CDMA2000 Measurements
R&S
®
CMW-KG8xx/-KM8xx/-KS8xx
751
User Manual 1173.9511.02 ─ 11
●
Free Run:
The measurement starts immediately after it is initiated. The R&S
CMW decodes
the signal and derives its timing. Every 26.67 ms a "Measurement Interval" is star-
ted.
●
IF Power:
The measurement is triggered by the power of received signal, converted into an IF
signal. The trigger event coincides with the rising or falling edge of the detected
CDMA2000 power step and is used as a narrow band IF power trigger. For the IF
power settings the RF input signal must be ramping (e.g. a CDMA2000 signal with
a FCH frame rate
≠
Full).
The trigger event has to be synchronized to the start of frame. To achieve that it is
necessary to adjust the "Minimum Trigger Gap".
●
IF Auto Sync
The behavior of this trigger is equal to the IF Power trigger. Only the calculation of
the trigger event is different: The R&S
CMW decodes the measured signal at event
time to derive its power control group and frame timing and to start the measure-
ment at a frame start.
●
…External…:
External trigger signal fed in via TRIG A or TRIG B on the rear panel of the instru-
ment.
●
Others
Other firmware applications, e.g. the CDMA2000 signaling application (option R&S
CMW-KS800) or the GPRF generator, may provide additional trigger modes. Refer
to the documentation of the corresponding firmware application for a description of
these trigger modes.
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 "Free Run" measurements and for
evaluation of trigger pulses provided 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:
GUI Reference
135-1095-0799