LTE PRACH Measurement
R&S
®
CMW-KM5xx/-KS5xx
769
User Manual 1173.9628.02 ─ 16
Fig. 4-18: Trigger settings
Trigger Source
Selects the source of the trigger event. Some of the trigger sources require additional
options.
●
IF Power:
The measurement is triggered by the power of the received signal, converted into
an IF signal. The trigger event coincides with the rising or falling edge of the detec-
ted LTE burst (i.e. the start or end of the preamble for a PRACH UL signal). Param-
eter
is also relevant.
●
…External…:
External trigger signal fed in via TRIG A or TRIG B on the rear panel of the instru-
ment.
Remote command:
Trigger Slope
Qualifies whether the trigger event is generated at the rising or at the falling edge of
the trigger pulse. This setting has no influence on the evaluation of trigger pulses provi-
ded by other firmware applications.
Remote command:
Trigger Threshold
Defines the input signal power where the trigger condition is satisfied and a trigger
event is generated. The trigger threshold is valid for power trigger sources. It is a dB
value, relative to the reference level minus the external attenuation (<Ref. Level>
–
<External Attenuation (Input)>
–
<Frequency Dependent External Attenuation>). If the
reference level is set to the actual maximum output power of the DUT, and the external
attenuation settings are in accordance with the test setup, then the trigger threshold is
referenced to the actual maximum RF input power at the R&S
CMW.
A low threshold may be required to ensure that the R&S
CMW can always detect the
input signal. A higher threshold can prevent unintended trigger events.
Remote command:
Trigger Timeout
Sets a time after which an initiated measurement must have received a trigger event. If
no trigger event is received, a trigger timeout is indicated in manual operation mode. In
remote control mode the measurement is automatically stopped.
GUI Reference
深圳德标仪器
135-1095-0799
