/* Fichier d'implémentation de la classe DigitalModulations numériques * - d'amplitude ; * - de fréquence; * - de phase ; * - M-QAM * * Author : Eric Bachard 2026/01/08 18h37 * Licence GPL v2 */ #include #include #include "math.h" #include "imgui.h" #include "imgui_utils.h" #include "vtoggle_button.h" #include "gl_helpers.h" #ifdef M_PI #undef M_PI #define M_PI 3.14159265358979323846f #endif // FIXME image static int my_image_width = 0; static int my_image_height = 0; static GLuint my_image_texture = 0; DigitalModulation::DigitalModulation() : mdWordSize(DEFAULT_WORD_SIZE) { setDigitalModulationType (Amplitude_TAB, MOD_OOK_TYPE); setDigitalModulationType (Frequency_TAB, MOD_FSK_TYPE); setDigitalModulationType (Phase_TAB, MOD_BPSK_TYPE); // TODO Later //setDigitalModulationType (M_QAM_TAB, MOD_M_QAM_TYPE); }; DigitalModulation::~DigitalModulation() { }; short int DigitalModulation::AmplitudeDigitalModulation(float * carrier_freq, int * am_bits, DigitalModulationType * p_aType) { // TODO : améliorer cette partie static DigitalModulationType amplitude_modulation_t = *p_aType; static float c_freq = *carrier_freq; // --------------------- LEFT : SIGNAL ----------------- ImGui::BeginChild("Signal", ImVec2(ImGui::GetContentRegionAvail().x - CHILD2_WIDTH, 0), false); // pour 1 bit, 100 échantillons (400 pour la modulation de fréquence pour fporteuse max) static int samples_per_bit = SAMPLES_PER_BIT_MAX; ImGui::NewLine(); ImGui::SliderFloat("Frequence porteuse ", &c_freq, 2.0f, 10.0f); #if defined(DEBUG) ImGui::SliderInt("Nombre de points par symbole", &samples_per_bit, DEFAULT_SAMPLES_PER_BIT, 500); #endif ImGui::NewLine(); // Surbrillance de la trame affichée highlightFrame(am_bits, getWordSize()); // position du curseur + dimensions du canvas. // canvas_pos contient les coordonnées du curseur (marque l'endroit d'où l'on dessine à ce point du programme) ImVec2 canvas_pos = ImGui::GetCursorScreenPos(); // Dimensions du cadre dans lequel on dessine la sinusoïde ImVec2 canvas_size(ImGui::GetContentRegionAvail().x, CANVAS_HEIGHT); // ce qui va être dessiné ImDrawList* draw_list = ImGui::GetWindowDrawList(); // On dessine un fond blanc draw_list->AddRectFilled ( canvas_pos, ImVec2(canvas_pos.x + canvas_size.x, canvas_pos.y + canvas_size.y), IM_COL32(255,255,255,255) ); // on ajoute par dessus un tour noir draw_list->AddRect ( canvas_pos, ImVec2(canvas_pos.x + canvas_size.x, canvas_pos.y + canvas_size.y), IM_COL32(0,0,0,255) ); // calcul des coordonnées du centre de la frame float center_y = canvas_pos.y + canvas_size.y / 2.0f; // amplitude de la sinusoïde de base float base_amp = SINUS_AMPLITUDE; float total_samples = getWordSize() * samples_per_bit; float dx = canvas_size.x / total_samples; float x = canvas_pos.x; ImVec2 prev(x, center_y); for (int bit_traite = 0; bit_traite < getWordSize(); bit_traite++) { draw_list->AddLine ( ImVec2(x, canvas_pos.y), ImVec2(x, canvas_pos.y + canvas_size.y), IM_COL32(0,120,255,255) ); float amplitude = 0.0f; switch (amplitude_modulation_t) { case MOD_OOK_TYPE: amplitude = am_bits[bit_traite] ? base_amp : 0.0f; break; case MOD_ASK_TYPE: amplitude = am_bits[bit_traite] ? base_amp : base_amp * 0.4f; break; case MOD_MASK_TYPE: if ((bit_traite % 2) == 0) // bit pair => bits 0, 2, 4 ou 6 amplitude = base_amp * (0.25 + 0.5 * am_bits[bit_traite] + 0.25 * am_bits[bit_traite+1]); else // bit impair => bits 1, 3, 5 ou 7 amplitude = base_amp * (0.25 + 0.5 * am_bits[bit_traite-1] + 0.25 * am_bits[bit_traite]); break; default: break; } // on dessine 100 échantillons par bit de la trame for (int i = 0; i < samples_per_bit; i++) { float t = (bit_traite * samples_per_bit + i) / (float)samples_per_bit; float y = center_y - sinf(2.0f * M_PI * c_freq * t) * amplitude; ImVec2 p(x, y); //if (i != (samples_per_bit -1)) // Le dernier raccord peut poser problème dans certains cas // et on ne dessine pas la ligne entre le dernier point du bit précédent // et le premier point du bit suivant. Ceci en M_QAM pour l'instant (pour tester). if (MOD_MASK_TYPE == *p_aType) { if (i != 0) draw_list->AddLine(prev, p, IM_COL32(255,0,0,255), 2.0f); else draw_list->AddLine(p, p, IM_COL32(255,0,0,255), 2.0f); } else draw_list->AddLine(prev, p, IM_COL32(255,0,0,255), 2.0f); prev = p; x += dx; } // FIXME : d'où viennent ces valeurs 5 et 22 ? draw_list->AddText ( ImVec2(x - samples_per_bit * dx + 5, canvas_pos.y + canvas_size.y - 22), IM_COL32(0,0,255,255), am_bits[bit_traite] ? " 1 " : " 0 " ); } ImGui::Dummy(canvas_size); ImGui::NewLine(); ImGui::SeparatorText("Bits"); drawVToggleButtons(am_bits, getWordSize()); ImGui::EndChild(); // ----------------------------- RIGHT : OPTIONS ------------------------ ImGui::SameLine(); ImGui::BeginChild("Options", ImVec2(CHILD2_WIDTH - 8.0f /* minus the border */, 0), true); ImGui::Text("Type de modulation"); ImGui::Separator(); ImGui::RadioButton("OOK " , (int*)&litude_modulation_t, MOD_OOK_TYPE); ImGui::RadioButton("ASK " , (int*)&litude_modulation_t, MOD_ASK_TYPE); ImGui::RadioButton("4-ASK ", (int*)&litude_modulation_t, MOD_MASK_TYPE); // --- AJOUT TÉMOIN --- ImGui::Spacing(); ImGui::Separator(); ImGui::Text("Principe :"); ImGui::Spacing(); ImVec2 ind_size(ImGui::GetContentRegionAvail().x - 10, 50); ImU32 col = IM_COL32(0, 120, 255, 255); // Même bleu que le signal switch(amplitude_modulation_t) { case MOD_OOK_TYPE: case MOD_ASK_TYPE: ImGui::Text("1 bit par symbole"); ImGui::NewLine(); DrawIndicator("Le bit vaut 1 :", &c_freq, &litude_modulation_t, &samples_per_bit, 1.0f, 0.0f, col, ind_size); ImGui::NewLine(); DrawIndicator ("Le bit vaut 0 :", &c_freq, &litude_modulation_t, &samples_per_bit, ((MOD_ASK_TYPE == amplitude_modulation_t) ? 0.4f : 0.0f), 0.0f, col, ind_size ); break; case MOD_MASK_TYPE: ImGui::Text("2 bits par symbole"); ImGui::NewLine(); DrawIndicator("Le symbole vaut 11 : ", &c_freq, &litude_modulation_t, &samples_per_bit, 1.0f, 0.0f, col, ind_size); ImGui::NewLine(); DrawIndicator("Le symbole vaut 10 : ", &c_freq, &litude_modulation_t, &samples_per_bit, 0.75f, 0.0f, col, ind_size); ImGui::NewLine(); DrawIndicator("Le symbole vaut 01 : ", &c_freq, &litude_modulation_t, &samples_per_bit, 0.4f, 0.0f, col, ind_size); ImGui::NewLine(); DrawIndicator("Le symbole vaut 00 : ", &c_freq, &litude_modulation_t, &samples_per_bit, 0.15f, 