R&S CMW-KG4 Series, Руководство пользователя, Страница: 551 / 988

WCDMA Multi Evaluation Measurement
R&S
®
CMW-KG4xx/-KM4xx/-KS4xx
551 User Manual 1173.9657.02 ─ 11
3.2.1.5 Trigger Modes
The WCDMA multi evaluation measurement can be performed in the following trigger
modes (trigger source settings):
●
Free Run (Standard): The measurement starts immediately after it is initiated. The
R&S
CMW decodes the signal to derive its slot timing so that the "Measurement
Length" can start at a slot boundary of the UL WCDMA signal. This procedure is
repeated after each measurement cycle.
●
Free Run (Fast Sync): Similar to "Free Run (Standard)", however, the R&S CMW
assumes that the frame period of the detected signal is close to the nominal 10 ms
WCDMA frame length. The timing is only corrected after each measurement cycle
using a faster algorithm, which results in faster continuous measurements.
If you experience problems with this trigger mode, use Free Run (Standard)
instead.
●
IF Power: With an internal IF power trigger, the measurement is triggered by the
power ramp of the received bursts. This trigger can be used if no continuous
WCDMA signal is available and a short signal burst has to be measured.
●
IF Power (Sync):
Similar to "IF Power", however, the R&S
CMW tries to synchronize to the signal
during a full slot after the trigger event. This setting can be used to measure short
signal bursts where the beginning of the burst does not exactly coincide with a slot
boundary. The start of the measurement takes longer than with "IF Power".
●
External Trigger A/B: External trigger signal fed in via TRIG A or TRIG B on the
rear panel of the instrument.
●
Additional trigger modes: Other firmware applications, e.g. the WCDMA signaling
application (option R&S CMW-KS400) or the WCDMA generator (option R&S
CMW-KG400) may provide additional trigger modes. Refer to the documentation of
the corresponding firmware application for a description of these trigger modes.
For configuration see chapter 3.3.2.4, "Trigger Settings" , on page 599.
3.2.2 WCDMA RX Tests
RX tests can be carried out in parallel to the TX tests. The following sections describe
how to perform RX tests.
3.2.2.1 Test Setup
The downlink RF generator signal of the R&S CMW is fed to the input of the DUT. The
R&S CMW measures the uplink signal. Most conveniently, a bi-directional connection
with a single coax cable is used. The DUT is connected to one of the RF input connec-
tors (RF COM) at the front panel of the R&S
CMW. No additional cabling and no exter-
nal trigger is needed.
The input level ranges of all RF COM connectors are identical.
See also: "RF Connectors" in the R&S CMW user manual, chapter "Getting Started"
General Description
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