Syms/Errs (802.16 OFDM)

The Syms/Errs (Symbols/Errors) trace is split into two halves, the top showing an Error Summary and the bottom showing the raw 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. detected symbols. The symbols are the bits detected directly from the constellation diagram, without any de-interleave, decoding or descrambling. The error summary is discussed in a separate Error Info section below.

The values of the individual symbols appear in the bottom half of the trace data in format colors chosen for each format. Default format colors are as follows:

Pilot BPSK Binary phase shift keying - A type of phase modulation using 2 distinct carrier phases to signal ones and zeros. (White)

Burst BPSK (Magenta)

Burst QPSK Quadrature phase shift keying (Red)

Burst 16QAM (Blue)

Burst 64QAM (Green)

The colors shown on the OFDM Syms/Errors are the same as those on the OFDM IQ Meas data trace. The individual format colors can be changed changed in the Color tab of the Display Preferences dialog box (Utilities > Display Preferences > Color). The Pilot can be selected by trace (A-F). The individual formats are listed Mod Type 1 – 12. To change a color, select Pilot or Mod Type X (where X is a number from 1 - 12) in the Element scroll text box. Press the Color button and select a color to associate with the Pilot or Mod Type. See Color Tab for more information.