0.0f, col, ind_size); break; default: break; } // ------- FIN AJOUT TEMOIN ------------- ImGui::EndChild(); return EXIT_SUCCESS; } short int DigitalModulation::FrequencyDigitalModulation(float * carrier_freq, int * fm_bits, DigitalModulationType * fm_type) { static DigitalModulationType frequency_modulation_t = *fm_type; static float c_freq = *carrier_freq; // --------------------- LEFT : SIGNAL ----------------- // FIXME : LAYOUT ImGui::BeginChild("Signal2", ImVec2(ImGui::GetContentRegionAvail().x - CHILD2_WIDTH , 0), false); // pour 1 bit, 100 échantillons (400 donne de meilleurs résultats en MFSK) static int samples_per_bit = SAMPLES_PER_BIT_MAX; // limite le sous-échantillonnage static float k = 2.0f; // default ImGui::NewLine(); // affichage bruité au-delà de 4.0f ImGui::SliderFloat("Frequence porteuse ", carrier_freq, 2.0f, 4.0f); #ifdef DEBUG static int k2 = 2; ImGui::SliderInt("Nombre de points par symbole", &samples_per_bit, DEFAULT_SAMPLES_PER_BIT, 500); ImGui::SliderInt("Rapport fréquence modulée / fréquence de base ", &k2, 4, 10); k = (float)k2; #else k = 2.0f; #endif ImGui::NewLine(); // Surbrillance highlightFrame(fm_bits, getWordSize()); ImVec2 canvas_pos = ImGui::GetCursorScreenPos(); ImVec2 canvas_size(ImGui::GetContentRegionAvail().x, CANVAS_HEIGHT); ImDrawList* draw_list = ImGui::GetWindowDrawList(); draw_list->AddRectFilled ( canvas_pos, ImVec2(canvas_pos.x + canvas_size.x, canvas_pos.y + canvas_size.y), IM_COL32(255,255,255,255) ); draw_list->AddRect ( canvas_pos, ImVec2(canvas_pos.x + canvas_size.x, canvas_pos.y + canvas_size.y), IM_COL32(0,0,0,255) ); float center_y = canvas_pos.y + canvas_size.y / 2.0f; float base_amp = 100.0f; float total_samples = getWordSize() * samples_per_bit; float dx = canvas_size.x / total_samples; float x = canvas_pos.x; ImVec2 prev(x, center_y); for (int bit_traite = 0; bit_traite < getWordSize(); bit_traite++) { draw_list->AddLine ( ImVec2(x, canvas_pos.y), ImVec2(x, canvas_pos.y + canvas_size.y), IM_COL32(0,120,255,255) ); switch (frequency_modulation_t) { case MOD_FSK_TYPE: c_freq = fm_bits[bit_traite] ? (*carrier_freq) * k : *carrier_freq ; break; case MOD_MFSK_TYPE: // On doit dessiner la même amplitude pour les bits (0,1), (2,3), (4,5) et (6,7) // => la parité de bit_traite nous donne la réponse if ((bit_traite % 2) == 0) // bit pair => bits 0, 2, 4 ou 6 c_freq = (*carrier_freq) * ( 1 + k * (2 * fm_bits[bit_traite] + fm_bits[bit_traite+1])); else // bit impair => bits 1, 3, 5 ou 7 c_freq = (*carrier_freq) * ( 1 + k * (2 * fm_bits[bit_traite-1] + fm_bits[bit_traite])); break; default: break; } for (int i = 0; i < samples_per_bit; i++) { float t = (bit_traite * samples_per_bit + i) / (float)samples_per_bit; float y = center_y - sinf(2.0f * M_PI * c_freq * t) * base_amp; ImVec2 p(x, y); draw_list->AddLine(prev, p, IM_COL32(255,0,0,255), 2.0f); prev = p; x += dx; } draw_list->AddText ( ImVec2(x - samples_per_bit * dx + 5, canvas_pos.y + canvas_size.y - 22), IM_COL32(0,0,255,255), fm_bits[bit_traite] ? " 1 " : " 0 " ); } ImGui::Dummy(canvas_size); ImGui::NewLine(); ImGui::SeparatorText("Bits"); drawVToggleButtons(fm_bits, getWordSize()); ImGui::EndChild(); // ----------------------------- RIGHT : OPTIONS ------------------------ ImGui::SameLine(); ImGui::BeginChild("Options", ImVec2(CHILD2_WIDTH - 8.0f, 0), true); ImGui::Text("Type de modulation"); ImGui::Separator(); ImGui::RadioButton("FSK " , (int*)&frequency_modulation_t, MOD_FSK_TYPE); ImGui::RadioButton("4-FSK " , (int*)&frequency_modulation_t, MOD_MFSK_TYPE); // --- AJOUT TÉMOIN --- ImGui::Spacing(); ImGui::Separator(); ImGui::Text("Principe :"); ImGui::Spacing(); ImVec2 ind_size(ImGui::GetContentRegionAvail().x - 10, 50); ImU32 col = IM_COL32(0, 120, 255, 255); // Même bleu que le signal switch(frequency_modulation_t) { case MOD_FSK_TYPE: ImGui::Text("1 bit par symbole"); ImGui::NewLine(); c_freq = (*carrier_freq) * k; DrawIndicator("Le bit vaut 1 :", &c_freq, &frequency_modulation_t, &samples_per_bit, 1.0f, 0.0f, col, ind_size); c_freq = *carrier_freq; ImGui::NewLine(); DrawIndicator ("Le bit vaut 0 :", &c_freq, &frequency_modulation_t, &samples_per_bit, 1.0f, // amplitude 0.0f, // phase col, ind_size ); break; case MOD_MFSK_TYPE: ImGui::Text("2 bits par symbole"); ImGui::NewLine(); c_freq = (*carrier_freq) * 4.0f * k; DrawIndicator("Le symbole vaut 11 : ", &c_freq, &frequency_modulation_t, &samples_per_bit, 1.0f, 0.0f, col, ind_size); ImGui::NewLine(); c_freq = (*carrier_freq) * 2.0f * k; DrawIndicator("Le symbole vaut 10 : ", &c_freq, &frequency_modulation_t, &samples_per_bit, 1.0f, 0.0f, col, ind_size); ImGui::NewLine(); c_freq = (*carrier_freq) * k; DrawIndicator("Le symbole vaut 01 : ", &c_freq, &frequency_modulation_t, &samples_per_bit, 1.0f, 0.0f, col, ind_size); ImGui::NewLine(); c_freq = (*carrier_freq) ; DrawIndicator("Le symbole vaut 00 : ", &c_freq, &frequency_modulation_t, &samples_per_bit, 1.0f, 0.0f, col, ind_size); break; default: break; } // ------- FIN AJOUT TEMOIN ------------- ImGui::EndChild(); return EXIT_SUCCESS; } short int DigitalModulation::PhaseDigitalModulation(float * carrier_freq, int * pm_bits, DigitalModulationType * pm_type) { static DigitalModulationType phase_modulation_t = *pm_type; // --------------------- LEFT : SIGNAL ----------------- ImGui::BeginChild("Signal2", ImVec2(ImGui::GetContentRegionAvail().x - CHILD2_WIDTH , 0), false); static int samples_per_bit = DEFAULT_SAMPLES_PER_BIT; ImGui::NewLine(); ImGui::SliderFloat("Frequence porteuse du signal", carrier_freq, 2.0f, 10.0f); #if defined(DEBUG) ImGui::SliderInt("Nombre de points par symbole", &samples_per_bit, DEFAULT_SAMPLES_PER_BIT, 500); #endif ImGui::NewLine(); // Surbrillance highlightFrame(pm_bits, getWordSize()); ImVec2 canvas_pos = ImGui::GetCursorScreenPos(); ImVec2 canvas_size(ImGui::GetContentRegionAvail().x, CANVAS_HEIGHT); ImDrawList* draw_list = ImGui::GetWindowDrawList(); draw_list->AddRectFilled ( canvas_pos, ImVec2(canvas_pos.x + canvas_size.x, canvas_pos.y + canvas_size.y), IM_COL32(255,255,255,255) ); draw_list->AddRect ( canvas_pos, ImVec2(canvas_pos.x + canvas_size.x, canvas_pos.y + canvas_size.y), IM_COL32(0,0,0,255) ); float center_y = canvas_pos.y + canvas_size.y / 2.0f; float base_amp = 100.0f; float total_samples = getWordSize() * samples_per_bit; float dx = canvas_size.x / total_samples; float x = canvas_pos.x; ImVec2 prev(x, center_y); float phi = 0.0f; float delta_phi = 0.0f; for (int bit_traite = 0; bit_traite < getWordSize(); bit_traite++) { draw_list->AddLine ( ImVec2(x, canvas_pos.y), ImVec2(x, canvas_pos.y + canvas_size.y), IM_COL32(0,120,255,255) ); switch (phase_modulation_t) { case MOD_BPSK_TYPE: phi = pm_bits[bit_traite] ? 