mirror of
https://github.com/f4exb/sdrangel.git
synced 2024-11-08 17:46:03 -05:00
474 lines
16 KiB
C++
474 lines
16 KiB
C++
///////////////////////////////////////////////////////////////////////////////////
|
|
// Copyright (C) 2023 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
|
|
// Copyright (C) 2023 Jon Beniston, M7RCE <jon@beniston.com> //
|
|
// //
|
|
// This program is free software; you can redistribute it and/or modify //
|
|
// it under the terms of the GNU General Public License as published by //
|
|
// the Free Software Foundation as version 3 of the License, or //
|
|
// (at your option) any later version. //
|
|
// //
|
|
// This program is distributed in the hope that it will be useful, //
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of //
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the //
|
|
// GNU General Public License V3 for more details. //
|
|
// //
|
|
// You should have received a copy of the GNU General Public License //
|
|
// along with this program. If not, see <http://www.gnu.org/licenses/>. //
|
|
///////////////////////////////////////////////////////////////////////////////////
|
|
|
|
#include <QDebug>
|
|
|
|
#include <complex.h>
|
|
|
|
#include "dsp/dspengine.h"
|
|
#include "dsp/scopevis.h"
|
|
#include "util/stepfunctions.h"
|
|
#include "util/db.h"
|
|
#include "util/morse.h"
|
|
#include "util/units.h"
|
|
#include "maincore.h"
|
|
|
|
#include "ilsdemod.h"
|
|
#include "ilsdemodsink.h"
|
|
|
|
ILSDemodSink::ILSDemodSink(ILSDemod *ilsDemod) :
|
|
m_spectrumSink(nullptr),
|
|
m_scopeSink(nullptr),
|
|
m_ilsDemod(ilsDemod),
|
|
m_channel(nullptr),
|
|
m_channelSampleRate(ILSDemodSettings::ILSDEMOD_CHANNEL_SAMPLE_RATE),
|
|
m_channelFrequencyOffset(0),
|
|
m_audioSampleRate(0),
|
|
m_magsqSum(0.0f),
|
|
m_magsqPeak(0.0f),
|
|
m_magsqCount(0),
|
|
m_messageQueueToChannel(nullptr),
|
|
m_fftSequence(-1),
|
|
m_fft(nullptr),
|
|
m_fftCounter(0),
|
|
m_squelchLevel(0.001f),
|
|
m_squelchCount(0),
|
|
m_squelchOpen(false),
|
|
m_squelchDelayLine(9600),
|
|
m_volumeAGC(0.003),
|
|
m_audioFifo(48000),
|
|
m_sampleBufferIndex(0)
|
|
{
|
|
m_audioBuffer.resize(1<<14);
|
|
m_audioBufferFill = 0;
|
|
|
|
m_magsq = 0.0;
|
|
|
|
m_sampleBuffer.resize(m_sampleBufferSize);
|
|
m_spectrumSampleBuffer.resize(m_sampleBufferSize);
|
|
|
|
applySettings(m_settings, true);
|
|
applyChannelSettings(m_channelSampleRate, m_channelFrequencyOffset, true);
|
|
|
|
FFTFactory *fftFactory = DSPEngine::instance()->getFFTFactory();
|
|
if (m_fftSequence >= 0) {
|
|
fftFactory->releaseEngine(m_fftSize, false, m_fftSequence);
|
|
}
|
|
m_fftSequence = fftFactory->getEngine(m_fftSize, false, &m_fft);
|
|
m_fftCounter = 0;
|
|
m_fftWindow.create(FFTWindow::Flattop, m_fftSize);
|
|
}
|
|
|
|
ILSDemodSink::~ILSDemodSink()
|
|
{
|
|
}
|
|
|
|
void ILSDemodSink::sampleToScope(Complex sample, Real demod)
|
|
{
|
|
Real r = std::real(sample) * SDR_RX_SCALEF;
|
|
Real i = std::imag(sample) * SDR_RX_SCALEF;
|
|
m_sampleBuffer[m_sampleBufferIndex] = Sample(r, i);
|
|
m_spectrumSampleBuffer[m_sampleBufferIndex] = Sample(demod * SDR_RX_SCALEF, 0);
|
|
m_sampleBufferIndex++;
|
|
|
|
if (m_sampleBufferIndex == m_sampleBufferSize)
|
|
{
|
|
if (m_scopeSink)
|
|
{
|
|
std::vector<SampleVector::const_iterator> vbegin;
|
|
vbegin.push_back(m_sampleBuffer.begin());
|
|
m_scopeSink->feed(vbegin, m_sampleBufferSize);
|
|
}
|
|
if (m_spectrumSink)
|
|
{
|
|
m_spectrumSink->feed(m_spectrumSampleBuffer.begin(), m_spectrumSampleBuffer.end(), false);
|
|
}
|
|
m_sampleBufferIndex = 0;
|
|
}
|
|
}
|
|
|
|
