EVM (Flex Frame)

EVM (Error Vector Magnitude) is the Root Mean Square (RMS) of the error vectors computed and expressed as a percentage of the EVM Normalization Reference.

The error vector magnitude is the length of the vector—at the detected symbol location—which connects the I/Q reference-signal vector to the I/Q measured-signal vector. The following graphic shows the calculation of the EVM metric as well as a diagram showing how a single error vector is calculated.

EVM is calculated from the symbol points (the instant in time when symbols are detected). The computation does not include points between symbols. Therefore Points/Symbol does not affect the value. The Syms/Errs table also shows the location of the symbol that has the largest 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..