Manual Fs/BW Ratio (802.16 OFDM)

Default: See 802.16 OFDM Standard Setups/Presets Table.

Fs/BW is the ratio between OFDM FFT sample rate ("Fs" in the standard) and the nominal channel bandwidth ("BW" in the standard). See Nominal Bandwidth. This ratio is referred to as "n" in the standard. The value is generally a number slightly larger than one.

Specific values supported (via radio buttons) are 8/7, 86/75, 144/125, 316/275, and 57/50.

In addition, arbitrary value between 0.5 and 2 are possible by checking Other and specifying the value in the text box.

The Manual Fs/BW Ratio default is auto-detect based on BW. For auto-detect, the Manual Fs/BW Ratio checkbox is greyed. The image below shows a check in the Manual Fs/BW Ratio checkbox. This will manually override the auto-detect setting. The selected value of the manual Fs/BW Ratio shown here is 8/7, which is the default manual setting.

To select a Fs/BW Ratio manually:

Check the Manual Fs/BW Ratio check box.

Select one of the five preset ratios or Other and enter a value between 0.5 and 2 in the text box.

Check to see if observing other Trace Data graphs demodulates the signal. The IQ Meas or Error Vector Spectrum trace data images are useful. If the signal is demodulated, the Constellation diagram will be correct and the Error Vector Spectrum will show low errors.

See Also

Format Tab (IEEE 802.16 OFDM Demod Properties)

Time and Frequency Parameter Lookup Table (802.16 OFDM)

       

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