Data Subcarrier Modulation Format (802.16 OFDM)

Menu Path: MeasSetup > IEEE 802.16 OFDM Demod Properties > Format tab

Default: See 802.16 OFDM Standard Setups/Presets Table.

This parameter controls how the modulation format 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. data subcarriers is determined. There are three selections: Automatic, From FCH and Manual. The default is Automatic.

• Automatic - the data modulation format is detected by examining the IQ data in each OFDM symbol. (Modulation changes in the downlink subframe can be tracked.)
• From FCH - the data modulation format is read from the FCH symbol at the start of the downlink subframe. If this parameter is set to FCH and no FCH symbol is detected, then the Automatic demodulation will be used.
• Manual - the data modulation format is specified by the format selected in the text box. When Manual is selected, the subcarrier modulation format can manually be specified. The VSA ignores the format transmitted in the 802.16 OFDM burst and sets the VSAs demodulator to the modulation format specified in the Manual text box.

The modulation format is shown in the Subframe Info trace data.

See Data Subcarrier Modulation for more information.

See Also

Format tab (IEEE 802.16 OFDM Demod Properties)