0.0f : M_PI; break; case MOD_DPSK_TYPE: if (bit_traite < 1) phi = pm_bits[bit_traite] ? 0.0f : M_PI; else { if ((!pm_bits[bit_traite-1] && pm_bits[bit_traite]) || ((pm_bits[bit_traite-1]) && (pm_bits[bit_traite]))) delta_phi = M_PI; else delta_phi = 0.0f; } phi += delta_phi; break; default: break; } for (int i = 0; i < samples_per_bit; i++) { float t = (bit_traite * samples_per_bit + i) / (float)samples_per_bit; float y = center_y - sinf(2.0f * M_PI * (*carrier_freq) * t + phi) * base_amp; ImVec2 p(x, y); draw_list->AddLine(prev, p, IM_COL32(255,0,0,255), 2.0f); prev = p; x += dx; } draw_list->AddText ( ImVec2(x - samples_per_bit * dx + 5, canvas_pos.y + canvas_size.y - 22), IM_COL32(0,0,255,255), pm_bits[bit_traite] ? " 1 " : " 0 " ); } ImGui::Dummy(canvas_size); ImGui::NewLine(); ImGui::SeparatorText("Bits"); drawVToggleButtons(pm_bits, getWordSize()); ImGui::EndChild(); // ----------------------------- RIGHT : OPTIONS ------------------------ ImGui::SameLine(); ImGui::BeginChild("Options", ImVec2(CHILD2_WIDTH - 8.0f, 0), true); ImGui::Text("Type de modulation"); ImGui::Separator(); ImGui::RadioButton("BPSK " , (int*)&phase_modulation_t, MOD_BPSK_TYPE); ImGui::RadioButton("DPSK " , (int*)&phase_modulation_t, MOD_DPSK_TYPE); // --- AJOUT TÉMOIN --- ImGui::Spacing(); ImGui::Separator(); if (MOD_DPSK_TYPE != phase_modulation_t) ImGui::Text("Principe :"); ImGui::Spacing(); ImVec2 ind_size(ImGui::GetContentRegionAvail().x - 10, 50); ImU32 col = IM_COL32(0, 120, 255, 255); // Même bleu que le signal switch(phase_modulation_t) { case MOD_BPSK_TYPE: ImGui::Text("1 bit par symbole"); ImGui::NewLine(); DrawIndicator("Le bit vaut 1 :", carrier_freq, &phase_modulation_t, &samples_per_bit, 1.0f, // amplitude 0.0f, // phase col, ind_size); ImGui::NewLine(); DrawIndicator ("Le bit vaut 0 :", carrier_freq, &phase_modulation_t, &samples_per_bit, 1.0f, // amplitude M_PI, // phase col, ind_size ); break; case MOD_DPSK_TYPE: ImGui::Text("1 bits par symbole"); ImGui::NewLine(); break; default: break; } // ------- FIN AJOUT TEMOIN ------------- ImGui::EndChild(); return EXIT_SUCCESS; } short int DigitalModulation::M_QAM_DigitalModulation(float * carrier_freq, int * qam_bits, DigitalModulationType * qam_type) { // TODO : améliorer cette partie static DigitalModulationType qam_modulation_t = *qam_type; static float c_freq = *carrier_freq; // --------------------- LEFT : SIGNAL ----------------- ImGui::BeginChild("Signal", ImVec2(ImGui::GetContentRegionAvail().x - CHILD2_WIDTH, 0), false); // pour 1 bit, 100 échantillons (400 pour la modulation de fréquence pour fporteuse max) static int samples_per_bit = SAMPLES_PER_BIT_MAX; ImGui::NewLine(); ImGui::SliderFloat("Frequence porteuse ", &c_freq, 2.0f, 10.0f); #if