Eq Chan Freq Resp Diff (NB-IoT)
shows the channel response's rate of change with respect to frequency, and is computed by subtracting the channel frequency response from a shifted version of itself (by one subcarrier).
This trace can be used to find the source of a spur or other problem in a signal that causes high EVM Error 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.. When the problem is in the channel (i.e. another transmitter is nearby), both the Error Vector Spectrum and the channel frequency response difference will be affected. When the problem is in the transmitted signal (but not in the channel or in reference signal since the reference signal is used to calculate the channel frequency response), only the will be affected.
To view the equalization frequency response difference for all NRS/Rx paths, see MIMO Eq Chan Freq Resp Diff.
This trace is affected by Averaging.
The trace is not available in uplink when the signal contains only a single tone.
See Also
