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Impl task1 some part of task2

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ti_mo
2026-05-19 21:56:06 +02:00
parent fca31532d1
commit 1561016689
8 changed files with 849 additions and 187 deletions
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lab_3/task1.asv
-116
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@@ -1,116 +0,0 @@
trace1 = load("traces/2412mhz.mat", "iq");
trace2 = load("traces/2432mhz.mat", "iq");
trace3 = load("traces/2452mhz.mat", "iq");
trace4 = load("traces/2472mhz.mat", "iq");
window = 512;
overlap = 64;
fft_precision = 2048;
sample_rate = 20e6; % 20 MS/s
% 1.
duration1 = length(trace1.iq) / sample_rate;
duration2 = length(trace2.iq) / sample_rate;
duration3 = length(trace3.iq) / sample_rate;
duration4 = length(trace4.iq) / sample_rate;
% 2.
% get all four plot values
[~,F1,T1,P1] = spectrogram(trace1.iq, window, overlap, fft_precision, sample_rate, "centered", "psd");
[~,F2,T2,P2] = spectrogram(trace2.iq, window, overlap, fft_precision, sample_rate, "centered", "psd");
[~,F3,T3,P3] = spectrogram(trace3.iq, window, overlap, fft_precision, sample_rate, "centered", "psd");
[~,F4,T4,P4] = spectrogram(trace4.iq, window, overlap, fft_precision, sample_rate, "centered", "psd");
% begin calibrated color scale
P1_dB = 10 * log10(P1);
P2_dB = 10 * log10(P2);
P3_dB = 10 * log10(P3);
P4_dB = 10 * log10(P4);
all_P_dB = [P1_dB(:); P2_dB(:); P3_dB(:); P4_dB(:)];
p_dB_min = min(all_P_dB) - 20;
p_dB_max = max(all_P_dB) + 20;
% end power calibrated color scale
% plot all figures like example shows
figure(1);
imagesc(T1, F1, P1_dB);
axis ij;
xlabel("Time [s]");
ylabel("Freq. [Hz]");
title("Spectrogram Trace 1");
cb = colorbar;
ylabel(cb, "Power [dB]");
clim([p_dB_min p_dB_max]);
xlim([0 0.05]);
figure(2);
imagesc(T2, F2, P2_dB);
axis ij;
xlabel("Time [s]");
ylabel("Freq. [Hz]");
title("Spectrogram Trace 2");
cb = colorbar;
ylabel(cb, "Power [dB]");
clim([p_dB_min p_dB_max]);
xlim([0 0.05]);
figure(3);
imagesc(T3, F3, P3_dB);
axis ij;
xlabel("Time [s]");
ylabel("Freq. [Hz]");
title("Spectrogram Trace 3");
cb = colorbar;
ylabel(cb, "Power [dB]");
clim([p_dB_min p_dB_max]);
xlim([0 0.05]);
figure(4);
imagesc(T4, F4, P4_dB);
axis ij;
xlabel("Time [s]");
ylabel("Freq. [Hz]");
title("Spectrogram Trace 4");
cb = colorbar;
ylabel(cb, "Power [dB]");
clim([p_dB_min p_dB_max]);
xlim([0 0.05]);
% 3.
noise_floor1 = prctile(P1_dB(:), 10);
noise_floor2 = prctile(P2_dB(:), 10);
noise_floor3 = prctile(P3_dB(:), 10);
noise_floor4 = prctile(P4_dB(:), 10);
% 4.
occupancy1 = sum(P1_dB(:) > noise_floor1 + 10) / numel(P1_dB) * 100;
occupancy2 = sum(P2_dB(:) > noise_floor2 + 10) / numel(P2_dB) * 100;
occupancy3 = sum(P3_dB(:) > noise_floor3 + 10) / numel(P3_dB) * 100;
occupancy4 = sum(P4_dB(:) > noise_floor4 + 10) / numel(P4_dB) * 100;
occupancies = [occupancy1 occupancy2 occupancy3 occupancy4];
channels = [1 5 9 13];
[occupancy_max, max_idx] = max(occupancies);
busiest_channel = channels(max_idx);
disp("Results:" + newline)
disp("-- Trace duration ---")
disp("Channel 1 duration: " + duration1 + "s")
disp("Channel 5 duration: " + duration2 + "s")
disp("Channel 9 duration: " + duration3 + "s")
disp("Channel 13 duration: " + duration4 + "s" + newline)
disp("--- Noise floor ---")
disp("Destinct:")
disp("Channel 1 noise floor: " + noise_floor1 + "dB")
disp("Channel 5 noise floor: " + noise_floor2 + "dB")
disp("Channel 9 noise floor: " + noise_floor3 + "dB")
disp("Channel 13 noise floor: " + noise_floor4 + "dB" )
disp(newline)
disp("Combined:")
disp("Channel all noise floor: " + sum([noise_floor1 noise_floor2, noise_floor3, noise_floor4]) / 4 + "dB")