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Channel analyzer NG and Projector: PSK symbol mapping projection

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This commit is contained in:
f4exb 2018-05-22 13:54:01 +02:00
parent c69d203bd0
commit 85df6218de
3 changed files with 122 additions and 0 deletions

113
sdrbase/dsp/projector.cpp
View File

@ -15,6 +15,7 @@
// along with this program. If not, see <http://www.gnu.org/licenses/>. //
///////////////////////////////////////////////////////////////////////////////////
#include <math.h>
#include "projector.h"
Projector::Projector(ProjectionType projectionType) :
@ -77,6 +78,106 @@ Real Projector::run(const Sample& s)
v = dPhi;
}
break;
case ProjectionBPSK:
{
Real arg = std::atan2((float) s.m_imag, (float) s.m_real);
v = normalizeAngle(2*arg) / (2.0*M_PI); // generic estimation around 0
// mapping on 2 symbols
if (arg < -M_PI/2) {
v -= 1.0/2;
} else if (arg < M_PI/2) {
v += 1.0/2;
} else if (arg < M_PI) {
v -= 1.0/2;
}
}
break;
case ProjectionQPSK:
{
Real arg = std::atan2((float) s.m_imag, (float) s.m_real);
v = normalizeAngle(4*arg) / (4.0*M_PI); // generic estimation around 0
// mapping on 4 symbols
if (arg < -3*M_PI/4) {
v -= 3.0/4;
} else if (arg < -M_PI/4) {
v -= 1.0/4;
} else if (arg < M_PI/4) {
v += 1.0/4;
} else if (arg < 3*M_PI/4) {
v += 3.0/4;
} else if (arg < M_PI) {
v -= 3.0/4;
}
}
break;
case Projection8PSK:
{
Real arg = std::atan2((float) s.m_imag, (float) s.m_real);
v = normalizeAngle(8*arg) / (8.0*M_PI); // generic estimation around 0
// mapping on 8 symbols
if (arg < -7*M_PI/8) {
v -= 7.0/8;
} else if (arg < -5*M_PI/8) {
v -= 5.0/8;
} else if (arg < -3*M_PI/8) {
v -= 3.0/8;
} else if (arg < -M_PI/8) {
v -= 1.0/8;
} else if (arg < M_PI/8) {
v += 1.0/8;
} else if (arg < 3*M_PI/8) {
v += 3.0/8;
} else if (arg < 5*M_PI/8) {
v += 5.0/8;
} else if (arg < 7*M_PI/8) {
v += 7.0/8;
} else if (arg < M_PI) {
v -= 7.0/8;
}
}
break;
case Projection16PSK:
{
Real arg = std::atan2((float) s.m_imag, (float) s.m_real);
v = normalizeAngle(16*arg) / (16.0*M_PI); // generic estimation around 0
// mapping on 16 symbols
if (arg < -15*M_PI/16) {
v -= 15.0/16;
} else if (arg < -13*M_PI/16) {
v -= 13.0/6;
} else if (arg < -11*M_PI/16) {
v -= 11.0/16;
} else if (arg < -9*M_PI/16) {
v -= 9.0/16;
} else if (arg < -7*M_PI/16) {
v -= 7.0/16;
} else if (arg < -5*M_PI/16) {
v -= 5.0/16;
} else if (arg < -3*M_PI/16) {
v -= 3.0/16;
} else if (arg < -M_PI/16) {
v -= 1.0/16;
} else if (arg < M_PI/16) {
v += 1.0/16;
} else if (arg < 3.0*M_PI/16) {
v += 3.0/16;
} else if (arg < 5.0*M_PI/16) {
v += 5.0/16;
} else if (arg < 7.0*M_PI/16) {
v += 7.0/16;
} else if (arg < 9.0*M_PI/16) {
v += 9.0/16;
} else if (arg < 11.0*M_PI/16) {
v += 11.0/16;
} else if (arg < 13.0*M_PI/16) {
v += 13.0/16;
} else if (arg < 15.0*M_PI/16) {
v += 15.0/16;
} else if (arg < M_PI) {
v -= 15.0/16;
}
}
break;
case ProjectionReal:
default:
v = s.m_real / SDR_RX_SCALEF;
@ -91,3 +192,15 @@ Real Projector::run(const Sample& s)
}
}
Real Projector::normalizeAngle(Real angle)
{
while (angle <= -M_PI) {
angle += 2.0*M_PI;
}
while (angle > M_PI) {
angle -= 2.0*M_PI;
}
return angle;
}

5
sdrbase/dsp/projector.h
View File

@ -28,6 +28,10 @@ public:
ProjectionMagDB, //!< Calculate logarithmic (dB) of squared magnitude
ProjectionPhase, //!< Calculate phase
ProjectionDPhase, //!< Calculate phase derivative i.e. instantaneous frequency scaled to sample rate
ProjectionBPSK, //!< Phase comparator BPSK evaluation
ProjectionQPSK, //!< Phase comparator QPSK evaluation
Projection8PSK, //!< Phase comparator 8-PSK evaluation
Projection16PSK, //!< Phase comparator 16-PSK evaluation
nbProjectionTypes //!< Gives the number of projections in the enum
};
@ -42,6 +46,7 @@ public:
Real run(const Sample& s);
private:
static Real normalizeAngle(Real angle);
ProjectionType m_projectionType;
Real m_prevArg;
Real *m_cache;

4
sdrgui/gui/glscopenggui.cpp
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@ -1187,6 +1187,10 @@ void GLScopeNGGUI::fillProjectionCombo(QComboBox* comboBox)
comboBox->addItem("MagdB", Projector::ProjectionMagDB);
comboBox->addItem("Phi", Projector::ProjectionPhase);
comboBox->addItem("dPhi", Projector::ProjectionDPhase);
comboBox->addItem("BPSK", Projector::ProjectionBPSK);
comboBox->addItem("QPSK", Projector::ProjectionQPSK);
comboBox->addItem("8PSK", Projector::Projection8PSK);
comboBox->addItem("16PSK", Projector::Projection16PSK);
}
void GLScopeNGGUI::disableLiveMode(bool disable)