User`s guide

174 Chapter 6
BERT Testing
Measuring RF Loopback BER with Option 300
E4406A VSA Series Transmitter Tester” and “Configuring GSM Mode on the ESG Vector
Signal Generator” in this chapter, to prepare the test equipment for synchronization.
2. Set up the base station and start sending the TCH signal now. The TCH is only required to
contain a valid midamble.
3. On the ESG, press
Aux Fctn > BERT > BTS BERT GSM Loopback.
4. Press
Sync Source BCH TCH/PDCH to TCH/PDCH.
5. Press
Configure Measurement > Timeslot # > 2 > Enter.
This sets the ESG to expect the TCH in timeslot 2.
6. Press
Return > GSM BERT Off On to On.
NOTE If the following error message is generated:
522 Demodulator Unleveled; Input amplitude underrange
this indicates that the TCH signal is not being received.
7. Press
Synchronize to BCH/TCH/PDCH to begin synchronization to the TCH.
Then you will see Synchronizing to TCH flashing on the display followed by the
Synchronizing to PN message.
Once synchronization is achieved, the Ready TCH Sync Lock message is displayed. Refer
to Figure 6-9.
Figure 6-9