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#include "module_pm_demod.h"
#include "common/dsp/filter/firdes.h"
#include "logger.h"
#include "imgui/imgui.h"
namespace demod
{
PMDemodModule::PMDemodModule(std::string input_file, std::string output_file_hint, nlohmann::json parameters) : BaseDemodModule(input_file, output_file_hint, parameters)
{
// Buffers
sym_buffer = new int8_t[d_buffer_size * 4];
// Parse params
if (parameters.count("resample_after_pll") > 0)
d_resample_after_pll = parameters["resample_after_pll"].get<bool>();
if (parameters.count("pll_bw") > 0)
d_pll_bw = parameters["pll_bw"].get<float>();
else
throw satdump_exception("PLL Bw parameter must be present!");
if (parameters.count("pll_max_offset") > 0)
d_pll_max_offset = parameters["pll_max_offset"].get<float>();
if (parameters.count("rrc_alpha") > 0)
d_rrc_alpha = parameters["rrc_alpha"].get<float>();
else
throw satdump_exception("RRC Alpha parameter must be present!");
if (parameters.count("rrc_taps") > 0)
d_rrc_taps = parameters["rrc_taps"].get<int>();
if (parameters.count("costas_bw") > 0)
d_loop_bw = parameters["costas_bw"].get<float>();
if (parameters.count("clock_gain_omega") > 0)
d_clock_gain_omega = parameters["clock_gain_omega"].get<float>();
if (parameters.count("clock_mu") > 0)
d_clock_mu = parameters["clock_mu"].get<float>();
if (parameters.count("clock_gain_mu") > 0)
d_clock_gain_mu = parameters["clock_gain_mu"].get<float>();
if (parameters.count("clock_omega_relative_limit") > 0)
d_clock_omega_relative_limit = parameters["clock_omega_relative_limit"].get<float>();
if (parameters.count("subcarrier_offset") > 0)
d_subccarier_offset = parameters["subcarrier_offset"].get<uint64_t>();
name = "PM Demodulator";
MAX_SPS = 10; // Here we do NOT want to resample unless really necessary
show_freq = true;
}
void PMDemodModule::init()
{
BaseDemodModule::initb(!d_resample_after_pll);
// PLL
pll = std::make_shared<dsp::PLLCarrierTrackingBlock>(agc->output_stream, d_pll_bw, d_pll_max_offset, -d_pll_max_offset);
// Domain conversion
pm_psk = std::make_shared<dsp::PMToBPSK>(pll->output_stream,
d_resample_after_pll ? d_samplerate : final_samplerate,
d_subccarier_offset == 0 ? d_symbolrate : d_subccarier_offset);
if (d_resample_after_pll)
{
resampler = std::make_shared<dsp::SmartResamplerBlock<complex_t>>(pm_psk->output_stream, final_samplerate, d_samplerate);
// AGC2
agc2 = std::make_shared<dsp::AGCBlock<complex_t>>(resampler->output_stream, 0.001, 1.0, 1.0, 1000.0);
}
// RRC
rrc = std::make_shared<dsp::FIRBlock<complex_t>>(d_resample_after_pll ? agc2->output_stream : pm_psk->output_stream, dsp::firdes::root_raised_cosine(1, final_samplerate, d_symbolrate, d_rrc_alpha, d_rrc_taps));
// Costas
costas = std::make_shared<dsp::CostasLoopBlock>(rrc->output_stream, d_loop_bw, 2);
// Clock recovery
rec = std::make_shared<dsp::MMClockRecoveryBlock<complex_t>>(costas->output_stream, final_sps, d_clock_gain_omega, d_clock_mu, d_clock_gain_mu, d_clock_omega_relative_limit);
}
PMDemodModule::~PMDemodModule()
{
delete[] sym_buffer;
}
void PMDemodModule::process()
{
if (input_data_type == DATA_FILE)
filesize = file_source->getFilesize();
else
filesize = 0;
if (output_data_type == DATA_FILE)
{
data_out = std::ofstream(d_output_file_hint + ".soft", std::ios::binary);
d_output_files.push_back(d_output_file_hint + ".soft");
}
logger->info("Using input baseband " + d_input_file);
logger->info("Demodulating to " + d_output_file_hint + ".soft");
logger->info("Buffer size : %d", d_buffer_size);
time_t lastTime = 0;
// Start
BaseDemodModule::start();
pll->start();
pm_psk->start();
if (d_resample_after_pll)
agc2->start();
rrc->start();
costas->start();
rec->start();
int dat_size = 0;
while (demod_should_run())
{
dat_size = rec->output_stream->read();
if (dat_size <= 0)
{
rec->output_stream->flush();
continue;
}
// Push into constellation
constellation.pushComplex(rec->output_stream->readBuf, dat_size);
// Estimate SNR
snr_estimator.update(rec->output_stream->readBuf, dat_size);
snr = snr_estimator.snr();
if (snr > peak_snr)
peak_snr = snr;
// Update freq
display_freq = dsp::rad_to_hz(pll->getFreq(), final_samplerate);
for (int i = 0; i < dat_size; i++)
{
sym_buffer[i] = clamp(rec->output_stream->readBuf[i].real * 100);
}
rec->output_stream->flush();
if (output_data_type == DATA_FILE)
data_out.write((char *)sym_buffer, dat_size);
else
output_fifo->write((uint8_t *)sym_buffer, dat_size);
if (input_data_type == DATA_FILE)
progress = file_source->getPosition();
// Update module stats
module_stats["snr"] = snr;
module_stats["peak_snr"] = peak_snr;
module_stats["freq"] = display_freq;
if (time(NULL) % 10 == 0 && lastTime != time(NULL))
{
lastTime = time(NULL);
logger->info("Progress " + std::to_string(round(((double)progress / (double)filesize) * 1000.0) / 10.0) + "%%, SNR : " + std::to_string(snr) + "dB," + " Peak SNR: " + std::to_string(peak_snr) + "dB");
}
}
logger->info("Demodulation finished");
if (input_data_type == DATA_FILE)
stop();
}
void PMDemodModule::stop()
{
// Stop
BaseDemodModule::stop();
pll->stop();
pm_psk->stop();
if (d_resample_after_pll)
agc2->stop();
rrc->stop();
costas->stop();
rec->stop();
rec->output_stream->stopReader();
if (output_data_type == DATA_FILE)
data_out.close();
}
std::string PMDemodModule::getID()
{
return "pm_demod";
}
std::vector<std::string> PMDemodModule::getParameters()
{
std::vector<std::string> params = {"rrc_alpha", "rrc_taps", "pll_bw", "pll_max_offset", "costas_bw", "clock_gain_omega", "clock_mu", "clock_gain_mu", "clock_omega_relative_limit"};
params.insert(params.end(), BaseDemodModule::getParameters().begin(), BaseDemodModule::getParameters().end());
return params;
}
std::shared_ptr<ProcessingModule> PMDemodModule::getInstance(std::string input_file, std::string output_file_hint, nlohmann::json parameters)
{
return std::make_shared<PMDemodModule>(input_file, output_file_hint, parameters);
}
}
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