RMS Error Vector Spectrum (MB-OFDM)
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The composite trace shows the computed difference between IQ Measured vector magnitude and IQ Reference vector magnitude as an RMS average 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. across each subcarrier for all symbols within the Measurement Interval. For example, if the Measurement Interval is setup for (6) symbol-times, then the RMS average EVM is calculated for (6) symbol-times within each of the OFDM Orthogonal Frequency Division Multiplexing: OFDM employs multiple overlapping radio frequency carriers, each operating at a carefully chosen frequency that is Orthogonal to the others, to produce a transmission scheme that supports higher bit rates due to parallel channel operation. OFDM is an alternative tranmission scheme to DSSS and FHSS. subcarriers -61 to -1, and +1 to +61. The RMS reading at the top of the trace displays the number of symbol-times within each OFDM subcarrier used for each RMS calculation. For this example, RMS = 6. This trace displays all occupied bands.
The number of symbol-times included in the corresponds to the settings for Result Length, Measurement Offset, and Measurement Interval. To learn more, see Lengths, Intervals, and Offsets.
To view the computed difference between IQ Measured vector time and IQ Reference vector time, see RMS Error Vector Time.
See Also
Lengths, Intervals, and Offsets (MB-OFDM)