defined(DEBUG) ImGui::SliderInt("Nombre de points par symbole", &samples_per_bit, DEFAULT_SAMPLES_PER_BIT, 500); #endif ImGui::NewLine(); // Surbrillance de la trame affichée highlightFrame(qam_bits, getWordSize()); // position du curseur + dimensions du canvas. // canvas_pos contient les coordonnées du curseur (marque l'endroit d'où l'on dessine à ce point du programme) ImVec2 canvas_pos = ImGui::GetCursorScreenPos(); // Dimensions du cadre dans lequel on dessine la sinusoïde ImVec2 canvas_size(ImGui::GetContentRegionAvail().x, CANVAS_HEIGHT); // ce qui va être dessiné ImDrawList* draw_list = ImGui::GetWindowDrawList(); // On dessine un fond blanc draw_list->AddRectFilled ( canvas_pos, ImVec2(canvas_pos.x + canvas_size.x, canvas_pos.y + canvas_size.y), IM_COL32(255,255,255,255) ); // on ajoute par dessus un tour noir draw_list->AddRect ( canvas_pos, ImVec2(canvas_pos.x + canvas_size.x, canvas_pos.y + canvas_size.y), IM_COL32(0,0,0,255) ); // calcul des coordonnées du centre de la frame float center_y = canvas_pos.y + canvas_size.y / 2.0f; // amplitude de la sinusoïde de base float base_amp = 100.0f; float total_samples = getWordSize() * samples_per_bit; float dx = canvas_size.x / total_samples; float x = canvas_pos.x; ImVec2 prev(x, center_y); for (int bit_traite = 0; bit_traite < getWordSize(); bit_traite++) { draw_list->AddLine ( ImVec2(x, canvas_pos.y), ImVec2(x, canvas_pos.y + canvas_size.y), IM_COL32(0,120,255,255) ); float amplitude = 0.0f; float coeff_sin = 1.0f; // terme devant le sinus (première fréquence porteuse) float coeff_cos = 1.0f; // terme devant le cosinus (pour la seconde porteuse en quadrature) // Pour la modulation M-QAM, on se place dans le plan complexe. // Cas de la constellation 4-QAM (cas particulier, où elle est identique à la constellation 4-PSK) /* ^ sin | 01 | 11 + | + | ---------------------> cos | + | + 00 | 10 | */ // /!\ LIRE d'abord sin, puis cos ci-dessous !! // 00 -> (-1;-1) / 01 -> (1;-1) / 10 -> (-1;1) / 11 -> (1;1) // ce qui donne les tableaux de coefficients suivants : // tableau des valeurs de sinus const float tab_sinus[4] = { /* 11 */ 1.0f, /* 01 */ 1.0f, /* 10 */-1.0f, /* 00 */-1.0f}; // tableau des valeurs de cosinus const float tab_cosinus[4] = { /* 11 */ 1.0f ,/* 01 */-1.0f, /* 10 */ 1.0f, /* 00 */-1.0f}; // 16-QAM const float tab_sin16[16] = { -3.0f, -1.0f, 3.0f, 1.0f,-3.0f,-1.0f, 3.0f, 1.0f,-3.0f,-1.0f, 3.0f, 1.0f,-3.0f,-1.0f, 3.0f, 1.0f }; const float tab_cos16[16] = { -3.0f, -3.0f,-3.0f,-3.0f,-1.0f,-1.0f,-1.0f,-1.0f, 3.0f, 3.0f, 3.0f, 3.0f, 1.0f, 1.0f, 1.0, 1.0f }; switch (qam_modulation_t) { case MOD_4_QAM_TYPE: // Contraintes : // En MODULATION M-QAM : tous les points sont équi-distants (optimisation du rapport S/(S+B)) // - on doit dessiner le même signal pour les bits (0,1), (2,3), (4,5) et (6,7) // - si le bit testé est pair, alors il s'agit du bit 0, 2, 4 ou 6 // et il faut tester la valeur du mot binaire 2 *bit traite + bit-traite+1 // - si le bit testé est impair, il s'agit du bit 1, 3, 5 ou 7 // et il faut tester la valeur du mot 2 *bit_traite -1 + bit-traite // - ce cas simple nous impose de diviser aussi l'amplitude de base par racine de 2 // (sinon la sinusoïde ne tient pas dans le canvas) // // ce premier calcul nous donne les coefficients devant le sinus ou le cosinus // De plus n doit dessiner le même signal pour les bits (0,1), (2,3), (4,5) et (6,7) // => la parité de bit_traite nous donne les coefficients // Ensuite, Le calcul des coefficients est lié à la valeur des deux bits considérés // L'expression du mot binaire sur 2 bits, nous donne les coefficients // 4 cas sont possibles : 00, 01, 10 et 11, cf la constellation + haut. amplitude = 0.707f * base_amp; if ((bit_traite % 2) == 0) // bit pair => bits 0, 2, 4 ou 6 { coeff_sin = tab_sinus[2*qam_bits[bit_traite]+qam_bits[bit_traite+1]]; coeff_cos = tab_cosinus[2*qam_bits[bit_traite]+qam_bits[bit_traite+1]]; } else // bit impair => bits 1, 3, 5 ou 7 { coeff_sin = tab_sinus[2*qam_bits[bit_traite-1]+qam_bits[bit_traite]]; coeff_cos = tab_cosinus[2*qam_bits[bit_traite-1]+qam_bits[bit_traite]]; } break; case MOD_16_QAM_TYPE: // On code cette fois chaque symbole sur 4 bits // La constellation est la suivante // (+ toutes les permutations circulaire et symétries possibles !!) : // // 0010 0110 | 1110 1010 // | // 0011 0111 | 1111 1011 // ___-3___-1 _|__ 1____3__ // 0001 0101 | 1101 1001 // | // 0000 0100 | 1100 1000 // | // Horizontalement et verticalement, 4 valeurs possibles: // -3 -1, 1 et 3 pour les 2 sinusoïdes, ce qui donne les 16 cas // 16 coefficients pour cos et sin : // Exemple : on codera 0011 (MSB = 0, LSB = 1 ici), avec les amplitudes -3 pour le cos et +1 pour le sin // etc // De plus il faudra tester le bit traité module 4 // On normalise l'amplitude : la plus grande pouvant valoir 3 x 1.414 ~ 4.24 amplitude = base_amp/4.24f; if ((bit_traite % 4 ) == 0) // bit 0 modulo 4 (0,4,8,12,16 ...) { coeff_sin = tab_sin16[8*qam_bits[bit_traite]+4*qam_bits[bit_traite+1]+2*qam_bits[bit_traite+2] + qam_bits[bit_traite+3]]; coeff_cos = tab_cos16[8*qam_bits[bit_traite]+4*qam_bits[bit_traite+1]+2*qam_bits[bit_traite+2] + qam_bits[bit_traite+3]]; } else if ((bit_traite % 4 ) == 1) // bit 1 modulo 4 (1,5,9,13,17 ...) { coeff_sin = tab_sin16[8*qam_bits[bit_traite-1]+4*qam_bits[bit_traite] + 2*qam_bits[bit_traite+1] + qam_bits[bit_traite+2]]; coeff_cos = tab_cos16[8*qam_bits[bit_traite-1]+4*qam_bits[bit_traite] + 2*qam_bits[bit_traite+1] + qam_bits[bit_traite+2]]; } else if ((bit_traite % 4 ) == 2) // bit 2 modulo 4 (2,6,10,14,18 ...) { coeff_sin = tab_sin16[8*qam_bits[bit_traite-2]+4*qam_bits[bit_traite-1]+2*qam_bits[bit_traite] + qam_bits[bit_traite+1]]; coeff_cos = tab_cos16[8*qam_bits[bit_traite-2]+4*qam_bits[bit_traite-1]+2*qam_bits[bit_traite] + qam_bits[bit_traite+1]]; } else if ((bit_traite % 4 ) == 3) // bit 3 [modulo 4] (3,7,11,15 ...) { coeff_sin = tab_sin16[8*qam_bits[bit_traite-3]+4*qam_bits[bit_traite-2]+2*qam_bits[bit_traite-1]+ qam_bits[bit_traite]]; coeff_cos = tab_cos16[8*qam_bits[bit_traite-3]+4*qam_bits[bit_traite-2]+2*qam_bits[bit_traite-1]+ qam_bits[bit_traite]]; } default: break; } // on dessine 100 échantillons par bit de la trame for (int i = 0; i < samples_per_bit; i++) { float t = (bit_traite * samples_per_bit + i) / (float)samples_per_bit; float y = center_y - (coeff_sin * sinf(2.0f * M_PI * c_freq * t) + coeff_cos * cosf(2.0f * M_PI * c_freq * t)) * amplitude; ImVec2 p(x, y); //if (i != (samples_per_bit -1)) // Le dernier raccord peut poser problème dans certains cas // et on ne dessine pas la ligne entre le dernier point du bit précédent // et le premier point du bit suivant. Ceci en M_QAM pour l'instant (pour tester). if (MOD_M_QAM_TYPE == *qam_type) { if (i != 0) draw_list->AddLine(prev, p, IM_COL32(255,0,0,255), 2.0f); else draw_list->AddLine(p, p, IM_COL32(255,0,0,255), 2.0f); } else draw_list->AddLine(prev, p, IM_COL32(255,0,0,255), 2.0f); prev = p; x += dx; } // FIXME : d'où viennent ces valeurs 5 et 22 ? draw_list->AddText ( ImVec2(x - samples_per_bit * dx + 5, canvas_pos.y + canvas_size.y - 22), IM_COL32(0,0,255,255), qam_bits[bit_traite] ? " 1 " : " 0 " ); } ImGui::Dummy(canvas_size); ImGui::NewLine(); ImGui::SeparatorText("Bits"); drawVToggleButtons(qam_bits, getWordSize()); ImGui::EndChild(); // ----------------------------- RIGHT : OPTIONS ------------------------ ImGui::SameLine(); ImGui::BeginChild("Options", ImVec2(CHILD2_WIDTH - 8.0f /* minus the border */, 0), true); ImGui::Text("Type de modulation"); ImGui::Separator(); ImGui::RadioButton("4-QAM (= 4-PSK)" , (int*)&qam_modulation_t, MOD_4_QAM_TYPE); ImGui::RadioButton("16-QAM " , (int*)&qam_modulation_t, MOD_16_QAM_TYPE); // --- AJOUT TÉMOIN --- ImGui::Spacing(); ImGui::Separator(); ImGui::Text("Principe :"); ImGui::Spacing(); ImVec2 ind_size(ImGui::GetContentRegionAvail().x - 10, 50); ImU32 col = IM_COL32(0, 120, 255, 255); // Même bleu que le signal switch(qam_modulation_t) { case MOD_4_QAM_TYPE: ImGui::Text("2 bits par symbole"); ImGui::NewLine(); // Use 4-QAM rules DrawIndicator("Le symbole vaut 11 : ", &c_freq, &qam_modulation_t, &samples_per_bit, 1.0f, -3.0f * M_PI/4.0f, col, ind_size); ImGui::NewLine(); DrawIndicator("Le symbole vaut 10 : ", &c_freq, &qam_modulation_t, &samples_per_bit, 1.0f, 3.0f * M_PI/4.0f, col, ind_size); ImGui::NewLine(); DrawIndicator("Le symbole vaut 01 : ", &c_freq, &qam_modulation_t, &samples_per_bit, 1.0f, -M_PI/4.0f, col, ind_size); ImGui::NewLine(); DrawIndicator("Le symbole vaut 00 : ", &c_freq, &qam_modulation_t, &samples_per_bit, 1.0f, M_PI/4.0f, col, ind_size); break; case MOD_16_QAM_TYPE: ImGui::Text("4 bits par symbole"); ImGui::NewLine(); ImGui::Text("Constellation 16-QAM : "); LoadTextureFromFile("../images/Constellation_modulation_numerique_16_QAM.jpg", &my_image_texture, &my_image_width, &my_image_height); ImGui::Image((ImTextureID)(intptr_t)my_image_texture, ImVec2((float)ImGui::GetWindowSize().x - 18.0f, (float)ImGui::GetWindowSize().x - 18.0f)); break; default: break; } // ------- FIN AJOUT TEMOIN ------------- ImGui::EndChild(); return EXIT_SUCCESS; } void DigitalModulation::setDigitalModulationType(TAB_Name aTab, DigitalModulationType aType) { switch (aTab) { case Amplitude_TAB: md_AM_DigitalModulation_t = aType; break; case Frequency_TAB: md_FM_DigitalModulation_t = aType; break; case Phase_TAB: md_PM_DigitalModulation_t = aType; break; case M_QAM_TAB: md_M_QAM_DigitalModulation_t = aType; break; default: break; } }