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more work on DAB decoding
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@AlexandreRouma
AlexandreRouma committed Sep 22, 2024
1 parent 064f25e commit f8078ac
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Showing 6 changed files with 731 additions and 221 deletions.
200 changes: 100 additions & 100 deletions decoder_modules/dab_decoder/src/dab_dsp.h
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Original file line number Diff line number Diff line change
Expand Up @@ -5,139 +5,139 @@
#include "dab_phase_sym.h"

namespace dab {
class CyclicSync : public dsp::Processor<dsp::complex_t, dsp::complex_t> {
using base_type = dsp::Processor<dsp::complex_t, dsp::complex_t>;
public:
CyclicSync() {}
// class CyclicSync : public dsp::Processor<dsp::complex_t, dsp::complex_t> {
// using base_type = dsp::Processor<dsp::complex_t, dsp::complex_t>;
// public:
// CyclicSync() {}

// TODO: The default AGC rate is probably way too fast, plot out the avgCorr to see how much it moves
CyclicSync(dsp::stream<dsp::complex_t>* in, double symbolLength, double cyclicPrefixLength, double samplerate, float agcRate = 1e-3) { init(in, symbolLength, cyclicPrefixLength, samplerate, agcRate); }
// // TODO: The default AGC rate is probably way too fast, plot out the avgCorr to see how much it moves
// CyclicSync(dsp::stream<dsp::complex_t>* in, double symbolLength, double cyclicPrefixLength, double samplerate, float agcRate = 1e-3) { init(in, symbolLength, cyclicPrefixLength, samplerate, agcRate); }

void init(dsp::stream<dsp::complex_t>* in, double symbolLength, double cyclicPrefixLength, double samplerate, float agcRate = 1e-3) {
// Computer the number of samples for the symbol and its cyclic prefix
symbolSamps = round(samplerate * symbolLength);
prefixSamps = round(samplerate * cyclicPrefixLength);
// void init(dsp::stream<dsp::complex_t>* in, double symbolLength, double cyclicPrefixLength, double samplerate, float agcRate = 1e-3) {
// // Computer the number of samples for the symbol and its cyclic prefix
// symbolSamps = round(samplerate * symbolLength);
// prefixSamps = round(samplerate * cyclicPrefixLength);

// Allocate and clear the delay buffer
delayBuf = dsp::buffer::alloc<dsp::complex_t>(STREAM_BUFFER_SIZE + 64000);
dsp::buffer::clear(delayBuf, symbolSamps);
// // Allocate and clear the delay buffer
// delayBuf = dsp::buffer::alloc<dsp::complex_t>(STREAM_BUFFER_SIZE + 64000);
// dsp::buffer::clear(delayBuf, symbolSamps);

// Allocate and clear the history buffer
histBuf = dsp::buffer::alloc<dsp::complex_t>(prefixSamps);
dsp::buffer::clear(histBuf, prefixSamps);
// // Allocate and clear the history buffer
// histBuf = dsp::buffer::alloc<dsp::complex_t>(prefixSamps);
// dsp::buffer::clear(histBuf, prefixSamps);

// Compute the delay input addresses
delayBufInput = &delayBuf[symbolSamps];
// // Compute the delay input addresses
// delayBufInput = &delayBuf[symbolSamps];

// Compute the correlation AGC configuration
this->agcRate = agcRate;
agcRateInv = 1.0f - agcRate;
// // Compute the correlation AGC configuration
// this->agcRate = agcRate;
// agcRateInv = 1.0f - agcRate;

base_type::init(in);
}
// base_type::init(in);
// }

void reset() {
assert(base_type::_block_init);
std::lock_guard<std::recursive_mutex> lck(base_type::ctrlMtx);
base_type::tempStop();
// void reset() {
// assert(base_type::_block_init);
// std::lock_guard<std::recursive_mutex> lck(base_type::ctrlMtx);
// base_type::tempStop();

base_type::tempStart();
}
// base_type::tempStart();
// }

int run() {
int count = base_type::_in->read();
if (count < 0) { return -1; }
// int run() {
// int count = base_type::_in->read();
// if (count < 0) { return -1; }

// Copy the data into the normal delay buffer
memcpy(delayBufInput, base_type::_in->readBuf, count * sizeof(dsp::complex_t));
// // Copy the data into the normal delay buffer
// memcpy(delayBufInput, base_type::_in->readBuf, count * sizeof(dsp::complex_t));

// Flush the input stream
base_type::_in->flush();
// // Flush the input stream
// base_type::_in->flush();

// Do cross-correlation
for (int i = 0; i < count; i++) {
// Get the current history slot
dsp::complex_t* slot = &histBuf[histId++];
// // Do cross-correlation
// for (int i = 0; i < count; i++) {
// // Get the current history slot
// dsp::complex_t* slot = &histBuf[histId++];

// Wrap around the history slot index (TODO: Check that the history buffer's length is correct)
histId %= prefixSamps;
// // Wrap around the history slot index (TODO: Check that the history buffer's length is correct)
// histId %= prefixSamps;

// Kick out last value from the correlation
corr -= *slot;
// // Kick out last value from the correlation
// corr -= *slot;

// Save input value and compute the new prodct
dsp::complex_t val = delayBuf[i];
dsp::complex_t prod = val.conj()*delayBuf[i+symbolSamps];
// // Save input value and compute the new prodct
// dsp::complex_t val = delayBuf[i];
// dsp::complex_t prod = val.conj()*delayBuf[i+symbolSamps];

