PLL modif

QAM/debug.py

@@ -4,18 +4,27 @@ from pyqtgraph.Qt import QtWidgets, QtCore
 import numpy as np
 import sys, os
 
+# -------------------- Fichiers de données --------------------
 REF_FILE   = "constellation_ref.dat"
 RX_FILE    = "constellation.dat"
+ERROR_FILE = "pll_error.dat"
 
+# -------------------- Fonctions de chargement --------------------
 def load_points(filename):
     if os.path.exists(filename):
         return np.loadtxt(filename)
     else:
         return np.zeros((0,2))
 
+def load_error(filename):
+    if os.path.exists(filename):
+        return np.loadtxt(filename)
+    else:
+        return np.zeros((0,2))
+
 # -------------------- Application --------------------
 app = QtWidgets.QApplication(sys.argv)
-win = pg.GraphicsLayoutWidget(show=True, title="Constellation Viewer")
+win = pg.GraphicsLayoutWidget(show=True, title="Constellation et PLL Error")
 win.resize(900, 900)
 win.setBackground('#0a0a0a')  # fond noir profond
 
@@ -35,28 +44,36 @@ grid = pg.GridItem()
 grid.setPen(pg.mkPen('#444', width=1, style=QtCore.Qt.DotLine))
 plot.addItem(grid)
 
-# -------------------- Chargement initial des points --------------------
+# -------------------- Chargement initial --------------------
 ref_data = load_points(REF_FILE)
 rx_data  = load_points(RX_FILE)
+error_data = load_error(ERROR_FILE)
 
-# Points sans contour
+# Points référence
 ref_plot = plot.plot(ref_data[:,0], ref_data[:,1],
                      pen=None,
                      symbol='o',
-                     symbolSize=10,             # cercles un peu plus gros
+                     symbolSize=10,
                      symbolBrush=pg.mkBrush('#1E90FF'),  # bleu vif
                      symbolPen=None,
                      name='Référence')
 
+# Points reçus
 rx_plot = plot.plot(rx_data[:,0], rx_data[:,1],
                     pen=None,
                     symbol='x',
-                    symbolSize=6,              # croix plus petites
+                    symbolSize=6,
                     symbolBrush=pg.mkBrush('#FF4500'),  # orange vif
                     symbolPen=None,
                     name='Reçu')
 
-# Légende stylée
+# PLL error en vert
+error_plot = plot.plot(error_data[:,0], error_data[:,1],
+                       pen=pg.mkPen('#00FF00', width=2),
+                       symbol=None,
+                       name='PLL error')
+
+# -------------------- Légende stylée --------------------
 legend = plot.addLegend()
 for item in legend.items:
     item[1].setPen(pg.mkPen('#FFF', width=2))
@@ -65,8 +82,14 @@ for item in legend.items:
 def update():
     ref_data = load_points(REF_FILE)
     rx_data  = load_points(RX_FILE)
+    error_data = load_error(ERROR_FILE)
+    
+    if ref_data.size > 0:
         ref_plot.setData(ref_data[:,0], ref_data[:,1])
+    if rx_data.size > 0:
         rx_plot.setData(rx_data[:,0], rx_data[:,1])
+    if error_data.size > 0:
+        error_plot.setData(error_data[:,0], error_data[:,1])
 
 timer = QtCore.QTimer()
 timer.timeout.connect(update)

QAM/qam.c

@@ -122,10 +122,10 @@ void demodulate(qam_system* qam, double complex* s, int nb_symbols, uint8_t* bit
 }
 
 // PLL pour corriger le déphasage
-void pll_qam_symbol(qam_system* qam, double complex* symbols_rx, double complex* r_corr, int nb_symbols, double Kp, double Ki) {
-
+void pll_qam_symbol(qam_system* qam, double complex* symbols_rx, double complex* r_corr, int nb_symbols, double Kp, double Ki, double alpha, FILE* fp_error) {
     double phase_est = 0.0;
     double integrator = 0.0;
+    double filtered_error = 0.0;
 
     int sm = (int)sqrt(qam->M);
     int N = qam->N;
@@ -134,7 +134,7 @@ void pll_qam_symbol(qam_system* qam, double complex* symbols_rx, double complex*
         double complex r_symbol = 0;
         for (int n = 0; n < N; n++) {
             int idx = k * N + n;
-            r_symbol += symbols_rx[idx] * cexp(2.0 * -I * M_PI * qam->Fc * ((double)idx / qam->Fs));
+            r_symbol += symbols_rx[idx] * cexp(-2.0 * I * M_PI * qam->Fc * ((double)idx / qam->Fs));
         }
         r_symbol /= N;
 
@@ -154,8 +154,15 @@ void pll_qam_symbol(qam_system* qam, double complex* symbols_rx, double complex*
 
         double error = carg(r_symbol * conj(closest));
 
-        integrator += Ki * error;
-        phase_est += Kp * error + integrator;
+        filtered_error = (1.0 - alpha) * filtered_error + alpha * error;
+        integrator += Ki * filtered_error;
+        phase_est += Kp * filtered_error + integrator;
+
+        // Écriture de l'erreur PLL dans le fichier
+        if (fp_error) {
+            fprintf(fp_error, "%d % .8f\n", k, 100 * filtered_error);
+            fflush(fp_error);
+        }
 
         for (int n = 0; n < N; n++) {
             int idx = k * N + n;
@@ -265,7 +272,7 @@ int main () {
     double snr_dB = 5; // SNR en dB
     double snr_lin = pow(10.0, snr_dB / 10.0);
     double sigma = sqrt(signal_power / snr_lin);
-    add_noise(s, total_samples, 20);
+    add_noise(s, total_samples, 10);
 
 
     FILE *fp_ref = fopen("constellation_ref.dat", "w");
@@ -296,9 +303,12 @@ int main () {
     //memmove(s + offset_samples, s, (total_samples - offset_samples) * sizeof(double complex));
 
     double complex* r_corr = malloc(sizeof(double complex) * total_samples);
-    double Kp = 0.25;
+    double Kp = 0.2;
     double Ki = 0.02;
-    pll_qam_symbol(&qam, s, r_corr, nb_symbols, Kp, Ki);
+    double alpha = 0.1;
+    FILE* fp_error = fopen("pll_error.dat", "w");
+    pll_qam_symbol(&qam, s, r_corr, nb_symbols, Kp, Ki, alpha, fp_error);
+    fclose(fp_error);
 
     // Démodulation
     uint8_t* output_bits = (uint8_t*)malloc(nb_bits * sizeof(uint8_t));