NB-IoT NPRACH Measurement
R&S
®
CMW-KM300/-KS300
330
User Manual 1178.5689.02 ─ 06
Example: Limited sequence of preambles with increasing power
Scenario: A sequence of 10 preambles with increasing power is measured. Main result
of interest is the TX power of the individual preambles (verify correct ramping up of
preamble power by UE).
Used view: "Power vs Preamble"
Settings: statistic count = 1, number of preambles = 10, repetition = single shot
Example: Statistical evaluation for preambles with constant power
Scenario: The EVM is measured for 100 preambles, so that the average and the maxi-
mum value can be evaluated.
Used view: "EVM"
Settings: statistic count = 100, number of preambles = 1, repetition = single shot
4.2.4
Parallel Signaling and Measurement
The NPRACH measurement can be used in parallel to the NB-IoT signaling application
(option R&S CMW-KS300). The signaling application emulates an NB-IoT cell signal
so that the UE tries to attach and sends random access preambles. These preambles
can then be measured using the NPRACH measurement.
To use both applications in parallel, the combined signal path scenario must be activa-
ted (see
"Scenario = Combined Signal Path"
on page 226). Most signal routing and
analyzer settings are then configured by the signaling application. The NPRACH mea-
surement displays the corresponding signaling settings instead of its own settings.
These signaling settings can be configured both in the measurement GUI and in the
GUI of the signaling application.
To configure these settings via remote commands, the commands of the signaling
application must be used. For a mapping table, see
Chapter 4.5.4, "Combined Signal
The most important signaling parameters not relevant for standalone measurements
can nevertheless be configured both in the measurement GUI and in the GUI of the
signaling application. In the measurement GUI, they can be accessed via hotkeys.
Whenever the combined signal path scenario is activated or the controlling application
is changed, the NPRACH trigger signal provided by the controlling signaling application
is selected automatically as trigger source.
4.2.5
Calculation of Modulation Results
Modulation results are based on a comparison between the measured signal and an
ideal reference waveform.
3GPP TS 36.101, annex F defines that the EVM calculation must be based on two dif-
ferent FFT processing windows in the time domain, separated by the "EVM window
General Description
深圳德标仪器