Add ASK BPSK DQPSK(not implemented yet) FFT QPSK WAV

BPSK/bpsk.c

@@ -0,0 +1,199 @@
+#include <stdio.h>
+#include <math.h>
+#include <stdlib.h>
+
+// Fréquence d'échantillonage
+#define FS 44100 
+// Temps d'échantillonage
+#define TS 0.05
+// Nombre d'échantillions
+#define NS (FS*TS)
+// Amplitude du signal
+#define A 32767 
+// Fréquence de la porteuse
+#define FC 400 
+
+// Fonction de concaténation deux tableau
+double* concat_tab(double **t, int a, int b) {
+    double* tf = malloc(sizeof(double) * a * b);
+
+    int pos = 0;
+    for (int i = 0; i < b; i++) {
+        for (int j = 0; j < a; j++) {
+            tf[pos] = t[i][j];
+            pos++;
+        }
+    }
+
+    return tf;
+}
+
+// Fontion permetant la modulation d'un bit
+double* modulation_unique(int b) {
+    double* s = (double*)malloc(NS * sizeof(double));
+
+    // Phase de 0 pour un bit de 0 et phase de pi pour un bit de 1
+    int p = (b == 0) ? 0 : M_PI;
+    
+    for (int n = 0; n < NS; n++) {
+        s[n] = A * cos(2 * M_PI * FC * ((double)n / (double)FS) + p);
+    }
+    return s;
+}
+
+// Fonction permetant la modulation d'un suite de bits
+double* modulation(int* b, int bs) {
+    double** s = (double**)malloc(sizeof(double*) * bs);
+    
+    for (int k = 0; k < bs; k++) {
+        //s[k] = (double*)malloc(sizeof(double) * NS);
+        s[k] = modulation_unique(b[k]);
+    }
+
+    //double* sf = (double*)malloc(sizeof(double) * NS * bs);
+    double *sf = concat_tab(s, NS, bs);
+
+    for (int i = 0; i < bs; i++) {
+        free(s[i]);
+    }
+    free(s);
+
+    return sf;
+}
+
+// Demodulation bpsk en connaissant le nombre d'échantillions et la fréquence de la porteuse (et donc la fréquence d'échantillonage)
+int* demodulation(double* r, int rsize) {
+    int bs = rsize; // A MODIFIER QUAND LE TRUC DU MAIN MARCHERA !
+    int* b = (int*)malloc(sizeof(int) * bs);
+
+    int k = 0, i = 0; 
+    while (i < NS * bs) {
+        double tmp = 0;
+        for (int n = 0; n < NS; n++) {
+            tmp += r[k * (int)NS + n] * cos(2 * M_PI * FC * ((double)n / (double)FS));
+        }
+        // Developper le produit de cos et appliquer un filtre passe bas pour trouver un equivalent de tmp
+        b[k] = (tmp > 0.0) ? 0 : 1;
+        i += NS;
+        k++;
+    }
+    return b;
+}
+
+// Fonction pour écrire un fichier WAV 16 bits PCM
+void write_wav(const char* filename, double* data, int len) {
+    FILE* f = fopen(filename, "wb");
+    if (!f) {
+        return;
+    }
+
+    int32_t chunk_size = 36 + len * 2;
+    int16_t audio_format = 1; // PCM
+    int16_t num_channels = 1;
+    int32_t sample_rate = FS;
+    int32_t byte_rate = FS * num_channels * 2;
+    int16_t block_align = num_channels * 2;
+    int16_t bits_per_sample = 16;
+    int32_t subchunk2_size = len * 2;
+
+    // En-tête WAV
+    fwrite("RIFF", 1, 4, f);
+    fwrite(&chunk_size, 4, 1, f);
+    fwrite("WAVE", 1, 4, f);
+    fwrite("fmt ", 1, 4, f);
+
+    int32_t subchunk1_size = 16;
+    fwrite(&subchunk1_size, 4, 1, f);
+    fwrite(&audio_format, 2, 1, f);
+    fwrite(&num_channels, 2, 1, f);
+    fwrite(&sample_rate, 4, 1, f);
+    fwrite(&byte_rate, 4, 1, f);
+    fwrite(&block_align, 2, 1, f);
+    fwrite(&bits_per_sample, 2, 1, f);
+
+    fwrite("data", 1, 4, f);
+    fwrite(&subchunk2_size, 4, 1, f);
+
+    for (int i = 0; i < len; i++) {
+        int16_t sample = (int16_t)(data[i]);
+        fwrite(&sample, sizeof(int16_t), 1, f);
+    }
+
+    fclose(f);
+}
+
+
+double* read_wav(const char* filename, int* out_len) {
+    FILE* f = fopen(filename, "rb");
+    if (!f) {
+        perror("Erreur ouverture WAV");
+        return NULL;
+    }
+
+    fseek(f, 0, SEEK_END);
+    long filesize = ftell(f);
+    fseek(f, 0, SEEK_SET);
+
+    fseek(f, 44, SEEK_SET);
+
+    int len = (filesize - 44) / 2;
+    double* data = malloc(sizeof(double) * len);
+    int16_t sample;
+
+    for (int i = 0; i < len; i++) {
+        fread(&sample, sizeof(int16_t), 1, f);
+        data[i] = (double)sample;
+    }
+
+    fclose(f);
+
+    *out_len = len;
+    return data;
+}
+
+int main() {
+    int bits[] = {0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1,0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1,0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1,0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1};
+
+    int bs = sizeof(bits) / sizeof(bits[0]);
+
+    for (int i = 0; i < bs; i++) {
+       printf("%d ", bits[i]);
+    }
+    printf("\n");
+
+    double* sf = modulation(bits, bs);
+
+    write_wav("signal.wav", sf, NS * bs);
+    
+    /*
+    FILE *f = fopen("signal.csv", "w");
+
+    if (!f) {
+        perror("Erreur ouverture fichier");
+        free(sf);
+        return 1;
+    }
+
+    for (int i = 0; i < NS * bs; i++) {
+        fprintf(f, "%d,%f\n", i, sf[i]); 
+    }
+
+    fclose(f);
+    */
+
+    // NE MARCHE PAS RENVOIE 1 !
+    //int rsize = (sizeof(sf) / (int)sizeof(sf[0]));
+    
+    int wav_len;
+    double* wav_data = read_wav("signal3.wav", &wav_len);
+
+    int* dbits = demodulation(wav_data, bs);
+
+    for (int i = 0; i < bs; i++) {
+       printf("%d ", dbits[i]);
+    }
+    printf("\n");
+
+    free(sf);
+    return 0;
+}