Preamble Index Detection Macro (802.16 OFDMA)

(Only applies to 802.16 OFDMA modulation analysis)

The Preamble Index Detection macro (OfdmaPreambleIndexFinder) uses the current measurement setup to search for the correct 802.16 OFDMA Preamble Index value (possible values are 0 to 113).  This macro only applies to measurement setups using 802.16 OFDMA modulation analysis with Downlink analysis enabled.  The macro will start the search from the current Preamble Index value and will continue searching until a successful synchronization occurs or until the set of possible Preamble Index values is exhausted.  The macro progress is reported in the Output window.

The Preamble Index Detection macro can be found in the following location:

%PROGRAMFILES%\Keysight\89600 Software <ReleaseVersion>\89600 VSA Software\Examples\Macros\OfdmaPreambleIndexFinder

The macro relies on a valid measurement configuration being specified. Make sure that the following measurement configuration parameters are correct before attempting to run this macro:

• General settings:

  • Center Frequency

  • Input Range

  • Demodulator (set to 802.16-OFDMA)

• OFDMA Demodulation parameters:

  • Subframe type (set to Downlink)

  • Bandwidth

  • Frame length

To use the Preamble Index detection macro, perform the following procedure sequence:

1. Set the Center frequency to the expected transmitter frequency

2. Set the Input Range to the expected range or use the Autorange functionality of the VSA to set the Input Range automatically.

   The overload message OVx should not be present after making measurements with a correctly ranged measurement configuration.  When the overload message is shown, increase the input range until the message does not show.

3. Select the IEEE Institute of Electrical and Electronics Engineers. A US-based membership organisation that includes engineers, scientists, and students in electronics and related fields. The IEEE developed the 802 series wired and wireless LAN standards. Visit the IEEE at http://www.ieee.org 802.16 OFDMA demodulator.

4. Preset the IEEE 802.16 OFDMA demodulator to the expected signal type (or closest type when no presets match the desired signal).

5. Set the Subframe Type to Downlink

6. Set the Nominal Bandwidth parameter to match the signal

7. Set the Frame Length parameter to match the signal

8. Run the macro by selecting the macro in the Macros dialog and clicking the (Build and) Run button.

   The status of the macro is shown in the Output window. When the macro is successful, the Preamble Index parameter will be updated to match the detected Preamble Index.

   To recall the macro, click Utilities > Macros > Import, navigate to the example macros folder listed above, select the OfdmaPreambleIndexFinder folder, and click Ok.