Better?? PSK Modulator??
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@ -51,7 +51,7 @@ public:
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interleaver(baud_rate, interleave_setting, is_frequency_hopping),
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input_data(std::move(_data)),
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mgd_decoder(baud_rate, is_frequency_hopping),
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modulator(PSKModulatorConfig(1500, 48000, baud_rate)) {}
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modulator(48000) {}
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/**
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* @brief Transmits the input data by processing it through different phases like FEC encoding, interleaving, symbol formation, scrambling, and modulation.
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@ -101,7 +101,7 @@ private:
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Scrambler scrambler; ///< Scrambler instance for scrambling the data.
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FECEncoder fec_encoder; ///< FEC encoder instance for encoding the data.
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Interleaver interleaver; ///< Interleaver instance for interleaving the data.
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milstd::PSKModulator modulator; ///< PSK modulator instance for modulating the data.
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PSKModulator modulator; ///< PSK modulator instance for modulating the data.
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MGDDecoder mgd_decoder; ///< MGD decoder
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/**
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@ -1,74 +1,58 @@
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#ifndef PSK_MODULATOR_H
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#define PSK_MODULATOR_H
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#include <array>
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#include <vector>
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#include <cmath>
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#include <cstdint>
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#include <vector>
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#include <stdexcept>
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class PSKModulatorConfig {
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class PSKModulator {
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public:
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int carrier_frequency;
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int sample_rate;
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int baud_rate;
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int bits_per_symbol;
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PSKModulatorConfig(int cf, int sr, int br) : carrier_frequency(cf), sample_rate(sr), baud_rate(br) {}
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};
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namespace milstd {
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class PSKModulator {
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public:
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PSKModulator(const PSKModulatorConfig& config) : carrier_frequency(config.carrier_frequency), sample_rate(config.sample_rate), baud_rate(config.baud_rate) {
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omega = 2.0 * M_PI * carrier_frequency / sample_rate;
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baud_incr = static_cast<double>(baud_rate) / sample_rate;
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phase = 0.0;
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baud_frac = 0.0;
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PSKModulator(double sample_rate) : sample_rate(sample_rate), carrier_freq(1800), phase(0.0) {
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initializeSymbolMap();
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}
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std::vector<int16_t> modulate(const std::vector<uint8_t>& symbol_stream) {
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std::vector<int16_t> modulate(const std::vector<uint8_t>& symbols) {
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std::vector<int16_t> modulated_signal;
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modulated_signal.reserve(static_cast<size_t>(symbol_stream.size() / baud_incr));
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for (uint8_t symbol : symbol_stream) {
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double symbol_phase = symbolMap[symbol];
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while (baud_frac < 1.0) {
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double sample = std::sin(omega * phase + symbol_phase);
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int16_t output_sample = static_cast<int16_t>(sample * 32767);
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modulated_signal.push_back(output_sample);
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phase = std::fmod(phase + omega, 2.0 * M_PI);
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baud_frac += baud_incr;
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const double phase_increment = 2 * M_PI * carrier_freq / sample_rate;
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for (auto symbol : symbols) {
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if (symbol >= symbolMap.size()) {
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throw std::out_of_range("Invalid symbol value for 8-PSK modulation");
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}
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double target_phase = symbolMap[symbol];
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baud_frac -= 1.0;
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for (size_t i = 0; i < samples_per_symbol; ++i) {
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double value = std::sin(phase + target_phase);
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modulated_signal.push_back(static_cast<int16_t>(value * std::numeric_limits<int16_t>::max()));
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phase += phase_increment;
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if (phase >= 2 * M_PI) {
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phase -= 2 * M_PI;
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}
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}
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}
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return modulated_signal;
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}
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private:
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int carrier_frequency;
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int sample_rate;
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int baud_rate;
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double phase;
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double baud_frac;
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double baud_incr;
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double omega;
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std::array<double, 8> symbolMap;
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private:
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double sample_rate; ///< The sample rate of the system.
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double carrier_freq; ///< The frequency of the carrier, set to 1800 Hz as per standard.
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double phase; ///< Current phase of the carrier waveform.
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size_t samples_per_symbol = 40; ///< Number of samples per symbol, calculated to match symbol duration with cycle.
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std::vector<double> symbolMap; ///< The mapping of tribit symbols to phase shifts.
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void initializeSymbolMap() {
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double phase_increment = 2.0 * M_PI / 8.0;
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for (int symbol = 0; symbol < 8; ++symbol) {
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symbolMap[symbol] = symbol * phase_increment;
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}
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}
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symbolMap = {
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0.0, // 0 (000) corresponds to 0 degrees
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M_PI / 4, // 1 (001) corresponds to 45 degrees
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M_PI / 2, // 2 (010) corresponds to 90 degrees
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3 * M_PI / 4, // 3 (011) corresponds to 135 degrees
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M_PI, // 4 (100) corresponds to 180 degrees
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5 * M_PI / 4, // 5 (101) corresponds to 225 degrees
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3 * M_PI / 2, // 6 (110) corresponds to 270 degrees
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7 * M_PI / 4 // 7 (111) corresponds to 315 degrees
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};
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}
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}
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};
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#endif /* PSK_MODULATOR_H */
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#endif
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4
main.cpp
4
main.cpp
@ -19,12 +19,12 @@ int main() {
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size_t baud_rate = 150;
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bool is_voice = false; // False indicates data mode
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bool is_frequency_hopping = false; // Fixed frequency operation
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size_t interleave_setting = 1; // Short interleave
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size_t interleave_setting = 2; // Short interleave
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// Create ModemController instance
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ModemController modem(baud_rate, is_voice, is_frequency_hopping, interleave_setting, bitstream);
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const char* file_name = "modulated_signal_150bps_shortinterleave.wav";
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const char* file_name = "modulated_signal_150bps_longinterleave.wav";
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// Perform transmit operation to generate modulated signal
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std::vector<int16_t> modulated_signal = modem.transmit();
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