ti_mo
66 lines
2.7 KiB
Matlab
66 lines
2.7 KiB
Matlab
%{
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Disclaimer:
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To run the scripts, the provided traces have to be placed in ./traces,
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e.g. ./traces/2412mhz.mat.
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The corresponding subtasks are labeled as % [int]. These labels indicate
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which part of the code or which comment block belongs to the respective
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task.
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task1.m
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Contains the main calculations needed for Task 1. Some functionality was
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moved into analyzeTrace.m, plotSpectrogram.m, and linearTodB.m, so it can
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also be reused in task4.m. Task 1.5 is not included in the script, because
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it involves interactive marking of transmissions and is therefore only
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documented in the lab report.
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task2.m
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The textual answers are repeated in the report. Some parts of the MATLAB
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example code were copied to ./from_matlab_example and used to parse the
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frames and decode the beacons.
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task3.m
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Contains the solution for Task 3. The explanation is further summarized and
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abstracted in the report.
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task4.m
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Uses and adapts the MATLAB example code for OFDM beacon generation. A trace
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file is stored in ./traces/wlan_fahren_wir_noch_beacons.mat, containing the
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complex baseband vector of the generated beacon waveform. This is done so
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the generated signal can be processed by the helper functions from Task 1
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and plotted in the same way as the provided SDR traces.
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Struggles:
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I found this lab significantly more difficult and time-consuming than the
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previous two labs. A major part of the effort was not only the
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implementation itself, but also understanding the required background on
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WiFi signals, spectrograms, noise floor estimation, occupancy calculation,
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and beacon frame decoding.
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Task 1 in particular was difficult because the instructions were very
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compact and left several implementation details open. Concepts such as
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percentile-based noise floor estimation, channel-wide power aggregation,
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and occupancy thresholds were not immediately clear to me. This caused a
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large amount of debugging, rechecking, and validation.
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Another difficulty was that the WiFi background required for the lab was
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quite extensive. Since parts of this topic were covered only during the lab
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period, it was hard to apply the concepts confidently from the beginning.
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Compared to the previous labs, this task felt much larger in scope and had
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a significantly higher potential for mistakes, while still being part of a
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pass/fail admission requirement. This made the lab feel disproportionate in
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effort and risk.
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In retrospect, the overall effort was very high. I estimate my total time
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investment at over 30 hours, including background research, implementation,
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debugging, interpretation, and report writing.
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Despite these difficulties, the lab contributed substantially to my
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understanding of WiFi signal analysis and beacon frame decoding.
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%}
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task1;
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task2;
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task3;
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task4; |