Mag Err (DVB-S2/S2X)

Mag Err is the RMS-average of the IQ magnitude error over all symbol times and expressed as a percentage of 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. Normalization Reference. IQ magnitude errror is the difference in amplitude between the I/Q measured signal and the I/Q reference signal.

The following graphic shows the calculation of IQ magnitude error for a single symbol (the normalization factor in this case is the EVM Normalization Reference).

$image\IQMagIQPhaseError_wmf.jpg$

Magnitude error is an indicator of the quality of the amplitude component of the modulated signal. For example, a very high magnitude error might indicate high incidental AM Amplitude Modulation - CW modulation using amplitude variation in proportion to the amplitude of the modulating signal. Usually taken as DSB-LC for commercial broadcast transmissions and DSB-SC for multiplexed systems. modulation on the signal.

The magnitude error shown in the symbol table is computed only from data at the symbol times (the instant in time when symbols are detected). The computation does not include points between symbols. Therefore, the value of Points / Symbol has no effect on this error data.

The symbol table also shows the symbol that has the largest magnitude error (peak magnitude error).