void ILSDemodSink::feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end)
|
|
{
|
|
Complex ci;
|
|
|
|
for (SampleVector::const_iterator it = begin; it != end; ++it)
|
|
{
|
|
Complex c(it->real(), it->imag());
|
|
c *= m_nco.nextIQ();
|
|
|
|
if (m_interpolatorDistance < 1.0f) // interpolate
|
|
{
|
|
while (!m_interpolator.interpolate(&m_interpolatorDistanceRemain, c, &ci))
|
|
{
|
|
processOneSample(ci);
|
|
m_interpolatorDistanceRemain += m_interpolatorDistance;
|
|
}
|
|
}
|
|
else // decimate
|
|
{
|
|
if (m_interpolator.decimate(&m_interpolatorDistanceRemain, c, &ci))
|
|
{
|
|
processOneSample(ci);
|
|
m_interpolatorDistanceRemain += m_interpolatorDistance;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void ILSDemodSink::processOneSample(Complex &ci)
|
|
{
|
|
Complex ca;
|
|
|
|
// Calculate average and peak levels for level meter
|
|
double magsqRaw = ci.real()*ci.real() + ci.imag()*ci.imag();;
|
|
Real magsq = magsqRaw / (SDR_RX_SCALED*SDR_RX_SCALED);
|
|
m_movingAverage(magsq);
|
|
m_magsq = m_movingAverage.asDouble();
|
|
m_magsqSum += magsq;
|
|
if (magsq > m_magsqPeak)
|
|
{
|
|
m_magsqPeak = magsq;
|
|
}
|
|
m_magsqCount++;
|
|
|
|
ci /= SDR_RX_SCALEF;
|
|
|
|
// AM demodulation
|
|
Complex demod = std::abs(ci);
|
|
|
|
// Resample as audio
|
|
if (m_audioInterpolatorDistance < 1.0f) // interpolate
|
|
{
|
|
while (!m_audioInterpolator.interpolate(&m_audioInterpolatorDistanceRemain, demod, &ca))
|
|
{
|
|
processOneAudioSample(ca);
|
|
m_audioInterpolatorDistanceRemain += m_audioInterpolatorDistance;
|
|
}
|
|
}
|
|
else // decimate
|
|
{
|
|
if (m_audioInterpolator.decimate(&m_audioInterpolatorDistanceRemain, demod, &ca))
|
|
{
|
|
processOneAudioSample(ca);
|
|
m_audioInterpolatorDistanceRemain += m_audioInterpolatorDistance;
|
|
}
|
|
}
|
|
|
|
// Decimate again for spectral analysis
|
|
Complex demodDecim;
|
|
if (m_decimator.decimate(demod, demodDecim))
|
|
{
|
|
|
|
// Use FFT to calculate sidebands modulation depth
|
|
m_fft->in()[m_fftCounter] = demodDecim;
|
|
m_fftCounter++;
|
|
if (m_fftCounter == m_fftSize)
|
|
{
|
|
calcDDM();
|
|
m_fftCounter = 0;
|
|
|
|
// Send results to GUI
|
|
if (getMessageQueueToChannel())
|
|
{
|
|
Real modDepth90, modDepth150, sdm, ddm;
|
|
if (m_settings.m_average)
|
|
{
|
|
modDepth90 = m_modDepth90Average.instantAverage();
|
|
modDepth150 = m_modDepth150Average.instantAverage();
|
|
sdm = m_sdmAverage.instantAverage();
|
|
ddm = m_ddmAverage.instantAverage();
|
|
}
|
|
else
|
|
{
|
|
modDepth90 = m_modDepth90;
|
|
modDepth150 = m_modDepth150;
|
|
sdm = m_sdm;
|
|
ddm = m_ddm;
|
|
}
|
|
|
|
Real angle;
|
|
if (m_settings.m_mode == ILSDemodSettings::LOC)
|
|
{
|
|
// For localiser, angle depends on runway length
|
|
// At ILS datum (over threshold) (or ILS point B for short runways (<=1200m), which is 1050m from threshold)
|
|
// the displacement sensitivity is 0.00145 DDM/metre (3.1.3.7)
|
|
// The points at which DDM is 0.155 (i.e a displacement of 0.155/0.00154=~105m) define the course sector (3.1.3.7.3 Note 1)
|
|
// And this must be <= 6 degrees (typically between 3-6degrees) (3.1.3.7.1)
|
|
// Localilzer to threshold distances (geometric angle)
|
|
// EGKK 3150m (3.8deg), EGKB 1840m (6.5deg), EGLL 3960m (3.0deg), EGLC 1570m(27) 1510m(09) (7.6/8deg) EGJJ 1710m (7deg)
|
|
// FAS data for EGJJ https://nats-uk.ead-it.com/cms-nats/export/sites/default/en/Publications/AIP/Current-AIRAC/graphics/196515.pdf
|
|
// LTP (Landing threshold point) 491231.8010N 0021105.6645W = 49.20883361 -2.18490681
|
|
// FPAP 491224.8745N 0021228.7365W = 49.20690958 -2.20798236
|
|
// Length offset 136m (distance from near threshold??)
