Chapter 14
387
Real Time TDMA Formats
GSM Framed Modulation
Disabling Timeslot Ramping
1. Press
Timeslot #
>
1
>
Enter
.
2. Press
Multislot Off On
to On.
3. Press
Return
.
Turning multislot on disables ramping between the current and the next higher numbered (adjacent)
timeslot. A line underscores the timeslots where ramping is disabled. For this procedure, ramping will not
occur between timeslots one and two. The multislot choice is a setting for each timeslot.
Generating the Baseband Signal
Press
GSM Off On
to On.
This generates a GSM signal with an active access timeslot, an active custom timeslot, and an active normal
timeslot. The signal generator may require several seconds to build the signal. During this time,
Baseband
Reconfiguring
appears on the display. After the reconfiguration is complete, the display reads
GSM On
and the
GSM
,
ENVLP
, and
I/Q
annunciators appear indicating that the signal is modulating the RF carrier.
Configuring the RF Output
1. Set the RF output frequency to 891 MHz.
2. Set the output amplitude to
−
5 dBm.
3. Press
RF On/Off
to On.
The user-defined GSM signal is now available at the signal generator’s RF OUTPUT connector.
To store this real-time I/Q baseband digital modulation state to the instrument state register, see
.
To recall a real-time I/Q baseband digital modulation state, see
“Recalling an Instrument State” on page 72
Adjusting the Power Level Between Timeslots
1. Press
Amplitude
>
More (1 of 2)
>
Alternate Amplitude
>
Alt Amp Delta
>
–15
>
dB
.
2. Press
Mode Setup
>
Configure Timeslots
>
Timeslot #
>
1
>
Enter
.
3. Press
Timeslot Ampl Main Delta
to Delta.
The power level for timeslot one is now 15 dB lower than the other active timeslots. Selecting Main on the
Timeslot Ampl Main Delta
softkey returns the timeslot to its previous power level. The delta amplitude choice
is available for each timeslot, however all timeslots use the same delta value set in the Alternate Amplitude
softkey menu.
Summary of Contents for E4428C
Page 22: ...Contents xxii ...
Page 224: ...200 Chapter 4 Basic Digital Operation Creating and Using Bit Files ...
Page 228: ...204 Chapter 5 AWGN Waveform Generator Configuring the AWGN Generator ...
Page 229: ...205 6 Analog Modulation ...
Page 276: ...252 Chapter 7 Digital Signal Interface Module Operating the N5102A Module in Input Mode ...
Page 286: ...262 Chapter 8 Bluetooth Signals Turning On a Bluetooth Signal ...
Page 330: ...306 Chapter 9 BERT Verifying BERT Operation ...
Page 366: ...342 Chapter 10 CDMA Digital Modulation IS 95A Modulation ...
Page 394: ...370 Chapter 12 Multitone Waveform Generator Applying Changes to an Active Multitone Signal ...
Page 468: ...444 Chapter 15 W CDMA Digital Modulation for Component Test W CDMA Frame Structures ...
Page 667: ...643 18 Troubleshooting ...
Page 700: ...Index 676 Index ...