Error Vector Time (NB-IoT)

Error Vector Time shows the difference between the measured symbols and the reference symbols for each symbol in the Measurement Interval. The 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. values for subcarriers are plotted above their corresponding symbol-time on this trace. The values of the error vectors are usually plotted as a magnitude, but other formats can be chosen as well.

A marker placed on this trace reads as follows:

indicates that Marker 1 is

on symbol 116
in the NPDSCH_User02 channel allocation shown in the Composite Include list
on subcarrier -4
and has a value of ~0.75%, the RMS average error over all the subcarriers in this symbol being ~0.86% (see EVM for more information on how EVMs are calculated)