Compensate Modulation PRBS (de-rotate) (802.16 OFDMA)

Default: Cleared (See OFDMA Standard Presets Table.)

The default VSA measurement (Compensate Modulation PRBS (de-rotate) shows the IQ symbol pairs for 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. IQ traces (IQ Meas and IQ Ref) as they were applied to the FFT Fast Fourier Transform: A mathematical operation performed on a time-domain signal to yield the individual spectral components that constitute the signal. See Spectrum. bins after modulation PRBS Pseudo-Random Binary Sequence. The Compensate Modulation PRBSparameter removes the modulation PRBS from the OFDM IQ traces. When Compensate Modulation PRBS is selected, the IQ symbol pairs can be viewed as they appear in the FFT bins prior to applying the modulation PRBS.

The displayed symbols on the Syms/Errs trace are defined by mapping the active constellation definition to the IQ Ref trace. Therefore, selecting Compensate Modulation PRBS also affects the displayed symbols on the Syms/Errs trace.