applying Changes to an Active Multitone Signal ...
Страница 454: ...430 Chapter 15 W CDMA Digital Modulation for Component Test W CDMA Concepts Figure 15 9 Uplink Channel Structure ...
Страница 468: ...444 Chapter 15 W CDMA Digital Modulation for Component Test W CDMA Frame Structures ...
Страница 667: ...643 18 Troubleshooting ...
Страница 700: ...Index 676 Index ...