OFDM Meas (DOCSIS 4.0 Downstream)
When DOCSIS 4.0 Downstream Demodulation is selected, trace is the measured IQ symbol values used to calculate the EVM data results. There is one complex value for each subcarrier for each OFDM symbol in the signal.
You can enable and disable the display of each subcarrier type using the Display Data Subcarriers, Display PLC Data Subcarriers, Display PLC Preamble Subcarriers, and Display Pilot Subcarriers checkboxes on the MeasSetup > Advanced tab.
Trace Color coding Scheme
A multi-color coding scheme is used to make it easy to visually identify common symbols, subcarriers, and data results within various OFDM Traces. This makes cross trace data comparisons and analysis easy to accomplish. Different colors are assigned to symbols representing a common subcarrier type including: Preamble, Pilot, and Data subcarrier types. Some common color scheme Traces include: Error Vector Spectrum, Error Vector Time, and IQ Meas, and OFDM Frame Summary.
You can also customize and re-assign Trace colors schemes, see the Display Preferences Color tab (click tab and select a new color for the active Mod Type element).
- Color
assignments:
- Data color (Mod Type 2)
- PLC Preamble color (Mod Type 4)
- PLC Data color (Mod Type 5)
- Continuous and scattered Pilot color (Mod Type 6)
See Also
