Setting up a 5G NR Measurement

This topic provides information on connecting and successfully demodulating a signal using the 5G NR demodulator. A typical measurement includes the following measurement setup process (each step is discussed in the following text).

1. Connect your signal to the VSA
2. Configure measurement setup and input parameters
   1. Set the Center Frequency
   2. Set the Frequency Span
   3. Configure the Input Range
   4. Configure Triggering (when required)
   5. Verify input signal and initial parameter settings
3. Configure the 5G NR demodulator
   1. Select the 5G NR demodulator
4. Set up 5G NR signal parameters
5. Run the measurement (if measurement time is slow, use the New Radio Speedup macro)

5G NR Measurement Setup Procedure

1. Connect your Signal to the VSA

   • Single or multiple channel connection
     

     Connect the antenna signals to the hardware input channels.

     Click Input > Channels and select the number of channels.

   • I+jQ connections

     Connect the I and Q signals to the measurement hardware. To configure the VSA, choose one of the I+jQ selections: Input > Channels > I + jQ.

     Notes for I+jQ input:

     • Selecting an I+jQ configuration enables DC coupling.
     • Use User Correction to correct for any offset or gain imbalance between the I and Q signals.
     • Range is set independently for the I and Q inputs, but can be coupled by selecting the Couple Paired Channels parameter.

   • Recorded signal

     Recall the recorded signal by selecting File > Recall > Recall Recording

     The center frequency and input range will be set by the recording.

     Information about the sample 5G NR signal included with the 89600 VSA software can be found in the Demo and Recorded Signals topic.

   For more information about your specific measurement hardware, see the Measurement Hardware section of the VSA help.

2. Configure Measurement Setup and Input Parameters

   1. Set the Center Frequency

      By default, the center frequency of each measurement channel must be set to within approximately ±0.5x subcarrier spacing of the carrier frequency of the 5G NR signal connected to that channel, otherwise the demodulator may not be able to lock onto your signal.

      Frequency lock range can be extended to ± 2.5x subcarrier spacing by selecting Extended Freq Lock.

   2. Set the Frequency Span (optional)

      At this point, you can set the frequency span for the signal. The span should be larger than the valid bandwidth of the 5G NR signal.

   3. Configure the Input Range

      The input range must be set correctly to obtain accurate measurements. Input ranges that are too low overload the measurement hardware's ADCAnalog-to-Digital Converter. Input ranges that are too high increase noise, which increases errors reported in error summary data, such as EVMError vector magnitude (EVM): A quality metric in digital communication systems. See the EVM metric in the Error Summary Table topic in each demodulator for more information on how EVM is calculated for that modulation format..

   4. Set up triggering (optional) 

      The default triggering mode is set to "FreeRun." However, you can configure a different type of configuring if it is available. For example, if you have a frame boundary trigger from your device, connect it to the External Trigger of the analyzer, and set this Triggering as “External”. Then go to 5G NR Demod Properties > Time Tab and enable Frame Trigger Is Present. This will decrease the needed data length for the measurement and speed up the measurement.

   5. Verify the input signal and initial parameter settings 

      View your signal in the frequency domain (Spectrum trace) to verify the parameters you set.

3. Configure the 5G NR demodulator

   1. Click MeasSetup > Demodulator > Cellular > 5G NR to enable the 5G NR demodulator properties and measurement parameters.

4. Set up 5G NR signal parameters

   Parts of the 5G NR signal are auto-detectable; however, some parameters will still need to be set for successful autodetection. The 5G NR demodulator also includes predefined test models and 3GPP Conformance Test settings to assist with parameter setup.

5. Run the Measurement

   Press the Restart () button to restart the measurement.

   For help when your signal is not demodulating correctly, see the Troubleshooting topic.

   The VSA software includes a New Radio Speedup macro to help optimize setups for reduced measurement time. Optimization is customizable, and the macro saves a backup of your original setup to take the risk out of experimenting with the macro.

See Also

Troubleshooting

About 5G NR Modulation Analysis

New Radio Speedup Macro