Subcarrier Error Summary (TEDS)

The subcarrier Error Summary trace shows an error summary for one specific TEDS subcarrier. The specific subcarrier can be selected by using the Analysis Subcarrier drop-down menu. You can choose which symbols to include in this calculation using the Include Sync/Pilot Symbols and Include Header Symbols settings plus the effects of droop using Include Droop and also Pilot Tracking.

The subcarrier Error Summary trace provides the following information:

Parameter

Description

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.

Error Vector Magnitude, in %rms, for the specified subcarrier. The Root Mean Square (rms) of the error vectors is computed and expressed as a percentage of the square root of the mean power of the ideal signal.

EVM Pk

EVM Peak, in %, for the specified subcarrier and the symbol where the peak is located.

Mag Err

I/Q magnitude error, in %rms, for the specified subcarrier. Magnitude error is the difference in amplitude between the I/Q measured signal and the I/Q reference signal and is an indicator of the quality of the modulated signal amplitude component. A high magnitude error might indicate, for example, 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.

Mag Err Pk

Peak I/Q magnitude error, in %, for the specified subcarrier and the symbol where the peak is located.

Phase Err

I/Q phase error, in degrees, for the specified subcarrier. Phase error is the difference in phase between the I/Q measured signal and the I/Q reference signal and is an indicator of the quality of the modulated signal phase component. A high phase error might indicate, for example, incidental FM Frequency Modulation modulation on the signal.

Phase Err Pk

Peak I/Q phase error, in degrees, for the specified subcarrier and the symbol where the peak is located.

Freq Err

Frequency error, in Hertz (or fractions of Hertz), for a specified subcarrier. This value is not subject to the symbols in the EVM calculation or Droop or Pilot Tracking.

Freq Err Pk

Peak frequency error, in Hertz, for the specified subcarrier and the symbol where the peak is located.

IQ Offset

IQ Offset (also called I/Q origin offset) for the specified subcarrier. IQ Offset measures the offset of the subcarrier's constellation from the origin and is expressed in dB units. IQ Offset is averaged over all symbols in the burst.

This value is not subject to the symbols in the EVM calculation or Droop or Pilot Tracking.

Ref Pwr

Average power of the sync and pilot symbols for the specified subcarrier.

Rel Ref Pwr

Reference power relative to the composite reference power. See Error Summary (Composite).

See Also

About TEDS Trace Data