// Add the new value to the correlation
*slot = prod;
// // Add the new value to the correlation
// *slot = prod;

// Add the new value to the history buffer
corr += prod;
// // Add the new value to the history buffer
// corr += prod;

// Compute sample amplitude
float rcorr = corr.amplitude();
// // Compute sample amplitude
// float rcorr = corr.amplitude();

// If a high enough peak is reached, reset the symbol counter
if (rcorr > avgCorr && rcorr > peakCorr) { // Note keeping an average level might not be needed
peakCorr = rcorr;
peakLCorr = lastCorr;
samplesSincePeak = 0;
}
// // If a high enough peak is reached, reset the symbol counter
// if (rcorr > avgCorr && rcorr > peakCorr) { // Note keeping an average level might not be needed
// peakCorr = rcorr;
// peakLCorr = lastCorr;
// samplesSincePeak = 0;
// }

// If this is the sample right after the peak, save it
if (samplesSincePeak == 1) {
peakRCorr = rcorr;
}
// // If this is the sample right after the peak, save it
// if (samplesSincePeak == 1) {
// peakRCorr = rcorr;
// }

// Write the sample to the output
out.writeBuf[samplesSincePeak++] = val;
// // Write the sample to the output
// out.writeBuf[samplesSincePeak++] = val;

// If the end of the symbol is reached, send it off
if (samplesSincePeak >= symbolSamps) {
if (!out.swap(symbolSamps)) {
return -1;
}
samplesSincePeak = 0;
peakCorr = 0;
}
// // If the end of the symbol is reached, send it off
// if (samplesSincePeak >= symbolSamps) {
// if (!out.swap(symbolSamps)) {
// return -1;
// }
// samplesSincePeak = 0;
// peakCorr = 0;
// }

// Update the average correlation
lastCorr = rcorr;
// // Update the average correlation
// lastCorr = rcorr;

// Update the average correlation value
avgCorr = agcRate*rcorr + agcRateInv*avgCorr;
}
// // Update the average correlation value
// avgCorr = agcRate*rcorr + agcRateInv*avgCorr;
// }

// Move unused data
memmove(delayBuf, &delayBuf[count], symbolSamps * sizeof(dsp::complex_t));
// // Move unused data
// memmove(delayBuf, &delayBuf[count], symbolSamps * sizeof(dsp::complex_t));

return count;
}
// return count;
// }

protected:
int symbolSamps;
int prefixSamps;
// protected:
// int symbolSamps;
// int prefixSamps;

int histId = 0;
dsp::complex_t* histBuf;
// int histId = 0;
// dsp::complex_t* histBuf;

dsp::complex_t* delayBuf;
dsp::complex_t* delayBufInput;
// dsp::complex_t* delayBuf;
// dsp::complex_t* delayBufInput;

dsp::complex_t corr = { 0.0f, 0.0f };
// dsp::complex_t corr = { 0.0f, 0.0f };

int samplesSincePeak = 0;
float lastCorr = 0.0f;
float peakCorr = 0.0f;
float peakLCorr = 0.0f;
float peakRCorr = 0.0f;
// int samplesSincePeak = 0;
// float lastCorr = 0.0f;
// float peakCorr = 0.0f;
// float peakLCorr = 0.0f;
// float peakRCorr = 0.0f;

// Note only required for DAB
float avgCorr = 0.0f;
float agcRate;
float agcRateInv;
};
// // Note only required for DAB
// float avgCorr = 0.0f;
// float agcRate;
// float agcRateInv;
// };

class FrameFreqSync : public dsp::Processor<dsp::complex_t, dsp::complex_t> {
using base_type = dsp::Processor<dsp::complex_t, dsp::complex_t>;
Expand Down
8 changes: 5 additions & 3 deletions decoder_modules/dab_decoder/src/main.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,7 @@
#include <chrono>
#include "dab_dsp.h"
#include <gui/widgets/constellation_diagram.h>
#include "ofdm.h"

#define CONCAT(a, b) ((std::string(a) + b).c_str())

Expand All @@ -35,7 +36,7 @@ class M17DecoderModule : public ModuleManager::Instance {
M17DecoderModule(std::string name) {
this->name = name;

file = std::ofstream("sync4.f32", std::ios::out | std::ios::binary);
file = std::ofstream("sync5.f32", std::ios::out | std::ios::binary);

// Load config
config.acquire();
Expand All @@ -47,7 +48,7 @@ class M17DecoderModule : public ModuleManager::Instance {
vfo->setSnapInterval(250);

// Initialize DSP here
csync.init(vfo->output, 1e-3, 246e-6, INPUT_SAMPLE_RATE);
csync.init(vfo->output, 2048, 504, 1e-3, INPUT_SAMPLE_RATE, 1e-6, 0.01, 0.005);
ffsync.init(&csync.out);
ns.init(&ffsync.out, handler, this);

Expand Down Expand Up @@ -131,8 +132,9 @@ class M17DecoderModule : public ModuleManager::Instance {
std::string name;
bool enabled = true;

dab::CyclicSync csync;
//dab::CyclicSync csync;
dab::FrameFreqSync ffsync;
dsp::ofdm::CyclicTimeSync csync;
dsp::sink::Handler<dsp::complex_t> ns;

ImGui::ConstellationDiagram constDiagram;
Expand Down
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