|
|
// LTP-FPAP=1690m D=1690+305=1995 (GARP is 305m/1000ft from FPAP)
|
|
// EGJJ angle for 1995m = 6deg
|
|
angle = ddm / 0.155f * (m_settings.m_courseWidth / 2.0f);
|
|
}
|
|
else
|
|
{
|
|
// For glide slope, sector is 0.175 DDM = 0.7 degrees
|
|
// Displacement sensitivity 0.0875 at 0.12*theta (0.12*3=0.36deg) (3.1.5.6.2)
|
|
// GP coverage is from 0.45*theta to 1.75*theta (5.25-1.35=4.9deg for 3deg GP)
|
|
angle = 0.12f * m_settings.m_glidePath * ddm / 0.0875f;
|
|
}
|
|
|
|
ILSDemod::MsgAngleEstimate *msg = ILSDemod::MsgAngleEstimate::create(m_powerCarrier, m_power90, m_power150, modDepth90, modDepth150, sdm, ddm, angle);
|
|
getMessageQueueToChannel()->push(msg);
|
|
}
|
|
}
|
|
|
|
// Select signals to feed to scope
|
|
Complex scopeSample;
|
|
switch (m_settings.m_scopeCh1)
|
|
{
|
|
case 0:
|
|
scopeSample.real(ci.real());
|
|
break;
|
|
case 1:
|
|
scopeSample.real(ci.imag());
|
|
break;
|
|
case 2:
|
|
scopeSample.real(demod.real());
|
|
break;
|
|
}
|
|
switch (m_settings.m_scopeCh2)
|
|
{
|
|
case 0:
|
|
scopeSample.imag(ci.real());
|
|
break;
|
|
case 1:
|
|
scopeSample.imag(ci.imag());
|
|
break;
|
|
case 2:
|
|
scopeSample.imag(demod.real());
|
|
break;
|
|
}
|
|
sampleToScope(scopeSample, demod.real());
|
|
}
|
|
|
|
}
|
|
|
|
void ILSDemodSink::processOneAudioSample(Complex &ci)
|
|
{
|
|
Real re = ci.real();
|
|
Real im = ci.imag();
|
|
Real magsq = re*re + im*im;
|
|
m_audioMovingAverage(magsq);
|
|
double magsqAvg = m_movingAverage.asDouble();
|
|
|
|
m_squelchDelayLine.write(magsq);
|
|
|
|
if (magsqAvg < m_squelchLevel)
|
|
{
|
|
if (m_squelchCount > 0) {
|
|
m_squelchCount--;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (m_squelchCount < (unsigned int)m_audioSampleRate / 10) {
|
|
m_squelchCount++;
|
|
}
|
|
}
|
|
|
|
qint16 sample;
|
|
|
|
m_squelchOpen = (m_squelchCount >= (unsigned int)m_audioSampleRate / 20);
|
|
|
|
if (m_squelchOpen && !m_settings.m_audioMute)
|
|
{
|
|
Real demod;
|
|
|
|
{
|
|
demod = sqrt(m_squelchDelayLine.readBack(m_audioSampleRate/20));
|
|
m_volumeAGC.feed(demod);
|
|
demod = (demod - m_volumeAGC.getValue()) / m_volumeAGC.getValue();
|
|
}
|
|
|
|
demod = m_bandpass.filter(demod);
|
|
|
|
Real attack = (m_squelchCount - 0.05f * m_audioSampleRate) / (0.05f * m_audioSampleRate);
|
|
sample = demod * StepFunctions::smootherstep(attack) * (m_audioSampleRate/24) * m_settings.m_volume;
|
|
}
|
|
else
|
|
{
|
|
sample = 0;
|
|
}
|
|
|
|
m_audioBuffer[m_audioBufferFill].l = sample;
|
|
m_audioBuffer[m_audioBufferFill].r = sample;
|
|
++m_audioBufferFill;
|
|
|
|
if (m_audioBufferFill >= m_audioBuffer.size())
|
|
{
|
|
std::size_t res = m_audioFifo.write((const quint8*)&m_audioBuffer[0], std::min(m_audioBufferFill, m_audioBuffer.size()));
