seems finished

lab_3/lab_3.m

@@ -1,4 +1,66 @@
-calculations_only = false;
+%{
+
+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;
+task2;
+task3;
+task4;