802.11 Reference Design: Channel Estimate Viewer

This example of the Experiments Framework translates OFDM Rx events from a node log to a MATLAB-compatible format, then displays the logged channel estimates in a MATLAB GUI.

This examples demonstrates how to:

• Read raw log data from an HDF5 file
• Process and filter the log data to construct an array of OFDM Rx events
• Save the Rx events to a MATLAB-compatible HDF5 file
• Load the Rx data into MATLAB
• View the OFDM channel estimates in a MATLAB GUI

This example requires a log file that contains OFDM Rx events. You can generate your own log file (see the Tx/Rx Log Example) or use one of our sample log files.

There are two steps for this example- Python (to convert raw log data to OFDM Rx data) and MATLAB (to read OFDM Rx data and display channel estimates)

Python

The Python script is

will execute the Python script to process the raw log data. By default this script:

• Reads every OFDM Rx event from the log file
• Counts the number of receptions from each unique MAC address
• Creates a new NumPy array containing the OFDM Rx events from the most common source
• Saves this NumPy array to an HDF5 file

To run this example:

• Setup wlan_exp (see Getting Started for details)
• Open a Python shell
• CD to the Python_Reference/Examples/chan_est_viewer directory from the expanded 802.11 Reference design archive
• Run python chan_ests_to_HDF5.py LOG_HDF5_FILE OUTPUT_HDF5_FILE
  • Replace LOG_HDF5_FILE with the raw log file name (XXX if using our sample data)
  • Replace OUTPUT_HDF5_FILE with the name for the new Rx-events-only HDF5 file

• Open MATLAB
• CD to the Python_Reference/Examples/chan_est_viewer directory from the expanded 802.11 Reference design archive
• Run ofdm_chan_est_viewer('OUTPUT_HDF5_FILE'), using the OUTPUT_HDF5_FILE name you chose above

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The latest version of the throughput_two_nodes.py script​ is also shown below.