|
|
|
|
if (res != m_audioBufferFill)
|
|
{
|
|
qDebug("ILSDemodSink::processOneAudioSample: %lu/%lu audio samples written", res, m_audioBufferFill);
|
|
m_audioFifo.clear();
|
|
}
|
|
|
|
m_audioBufferFill = 0;
|
|
}
|
|
|
|
m_morseDemod.processOneSample(ci);
|
|
}
|
|
|
|
Real ILSDemodSink::magSq(int bin) const
|
|
{
|
|
Complex c = m_fft->out()[bin];
|
|
Real v = c.real() * c.real() + c.imag() * c.imag();
|
|
Real magsq = v / (m_fftSize * m_fftSize);
|
|
return magsq;
|
|
}
|
|
|
|
// Calculate the difference in the depth of modulation (DDM)
|
|
void ILSDemodSink::calcDDM()
|
|
{
|
|
// 3.1.3.5.3 - the modulating tones shall be 90 Hz and 150 Hz within plus or minus 2.5 per cent
|
|
// At 88/92Hz, some energy is lost in adjacent bin, so we use flat top windowing for accurate
|
|
// amplitude measurement, which is what is needed for calculating depth of modulation
|
|
m_fftWindow.apply(m_fft->in());
|
|
|
|
// Perform FFT
|
|
m_fft->transform();
|
|
|
|
// Convert bin to frequency offset
|
|
double frequencyResolution = ILSDemodSettings::ILSDEMOD_SPECTRUM_SAMPLE_RATE / (double)m_fftSize;
|
|
int bin90 = 90.0 / frequencyResolution;
|
|
int bin150 = 150.0 / frequencyResolution;
|
|
|
|
double mag90, mag150;
|
|
double magSqCarrier = magSq(0);
|
|
double magCarrier = sqrt(magSqCarrier);
|
|
|
|
// Add both sidebands
|
|
mag90 = sqrt(magSq(bin90)) + sqrt(magSq(m_fftSize-bin90));
|
|
mag150 = sqrt(magSq(bin150)) + sqrt(magSq(m_fftSize-bin150));
|
|
|
|
// Calculate power in dB
|
|
m_powerCarrier = CalcDb::dbPower(magSqCarrier);
|
|
m_power90 = CalcDb::dbPower(mag90 * mag90);
|
|
m_power150 = CalcDb::dbPower(mag150 * mag150);
|
|
|
|
// Calculate modulation depth as % of carrier
|
|
m_modDepth90 = mag90 / magCarrier * 100.0;
|
|
m_modDepth150 = mag150 / magCarrier * 100.0;
|
|
|
|
// Calculate modulation depth difference (https://www.youtube.com/watch?v=71iww_ERoYc)
|
|
m_ddm = (m_modDepth90 - m_modDepth150) / 100.0;
|
|
|
|
// Calculate sum of difference of modulation
|
|
m_sdm = (m_modDepth90 + m_modDepth150) / 100.0;
|
|
|
|
// Calculate moving averages
|
|
m_modDepth90Average(m_modDepth90);
|
|
m_modDepth150Average(m_modDepth150);
|
|
m_sdmAverage(m_sdm);
|
|
m_ddmAverage(m_ddm);
|
|
}
|
|
|
|
void ILSDemodSink::applyChannelSettings(int channelSampleRate, int channelFrequencyOffset, bool force)
|
|
{
|
|
qDebug() << "ILSDemodSink::applyChannelSettings:"
|
|
<< " channelSampleRate: " << channelSampleRate
|
|
<< " channelFrequencyOffset: " << channelFrequencyOffset;
|
|
|
|
if ((m_channelFrequencyOffset != channelFrequencyOffset) ||
|
|
(m_channelSampleRate != channelSampleRate) || force)
|
|
{
|
|
m_nco.setFreq(-channelFrequencyOffset, channelSampleRate);
|
