SSB demod: improve AGC threshold handling

plugins/channelrx/demodssb/ssbdemod.cpp

@@ -302,7 +302,7 @@ bool SSBDemod::handleMessage(const Message& cmd)
 		DSBFilter->create_dsb_filter((2.0f * m_Bandwidth) / (float) m_audioSampleRate);
 
 		m_volume = cfg.getVolume();
-		m_volume *= m_volume * 0.1;
+		m_volume *= 2.0;
 
 		m_spanLog2 = cfg.getSpanLog2();
 		m_audioBinaual = cfg.getAudioBinaural();

plugins/channelrx/demodssb/ssbdemodgui.cpp

@@ -129,9 +129,17 @@ bool SSBDemodGUI::deserialize(const QByteArray& data)
 		d.readBool(11, &booltmp, false);
 		ui->agc->setChecked(booltmp);
 		d.readS32(12, &tmp, 7);
-		ui->agcTimeText->setText(QString("%1").arg((1<<tmp), 0, 'f', 0));
+		ui->agcTimeLog2->setValue(tmp);
+	    QString s = QString::number((1<<tmp), 'f', 0);
+	    ui->agcTimeText->setText(s);
         d.readS32(13, &tmp, -20);
-        ui->agcPowerThresholdText->setText(QString("%1").arg(tmp, 0, 'f', 0));
+        ui->agcPowerThreshold->setValue(tmp);
+        s = QString::number(tmp, 'f', 0);
+        ui->agcPowerThresholdText->setText(s);
+        d.readS32(14, &tmp, 5);
+        ui->agcThresholdGate->setValue(tmp);
+        s = QString::number(tmp*10, 'f', 0);
+        ui->agcThresholdGateText->setText(s);
 
 		blockApplySettings(false);
 	    m_channelMarker.blockSignals(false);
@@ -275,20 +283,29 @@ void SSBDemodGUI::on_volume_valueChanged(int value)
 	applySettings();
 }
 
-void SSBDemodGUI::on_agc_stateChanged(int state)
+void SSBDemodGUI::on_agc_stateChanged(int state __attribute((__unused__)))
 {
     applySettings();
 }
 
 void SSBDemodGUI::on_agcTimeLog2_valueChanged(int value)
 {
-    ui->agcTimeText->setText(QString("%1").arg((1<<value), 0, 'f', 0));
+    QString s = QString::number((1<<value), 'f', 0);
+    ui->agcTimeText->setText(s);
     applySettings();
 }
 
 void SSBDemodGUI::on_agcPowerThreshold_valueChanged(int value)
 {
-    ui->agcPowerThresholdText->setText(QString("%1").arg(value, 0, 'f', 0));
+    QString s = QString::number(value, 'f', 0);
+    ui->agcPowerThresholdText->setText(s);
+    applySettings();
+}
+
+void SSBDemodGUI::on_agcThresholdGate_valueChanged(int value)
+{
+    QString s = QString::number(value * 10, 'f', 0);
+    ui->agcThresholdGateText->setText(s);
     applySettings();
 }
 

plugins/channelrx/demodssb/ssbdemodgui.h

@@ -51,6 +51,7 @@ private slots:
 	void on_agc_stateChanged(int state);
 	void on_agcTimeLog2_valueChanged(int value);
     void on_agcPowerThreshold_valueChanged(int value);
+    void on_agcThresholdGate_valueChanged(int value);
 	void on_audioMute_toggled(bool checked);
 	void on_spanLog2_valueChanged(int value);
 	void onWidgetRolled(QWidget* widget, bool rollDown);

plugins/channelrx/demodssb/ssbdemodgui.ui

@@ -6,7 +6,7 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>370</width>
+    <width>435</width>
     <height>160</height>
    </rect>
   </property>
@@ -36,7 +36,7 @@
     <rect>
      <x>0</x>
      <y>0</y>
-     <width>360</width>
+     <width>421</width>
      <height>151</height>
     </rect>
    </property>
@@ -479,8 +479,11 @@
         <property name="toolTip">
          <string>AGC time constant (ms in log2 steps)</string>
         </property>
+        <property name="minimum">
+         <number>4</number>
+        </property>
         <property name="maximum">
-         <number>10</number>
+         <number>11</number>
         </property>
         <property name="pageStep">
          <number>1</number>
@@ -494,7 +497,7 @@
        <widget class="QLabel" name="agcTimeText">
         <property name="minimumSize">
          <size>
-          <width>30</width>
+          <width>35</width>
           <height>0</height>
          </size>
         </property>
@@ -553,6 +556,47 @@
         </property>
        </widget>
       </item>
+      <item>
+       <widget class="QDial" name="agcThresholdGate">
+        <property name="maximumSize">
+         <size>
+          <width>24</width>
+          <height>24</height>
+         </size>
+        </property>
+        <property name="toolTip">
+         <string>Set threshiold gate (ms)</string>
+        </property>
+        <property name="maximum">
+         <number>50</number>
+        </property>
+        <property name="pageStep">
+         <number>1</number>
+        </property>
+        <property name="value">
+         <number>5</number>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <widget class="QLabel" name="agcThresholdGateText">
+        <property name="minimumSize">
+         <size>
+          <width>24</width>
+          <height>0</height>
+         </size>
+        </property>
+        <property name="toolTip">
+         <string>Threshiold gate (ms)</string>
+        </property>
+        <property name="text">
+         <string>000</string>
+        </property>
+        <property name="alignment">
+         <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
+        </property>
+       </widget>
+      </item>
       <item>
        <spacer name="horizontalSpacer">
         <property name="orientation">

sdrbase/dsp/agc.cpp

@@ -6,6 +6,7 @@
  */
 
 #include "dsp/agc.h"
+#include "util/smootherstep.h"
 
