diff --git a/lab_4/cfr_comp.svg b/lab_4/cfr_comp.svg
new file mode 100644
index 0000000..174f54b
--- /dev/null
+++ b/lab_4/cfr_comp.svg
@@ -0,0 +1,32251 @@
+
+
+Qt SVG Document
+MATLAB, The MathWorks, Inc. Version 26.1.0.3251617 R2026a Update 2
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Subcarrier index
+
+
+
+
+
+
+0
+
+
+
+500
+
+
+
+1000
+
+
+
+1500
+
+
+
+2000
+
+
+
+2500
+
+
+
+3000
+
+
+
+3500
+
+
+
+4000
+
+
+
+|H[k]|
+
+
+
+
+
+
+0
+
+
+
+0.2
+
+
+
+0.4
+
+
+
+0.6
+
+
+
+0.8
+
+
+
+1
+
+
+
+1.2
+
+
+
+1.4
+
+
+
+1.6
+
+
+
+CFR magnitude for representative packet at 30.0 dB SNR
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Profile A
+
+
+
+Profile B
+
+
+
+Profile C
+
+
+
+Profile D
+
+
+
+
+
+
diff --git a/lab_4/lab_4.m b/lab_4/lab_4.m
index cfb54f5..99e1257 100644
--- a/lab_4/lab_4.m
+++ b/lab_4/lab_4.m
@@ -6,8 +6,10 @@ do_task2 = false;
do_task3_1 = false;
do_task3_2 = false;
do_task3_2_simple_calc = false;
-do_task4_1 = true;
-do_task4_2 = true;
+do_task4_1 = false;
+do_task4_2 = false;
+do_task5_1 = false;
+do_task5_2 = true;
carrier_frequency = 2.4e9;
wifi_be_subcarrier_spacing = 78.125e3;
@@ -111,3 +113,7 @@ end
if do_task4_2
task4;
end
+
+if do_task5_1 || do_task5_2
+ task5;
+end
diff --git a/lab_4/link_level_measurements.md b/lab_4/link_level_measurements.md
index a431ebd..f32c513 100644
--- a/lab_4/link_level_measurements.md
+++ b/lab_4/link_level_measurements.md
@@ -193,4 +193,26 @@ So in this simulation a higher bandwith improves PER.
-## Task 5
\ No newline at end of file
+## Task 5
+
+#### 5.1
+
+
+
+For readability, the labels NTN-TDL-A to NTN-TDL-D are shortened to Profile A to Profile D in the plot.
+
+The channel profile sweep shows that the selected NTN-TDL profile has a visible influence on the PER curve. Profile C performs best in this simulation, while Profile B requires the highest SNR for the same target PER. Around the low-PER region, Profile C reaches a PER of approximately $10^{-3}$ about 5 dB earlier than Profile B. Profiles D and A lie between these two cases, with roughly 1-3 dB spacing between neighboring curves for PER values below $10^{-1}$.
+
+This means that the channel profile changes the effective link robustness even though all other baseline parameters are kept constant. The difference is caused by the different multipath and fading behavior represented by the NTN-TDL profiles.
+
+#### 5.2
+
+
+
+The CFR comparison shows that the NTN-TDL profiles create different frequency-selective channel responses. Profile C has the flattest and highest CFR magnitude at around 1.4 to 1.6 over the active subcarriers, which means that the subcarriers experience a relatively uniform channel gain without strong frequency-selective fades. This is consistent with the PER sweep from Task 5.1, where Profile C performs best.
+
+Profiles A and B show stronger variations and deeper periodic fades over the subcarrier range. These fades reduce the effective SNR on parts of the OFDM spectrum and can therefore increase the packet error probability. Profile D lies between these cases, with visible but more moderate frequency-selective behavior.
+
+Since this plot shows only one representative packet at 30 dB SNR and 320 MHz bandwidth, it should be interpreted qualitatively. It illustrates how the different channel profiles affect the frequency response, while the PER sweep provides the statistical performance comparison.
+
+[This tasks (5.2) interpretation was mainly made from GPT-5.5, because I was not sure what I should assume from the data, after evaluating what GPT interpeted, it made sense and I can see / evaluate the meaning behind the plot]
\ No newline at end of file
diff --git a/lab_4/link_level_measurements.pdf b/lab_4/link_level_measurements.pdf
index a04a67c..466d40b 100644
Binary files a/lab_4/link_level_measurements.pdf and b/lab_4/link_level_measurements.pdf differ
diff --git a/lab_4/per_snr_profile.svg b/lab_4/per_snr_profile.svg
new file mode 100644
index 0000000..41767e3
--- /dev/null
+++ b/lab_4/per_snr_profile.svg
@@ -0,0 +1,754 @@
+
+
+Qt SVG Document
+MATLAB, The MathWorks, Inc. Version 26.1.0.3251617 R2026a Update 2
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+0
+
+
+
+5
+
+
+
+10
+
+
+
+15
+
+
+
+20
+
+
+
+25
+
+
+
+30
+
+
+
+35
+
+
+
+40
+
+
+
+SNR (dB)
+
+
+
+
+
+
+10
+
+
+
+-3
+
+
+
+10
+
+
+
+-2
+
+
+
+10
+
+
+
+-1
+
+
+
+10
+
+
+
+0
+
+
+
+PER
+
+
+
+PER over SNR, Channel Profile Sweep
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Profile A
+
+
+
+Profile B
+
+
+
+Profile C
+
+
+
+Profile D
+
+
+
+
+
+
diff --git a/lab_4/task5.m b/lab_4/task5.m
new file mode 100644
index 0000000..a06b177
--- /dev/null
+++ b/lab_4/task5.m
@@ -0,0 +1,101 @@
+markers = 'ox*sd^v>