|
}
|
|
|
|
if ((m_channelSampleRate != channelSampleRate) || force)
|
|
{
|
|
m_interpolator.create(16, channelSampleRate, m_settings.m_rfBandwidth / 2.2);
|
|
m_interpolatorDistance = (Real) channelSampleRate / (Real) ILSDemodSettings::ILSDEMOD_CHANNEL_SAMPLE_RATE;
|
|
m_interpolatorDistanceRemain = m_interpolatorDistance;
|
|
}
|
|
|
|
m_channelSampleRate = channelSampleRate;
|
|
m_channelFrequencyOffset = channelFrequencyOffset;
|
|
|
|
}
|
|
|
|
void ILSDemodSink::applySettings(const ILSDemodSettings& settings, bool force)
|
|
{
|
|
qDebug() << "ILSDemodSink::applySettings:"
|
|
<< " m_rfBandwidth: " << settings.m_rfBandwidth
|
|
<< " m_volume: " << settings.m_volume
|
|
<< " m_squelch: " << settings.m_squelch
|
|
<< " m_audioMute: " << settings.m_audioMute
|
|
<< " m_audioDeviceName: " << settings.m_audioDeviceName
|
|
<< " force: " << force;
|
|
|
|
if ((m_settings.m_squelch != settings.m_squelch) || force) {
|
|
m_squelchLevel = CalcDb::powerFromdB(settings.m_squelch);
|
|
}
|
|
|
|
if ((settings.m_rfBandwidth != m_settings.m_rfBandwidth) || force)
|
|
{
|
|
m_interpolator.create(16, m_channelSampleRate, settings.m_rfBandwidth / 2.2);
|
|
m_interpolatorDistance = (Real) m_channelSampleRate / (Real) ILSDemodSettings::ILSDEMOD_CHANNEL_SAMPLE_RATE;
|
|
m_interpolatorDistanceRemain = m_interpolatorDistance;
|
|
}
|
|
|
|
if ((settings.m_identThreshold != m_settings.m_identThreshold) || force) {
|
|
m_morseDemod.applySettings(settings.m_identThreshold);
|
|
}
|
|
|
|
if (force)
|
|
{
|
|
m_modDepth90Average.reset();
|
|
m_modDepth150Average.reset();
|
|
m_ddmAverage.reset();
|
|
m_decimator.setLog2Decim(ILSDemodSettings::ILSDEMOD_SPECTRUM_DECIM_LOG2);
|
|
}
|
|
|
|
m_settings = settings;
|
|
}
|
|
|
|
void ILSDemodSink::applyAudioSampleRate(int sampleRate)
|
|
{
|
|
if (sampleRate < 0)
|
|
{
|
|
qWarning("ILSDemodSink::applyAudioSampleRate: invalid sample rate: %d", sampleRate);
|
|
return;
|
|
}
|
|
|
|
qDebug("ILSDemodSink::applyAudioSampleRate: sampleRate: %d channelSampleRate: %d", sampleRate, ILSDemodSettings::ILSDEMOD_CHANNEL_SAMPLE_RATE);
|
|
|
|
if (sampleRate != m_audioSampleRate)
|
|
{
|
|
m_audioInterpolator.create(16, ILSDemodSettings::ILSDEMOD_CHANNEL_SAMPLE_RATE, 3500.0f);
|
|
m_audioInterpolatorDistanceRemain = 0;
|
|
m_audioInterpolatorDistance = (Real) ILSDemodSettings::ILSDEMOD_CHANNEL_SAMPLE_RATE / (Real) sampleRate;
|
|
m_bandpass.create(301, sampleRate, 300.0f, 3000.0f);
|
|
//m_bandpass.printTaps("audio_bpf");
|
|
m_audioFifo.setSize(sampleRate);
|
|
m_squelchDelayLine.resize(sampleRate/5);
|
|
|
|
m_volumeAGC.resizeNew(sampleRate/10, 0.003f);
|
|
m_morseDemod.applyChannelSettings(sampleRate);
|
|
}
|
|
|
|
m_audioSampleRate = sampleRate;
|
|
}
|
|
|