LTE Multi Evaluation Measurement
R&S
®
CMW-KM5xx/-KS5xx
494
User Manual 1173.9628.02 ─ 16
3.2.1.2
How to Measure an Uplink LTE Signal
After connecting your LTE UE to the R&S
CMW, you have to adjust at least the follow-
ing analyzer settings to the properties of the analyzed UL LTE signal:
●
"Duplex Mode"
●
Analyzer "Frequency"
●
"Expected Nominal Power", "External Attenuation (Input)" and "User Margin"
Recommended values: "Expected Nominal Power" = peak power of the UE signal
during the measurement; "User Margin" = 0 dB. The smallest possible value of the
"Expected Nominal Power" plus the "User Margin" ensures maximum dynamic
range.
For synchronization to the received signal and proper decoding, a number of settings
must be in accordance with the measured signal. In particular, ensure that the follow-
ing parameters match up:
●
For TDD signals: "Uplink Downlink", "Special Subframe" and "Measure Subframe"
Ensure that you select an UL subframe as "Measure Subframe". When a frame
trigger signal is used, subframe 0 selected by default is a DL subframe.
●
Length of the "Cyclic Prefix"
●
"Channel Bandwidth"
●
For signals with PUCCH: "PUCCH Format"
●
"Physical Cell ID" and "Delta Seq. Shift PUSCH"
●
"Group Hopping"
The R&S
CMW can auto-detect the "Modulation Scheme" of the received signal.
With matching "Measurement Control" settings, the R&S
CMW is able to decode the
signal and determine its frame timing. No additional measurement trigger is required
(see
chapter 3.2.1.6, "Trigger Modes"
Non-matching "Measurement Control" settings generally result in large EVM results.
3.2.1.3
Defining the Scope of the Measurement
The LTE "Multi Evaluation" measurement can capture up to 320 consecutive sub-
frames, starting at a configurable offset from the trigger event.
The results "Power Monitor" and "RB allocation table" are available for the entire range
of captured subframes. All other TX measurement results are derived from a selected
subframe within the range of captured subframes.
For TDD signals, you must ensure that the selected subframe (measure subframe) is
an uplink subframe. Which subframe is labeled 0, depends on the type of trigger signal
and the subframe offset. For subframe offset 0, the subframe labeled 0 is an uplink
subframe for power trigger signals (first detected uplink subframe) and a downlink sub-
frame for frame trigger signals (first subframe of frame).
For signals with carrier aggregation, some results are available for PCC and SCC.
Other results are measured either on the PCC or on the SCC, depending on the
selected "Measurement Carrier". For details, see
chapter 3.2.1.4, "Carrier Aggrega-
General Description
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