Overlaid IQ Meas Time (TEDS)

Overlaid IQ Mag Time shows all subcarrier symbols, overlaid on an ideal symbol pattern with circles for data symbols and cross-marks for sync and pilot symbols. Header symbols, coded in QPSK, always appear on the sync/pilot unit circle, regardless of modulation type. By visual inspection, you can view the actual symbol locations versus the ideal state symbol locations. You can modify the ideal symbol pattern and size in the Digital Demod dialog box of the trace properties (Trace > Digital Demod > Ideal State). The ideal symbol locations can only be shown when IQ Normalize is selected.

Select Trace > Auto Scale to scale the trace. If the trace shows NO DATA, check your recorded signal or input signal, and your TEDS demod properties. TEDS demod parameters Droop and Pilot Tracking affect this trace. This display is commonly known as the constellation trace for a measured combined signal (in the above trace, Normal Uplink, 50kHz channel bandwidth, 16QAM modulation).

Select Markers > Show Marker to place a marker on the trace; then review the symbol information in the marker readout window. Once you have a marker on the trace, use your left and right arrow keyboard keys to move the marker through the symbols.

To view this same trace for a selected subcarrier, see IQ Meas Time (Ch1 Subcarr).

To view an ideal composite reference trace, see IQ Ref Time (Overlaid).

See Also

About TEDS Trace Data

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