In-band Emissions (NB-IoT)

In-band Emissions shows the resource subcarrier spectrum for the data specified by Measurement Interval and Measurement Offset.

The In-band Emissions trace has the following characteristics:

In-band Emissions always includes Non-alloc signals, regardless of the Non-alloc parameter selection.
In-band Emissions includes autogenerated limit test for each slot. To keep the trace uncluttered, limit line is drawn only for the slot with the worst emissions.
RB Power levels are normalized such that the average active RB power is 0 dB.
Any IQ Offset (carrier leakage) present in the signal is not compensated.

Resource block points whose power exceeds the limit are drawn in red.

The marker readout shows the result of the In-band Emissions limit test as either PASS or FAIL. The marker readout also shows the location of the resource block that has passed with the tightest margin or failed with the widest margin.

The In-band Emissions trace is not available in uplink when analyzing NPUSCH and the number of tones is set to 12.

Although the limits for this trace are auto-generated, the limits can be customized by performing the following steps:

Select the In-band Emissions trace by clicking the trace title.
Click Utilities > Limit Tests > From Trace

This will open the Limit Test Editor dialog with limits extracted from the In-band Emissions trace.
Modify the limit test
1. Select the Upper limit and click Edit.
2. Click the Points tab and modify the limit line points.
3. Type a name for the limit line in the Name field and click OK to save the limit line.
4. Type a name for the limit test in the Name field and click OK to save the limit test.
Apply the modified limit test
1. Click Markers > Limits…
2. Select the modified limit test.

The selected limit test will continue to be applied in all subsequent measurement sweeps.

To revert to auto-generated limit lines, select the In-band Emissions trace, click Markers > Limits…, and select <Limit Test from Trace>.

For more information about limit lines, see the About Limit Lines topic.