%{

Disclaimer:

To run the scripts, the provided traces have to be placed in ./traces, 
e.g. ./traces/2412mhz.mat.

The corresponding subtasks are labeled as % [int]. These labels indicate 
which part of the code or which comment block belongs to the respective 
task.

task1.m
Contains the main calculations needed for Task 1. Some functionality was 
moved into analyzeTrace.m, plotSpectrogram.m, and linearTodB.m, so it can 
also be reused in task4.m. Task 1.5 is not included in the script, because 
it involves interactive marking of transmissions and is therefore only 
documented in the lab report.

task2.m
The textual answers are repeated in the report. Some parts of the MATLAB 
example code were copied to ./from_matlab_example and used to parse the 
frames and decode the beacons.

task3.m
Contains the solution for Task 3. The explanation is further summarized and
abstracted in the report.

task4.m
Uses and adapts the MATLAB example code for OFDM beacon generation. A trace
file is stored in ./traces/wlan_fahren_wir_noch_beacons.mat, containing the
complex baseband vector of the generated beacon waveform. This is done so 
the generated signal can be processed by the helper functions from Task 1 
and plotted in the same way as the provided SDR traces.


Struggles:

I found this lab significantly more difficult and time-consuming than the 
previous two labs. A major part of the effort was not only the 
implementation itself, but also understanding the required background on 
WiFi signals, spectrograms, noise floor estimation, occupancy calculation, 
and beacon frame decoding.
Task 1 in particular was difficult because the instructions were very 
compact and left several implementation details open. Concepts such as 
percentile-based noise floor estimation, channel-wide power aggregation, 
and occupancy thresholds were not immediately clear to me. This caused a 
large amount of debugging, rechecking, and validation.
Another difficulty was that the WiFi background required for the lab was 
quite extensive. Since parts of this topic were covered only during the lab
period, it was hard to apply the concepts confidently from the beginning.
Compared to the previous labs, this task felt much larger in scope and had 
a significantly higher potential for mistakes, while still being part of a 
pass/fail admission requirement. This made the lab feel disproportionate in
effort and risk.
In retrospect, the overall effort was very high. I estimate my total time 
investment at over 30 hours, including background research, implementation,
debugging, interpretation, and report writing.
Despite these difficulties, the lab contributed substantially to my 
understanding of WiFi signal analysis and beacon frame decoding.

%}

task1;
task2;
task3;
task4;