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124 lines
3.0 KiB
C++
124 lines
3.0 KiB
C++
// Copyright 2020-2021 Rob Riggs <rob@mobilinkd.com>
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// All rights reserved.
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#pragma once
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#include "ClockRecovery.h"
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#include "Correlator.h"
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#include "DataCarrierDetect.h"
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#include "FirFilter.h"
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#include "FreqDevEstimator.h"
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#include "M17FrameDecoder.h"
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#include "M17Framer.h"
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#include "Util.h"
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#include <algorithm>
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#include <array>
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#include <functional>
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#include <tuple>
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#include "export.h"
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namespace modemm17 {
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struct MODEMM17_API M17Demodulator
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{
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static const uint16_t SAMPLE_RATE = 48000;
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static const uint16_t SYMBOL_RATE = 4800;
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static const uint16_t SAMPLES_PER_SYMBOL = SAMPLE_RATE / SYMBOL_RATE;
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static const uint16_t BLOCK_SIZE = 192;
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static constexpr float sample_rate = SAMPLE_RATE;
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static constexpr float symbol_rate = SYMBOL_RATE;
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static const uint8_t MAX_MISSING_SYNC = 8;
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using collelator_t = Correlator;
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using sync_word_t = SyncWord<collelator_t>;
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using callback_t = M17FrameDecoder::callback_t;
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using diagnostic_callback_t = std::function<void(bool, float, float, float, int, int, float, int, int, int, int)>;
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enum class DemodState {
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UNLOCKED,
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LSF_SYNC,
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STREAM_SYNC,
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PACKET_SYNC,
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BERT_SYNC,
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FRAME
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};
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DataCarrierDetect<SAMPLE_RATE, 500> dcd{2500, 4000, 1.0, 4.0};
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ClockRecovery<SAMPLE_RATE, SYMBOL_RATE> clock_recovery;
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sync_word_t preamble_sync{{+3, -3, +3, -3, +3, -3, +3, -3}, 29.f};
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sync_word_t lsf_sync{ {+3, +3, +3, +3, -3, -3, +3, -3}, 32.f, -31.f}; // LSF or STREAM (inverted)
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sync_word_t packet_sync{ {+3, -3, +3, +3, -3, -3, -3, -3}, 31.f, -31.f}; // PACKET or BERT (inverted)
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FreqDevEstimator dev;
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float idev;
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size_t count_ = 0;
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int8_t polarity = 1;
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M17Framer<368> framer;
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M17FrameDecoder decoder;
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DemodState demodState = DemodState::UNLOCKED;
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M17FrameDecoder::SyncWordType sync_word_type = M17FrameDecoder::SyncWordType::LSF;
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uint8_t sample_index = 0;
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bool dcd_ = false;
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bool need_clock_reset_ = false;
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bool need_clock_update_ = false;
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bool passall_ = false;
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int viterbi_cost = 0;
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int sync_count = 0;
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int missing_sync_count = 0;
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uint8_t sync_sample_index = 0;
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diagnostic_callback_t diagnostic_callback;
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M17Demodulator(callback_t callback) :
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decoder(callback),
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initializing_count_(1920)
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{
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demodState = DemodState::UNLOCKED;
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}
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virtual ~M17Demodulator() {}
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void dcd_on();
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void dcd_off();
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void initialize(const float input);
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void update_dcd();
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void do_unlocked();
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void do_lsf_sync();
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void do_packet_sync();
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void do_stream_sync();
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void do_bert_sync();
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void do_frame(float filtered_sample);
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bool locked() const {
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return dcd_;
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}
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void passall(bool enabled) {
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passall_ = enabled;
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// decoder.passall(enabled);
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}
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void diagnostics(diagnostic_callback_t callback)
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{
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diagnostic_callback = callback;
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}
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void update_values(uint8_t index);
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void operator()(const float input);
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private:
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static const std::array<float, 150> rrc_taps;
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BaseFirFilter<rrc_taps.size()> demod_filter{rrc_taps};
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collelator_t correlator;
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int16_t initializing_count_;
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};
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} // modemm17
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