Rohde & Schwarz R&S CMW-KM300, Руководство пользователя, Страница: 348 / 388

NB-IoT NPRACH Measurement
R&S
®
CMW-KM300/-KS300
348 User Manual 1178.5689.02 ─ 06
Trigger
event
Trigger
armed
t
Minimum
Trigger
Gap Min.
Trigger
Gap
No trigger
event Trigger
event
Trigger armed
Min.
Trigger
Gap
Start of
measure-
ment
Minimum
Trigger
Gap
No trigger
event
Min.
Trigger
Gap
This parameter can be used to prevent unwanted trigger events due to fast power var-
iations within a preamble.
The minimum trigger gap must be large enough to ensure that the measurement is not
retriggered within a preamble. It must be small enough to ensure that the trigger sys-
tem is rearmed before the next preamble starts. The default value is often appropriate.
Remote command:
TRIGger:NIOT:MEAS<i>:PRACh:MGAP
4.3.6 Limit Settings
The following sections give an overview of the NPRACH measurement limit settings
and the related conformance test requirements.
Conformance requirements for NB-IoT transmitter tests are specified in 3GPP TS
36.521, section 6, "Transmitter Characteristics".
● Transmit Modulation Limits ................................................................................... 348
● Power Dynamics Limits .........................................................................................349
4.3.6.1 Transmit Modulation Limits
Access: "NPRACH" tab > "Config" hotkey > "Limits" > "Modulation" section.
A poor modulation accuracy of the UE transmitter increases the transmission errors in
the uplink channel of the network and decreases the system capacity. The error vector
magnitude (EVM) is the critical quantity to assess the modulation accuracy of a UE.
According to 3GPP, the EVM measured at UE output powers ≥ −40 dBm must not
exceed 17.5 %.
Characteristics Refer to 3GPP TS 36.521 V14.2.0, section... Specified limit
EVM (RMS) 6.5.2.1F.1 Error Vector Magnitude (EVM) for category NB1 ≤ 17.5 %
Modulation limit settings
The EVM limits can be set in the configuration dialog, along with limits for the other
measured quantities.
GUI Reference
深圳德标仪器
135-1095-0799