IQ Ref (802.16 OFDM)
shows the IQ Reference data, with one complex value per subcarrier for each symbol-time in the burst. There may be multiple modulation formats present, in which case the constellation will be an overlay of all formats present. The FCH symbol and all pilots are BPSK Binary phase shift keying - A type of phase modulation using 2 distinct carrier phases to signal ones and zeros., the data modulation is one of BPSK, QPSK Quadrature phase shift keying, 16QAM, or 64QAM and there can be more than one data modulation format.
Normally this trace data is displayed as a constellation. The constellation shows both data and pilot subcarrier symbols. The pilots and data values are shown with different colors.
Pilot BPSK (White)
Burst BPSK (Magenta)
Burst QPSK (Red)
Burst 16QAM (Blue)
Burst 64QAM (Green)
The colors shown on 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. data trace are the same as those on the OFDM Syms/Errs data trace. The individual format colors can be changed in the tab of the dialog box (). The Pilot can be selected by trace ( A-F). The individual formats are listed Mod Type 1 – 12. To change a color, select or (where X is a number 1-12) in the Element scroll text box. Press the button and select a color to associate with the or . See Color Tab for more information.
This is similar to IQ Meas Time (Digital Demod). The difference is that there are 200 values at each symbol-time, rather than just a single value.
See Also
