NB-IoT Multi-Evaluation Measurement
R&S
®
CMW-KM300/-KS300
241
User Manual 1178.5689.02 ─ 06
3.3.6.4
Inband Emissions Limits
Access: "Config" hotkey > "Limits" > "Modulation" > "IBE" section.
The inband emission is the relative UE output power in non-allocated subcarriers
(SCs). Inband emissions are interferers in the subcarrier range that is potentially used
by other connected UEs. 3GPP defines a complex combined inband emission limit
described below.
The combined limit can be determined via the following rules:
●
The minimum of the combined limit is -30 dB. In the R&S
CMW, this general mini-
mum is configurable.
●
A general component is considered for all non-allocated SCs.
●
For non-allocated SCs at image frequencies of allocated SCs, an IQ image compo-
nent is added to the general component.
●
For SCs at the carrier frequency or next to the carrier frequency, an IQ offset com-
ponent is added to the general component.
So the most complex limit must be determined for a non-allocated SC located both at
an image frequency and next to the carrier frequency. In that case, the general compo-
nent, the IQ image component and the IQ offset component have to be added. Then
the result must be compared to the general minimum and the bigger value of both
applies.
The following table provides an overview of the three components.
Component
Value
Applicable SCs
General
See formula below table
Non-allocated SCs
IQ image
-24.2 dB
Image frequencies
IQ offset
-24.2 dBc to -9.2 dBc, depending on TX power
Chapter 3.3.6.3, "I/Q Origin Offset Limits"
Carrier frequency
The general limit is derived using the following formula:
dB
0.8
dB
Meas
Power
SC
Power
SC
,
SC
No
1)
Offset
(
5
18
,
SC
No
SC
All
log
10
15
max
Limit
10
General
The variables are defined as follows:
●
<All SC> = total number of subcarriers within the channel bandwidth
●
<No SC> = number of allocated subcarriers
●
<Offset> = distance of the SC from the closest allocated SC
●
<SC Power> = -57 (configurable)
GUI Reference
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