Obisidian vault auto-backup: 07-01-2026 13:51:56 on . 5 files edited

.obsidian/workspace.json

@@ -219,17 +219,17 @@
   },
   "active": "8beea5ef99c3c6ed",
   "lastOpenFiles": [
+    "ISEN/Traitement du signal/CIPA4/TP/TP4/~WRL0238.tmp",
+    "ISEN/Traitement du signal/CIPA4/TP/TP4/~WRD0235.tmp",
+    "ISEN/Traitement du signal/CIPA4/TP/TP4/~WRL1355.tmp",
+    "ISEN/Traitement du signal/CIPA4/TP/TP4/~WRD1351.tmp",
+    "ISEN/Traitement du signal/CIPA4/TP/TP4/TP4_Experience2.asv",
+    "ISEN/Traitement du signal/CIPA4/TP/TP4/TP4_Experience2.m",
+    "ISEN/Traitement du signal/CIPA4/TP/TP4/Copy_of_TP4_Experience1.m",
     "ISEN/Traitement du signal/CIPA4/TP/TP4/~WRL3213.tmp",
     "ISEN/Traitement du signal/CIPA4/TP/TP4/~WRD3209.tmp",
     "ISEN/Traitement du signal/CIPA4/TP/TP4/TP4_Experience1.m",
     "ISEN/Traitement du signal/CIPA4/TP/TP4/TP3_Experience1.m",
-    "ISEN/Traitement du signal/CIPA4/TP/TP4/~WRL0001.tmp",
-    "ISEN/Traitement du signal/CIPA4/TP/TP4/~WRD0000.tmp",
-    "ISEN/Traitement du signal/CIPA4/TP/TP4/~$P4cipa.doc",
-    "ISEN/Traitement du signal/CIPA4/TP/TP4/TP2425cipaCR.doc",
-    "ISEN/Traitement du signal/CIPA4/TP/TP4/DS2425cipaSACCADE.wav",
-    "ISEN/Traitement du signal/CIPA4/TP/TP4/DS2425cipa9.wav",
-    "ISEN/Traitement du signal/CIPA4/TP/TP4/DS2425cipa8.wav",
     "ISEN/Réseau/CIPA4/TP/TP M02 Conversion.md",
     "Protocol Data Units (PDU).md",
     "ISEN/English/CIPA4/Elevator pitch.md",

ISEN/Traitement du signal/CIPA4/TP/TP4/TP4_Experience1.m

@@ -56,7 +56,7 @@ title('Single-sided amplitude spectrum of y(t)');
 grid on;
 xlim([0 Fs/2]);
 
-% Choose cutoff frequency for baseband, e.g. 5 kHz (adapt after seeing spectrum)
+% Choose cutoff frequency for baseband, e.g. 5 kHz 
 Fc = 5000;                       % cutoff in Hz
 wc = 2*pi*Fc/Fs;                 % digital radian cutoff
 

ISEN/Traitement du signal/CIPA4/TP/TP4/TP4_Experience2.asv

@@ -0,0 +1,55 @@
+%% Experiment 2 : Baseband recovery from TP4cipaQ2.wav
+
+clc;
+clear;
+close all;
+
+%% Load the audio
+[y, Fs] = audioread('TP4cipaQ2.wav');
+if size(y,2) > 1
+    y = mean(y,2);                      % 
+end
+
+N  = length(y);
+
+%% i) Spectre d'amplitude en kHz
+Y  = fft(y);
+magY = abs(Y);
+halfN = floor(N/2)+1;
+magY_half = magY(1:halfN);
+f = (0:halfN-1)*(Fs/N);     % Hz
+f_kHz = f/1000;             % kHz
+
+figure;
+plot(f_kHz, magY_half,'g');
+xlabel('Frequence (kHz)');
+ylabel('|Y(f)|');
+title('Spectre amplitude du signal TP4cipaQ2');
+grid on;
+xlim([0 Fs/2000]);
+
+%% Filtre passe-bas Butterworth pour recuperer la bande de base
+% Choisir une frequence de coupure Fc (en Hz) apres avoir regarde le spectre.
+Fc = 3000;                   % exemple : 3 kHz (a adapter si besoin)
+Wn = Fc/(Fs/2);              % normalisation par Fs/2 [web:237]
+ordre = 4;                   % ordre du filtre (simple mais efficace)
+
+[b,a] = butter(ordre, Wn, 'low');   % filtre passe-bas Butterworth
+
+y_filt = filter(b,a,y);            % signal filtre
+
+%% ii) Spectre du signal filtre
+Yf = fft(y_filt);
+magYf = abs(Yf);
+magYf_half = magYf(1:halfN);
+
+figure;
+plot(f_kHz, magYf_half,'g');
+xlabel('Frequence (kHz)');
+ylabel('|Y_f(f)|');
+title('Spectre amplitude du signal filtre');
+grid on;
+xlim([0 Fs/2000]);
+
+%% iii) Ecouter le signal filtre (a lancer dans MATLAB)
+% sound(y_filt, Fs);

ISEN/Traitement du signal/CIPA4/TP/TP4/TP4_Experience2.m

@@ -0,0 +1,54 @@
+%% Experiment 2 : Baseband recovery from TP4cipaQ2.wav
+
+clc;
+clear;
+close all;
+
+%% Load the audio
+[y, Fs] = audioread('TP4cipaQ2.wav');
+if size(y,2) > 1
+    y = mean(y,2);                      % Switch to mono
+end
+
+N  = length(y);
+
+%% i) Spectre of amplitude in kHz
+Y  = fft(y);
+magY = abs(Y);
+halfN = floor(N/2)+1;
+magY_half = magY(1:halfN);
+f = (0:halfN-1)*(Fs/N);     % Hz
+f_kHz = f/1000;             % kHz
+
+figure;
+plot(f_kHz, magY_half,'g');
+xlabel('Frequence (kHz)');
+ylabel('|Y(f)|');
+title('Spectre amplitude du signal TP4cipaQ2');
+grid on;
+xlim([0 Fs/2000]);
+
+%% Butterworth filter
+
+Fc = 3000;                   
+Wn = Fc/(Fs/2);              
+ordre = 4;                   
+
+[b,a] = butter(ordre, Wn, 'low');  
+
+y_filt = filter(b,a,y);            
+
+%% ii) Spectre of filtered signal
+Yf = fft(y_filt);
+magYf = abs(Yf);
+magYf_half = magYf(1:halfN);
+
+figure;
+plot(f_kHz, magYf_half,'g');
+xlabel('Frequence (kHz)');
+ylabel('|Y_f(f)|');
+title('Spectre amplitude du signal filtre');
+grid on;
+xlim([0 Fs/2000]);
+
+sound(y_filt, Fs);