Error Vector Time (Digital Demod)

When Custom IQ is enabled, the Error Vector Time trace shows the time-domain error vector trace data results. This trace contains the computed error vectors between corresponding symbol points in the I/Q measured and I/Q reference signals.

The following graphic shows the calculation of the error vector magnitude (EVM) for a symbol point. The diagram on the right shows how the error vector itself is calculated.

image\EVMrev1_wmf.jpg

If normalization is OFF, the error vector magnitude is shown in units of Volts (normalization factor = 1). If normalization is ON, the error vector magnitude is expressed as a percentage of a normalization factor. See Normalize IQ Traces for more information.

You can set the trace data format to view Error Vector Magnitude, Error Vector Phase, just the I error, or just the Q error. 

Trace Data Formats

It is important to remember that the Error Vector Time trace is a time record made up of complex, time-domain data. Each point in the time record has two components: I and Q. To make sense of the data, select an appropriate trace data format (Trace > Format > Format: drop-down list).