 
 AGC::AGC(int historySize, Real R) :
@@ -46,7 +47,9 @@ MagSquaredAGC::MagSquaredAGC(int historySize, double R, double threshold) :
 	AGC(historySize, R),
 	m_magsq(0.0),
 	m_threshold(threshold),
-	m_thresholdCount(0)
+	m_gate(0),
+	m_stepCounter(0),
+	m_gateCounter(0)
 {}
 
 MagSquaredAGC::~MagSquaredAGC()
@@ -68,16 +71,39 @@ double MagSquaredAGC::feedAndGetValue(const Complex& ci)
 
     if (m_magsq > m_threshold)
     {
-        m_thresholdCount = 0;
+        if (m_gateCounter < m_gate)
+        {
+            m_gateCounter++;
         }
         else
         {
-        if (m_thresholdCount < m_moving_average.historySize()) {
+            m_count = 0;
-            m_thresholdCount++;
         }
     }
+    else
+    {
+        if (m_count < m_moving_average.historySize()) {
+            m_count++;
+        }
 
-    return (m_thresholdCount <  m_moving_average.historySize()) ? m_u0 : 0.0;
+        m_gateCounter = 0;
+    }
+
+    if (m_count <  m_moving_average.historySize())
+    {
+        if (m_stepCounter < 2400) {
+            m_stepCounter++;
+        }
+
+        return m_u0 * StepFunctions::smootherstep(m_stepCounter/2400.0);
+    }
+    else
+    {
+        m_stepCounter = 0;
+        return 0.0;
+    }
+
+    //return (m_count <  m_moving_average.historySize()) ? m_u0 : 0.0;
 }
 
 //MagAGC::MagAGC() :
@@ -89,7 +115,9 @@ MagAGC::MagAGC(int historySize, double R, double threshold) :
 	AGC(historySize, R),
 	m_magsq(0.0),
 	m_threshold(threshold),
-	m_thresholdCount(0)
+	m_gate(0),
+	m_stepCounter(0),
+	m_gateCounter(0)
 {}
 
 MagAGC::~MagAGC()
@@ -111,16 +139,39 @@ double MagAGC::feedAndGetValue(const Complex& ci)
 
     if (m_magsq > m_threshold)
     {
-        m_thresholdCount = 0;
+        if (m_gateCounter < m_gate)
+        {
+            m_gateCounter++;
         }
         else
         {
-        if (m_thresholdCount < m_moving_average.historySize()) {
+            m_count = 0;
-            m_thresholdCount++;
         }
     }
+    else
+    {
+        if (m_count < m_moving_average.historySize()) {
+            m_count++;
+        }
 
-    return (m_thresholdCount <  m_moving_average.historySize()) ? m_u0 : 0.0;
+        m_gateCounter = 0;
+    }
+
+    if (m_count <  m_moving_average.historySize())
+    {
+        if (m_stepCounter < 480) {
+            m_stepCounter++;
+        }
+
+        return m_u0 * StepFunctions::smootherstep(m_stepCounter/480.0);
+    }
+    else
+    {
+        m_stepCounter = 0;
+        return 0.0;
+    }
+
+    //return (m_count <  m_moving_average.historySize()) ? m_u0 : 0.0;
 }
 
 //AlphaAGC::AlphaAGC() :

sdrbase/dsp/agc.h

@@ -38,10 +38,13 @@ public:
 	double feedAndGetValue(const Complex& ci);
 	double getMagSq() const { return m_magsq; }
 	void setThreshold(double threshold) { m_threshold = threshold; }
+	void setGate(int gate) { m_gate = gate; }
 private:
 	double m_magsq;
 	double m_threshold; //!< squelch on magsq average with transition from +3dB
-    int m_thresholdCount;
+    int m_gate;
+    int m_stepCounter;
+    int m_gateCounter;
 };
 
 class MagAGC : public AGC
@@ -53,10 +56,13 @@ public:
     double feedAndGetValue(const Complex& ci);
 	Real getMagSq() const { return m_magsq; }
     void setThreshold(double threshold) { m_threshold = threshold; }
+    void setGate(int gate) { m_gate = gate; }
 private:
 	double m_magsq;
     double m_threshold; //!< squelch on magsq average
-    int m_thresholdCount;
+    int m_gate;
+    int m_stepCounter;
+    int m_gateCounter;
 };
 
 class AlphaAGC : public AGC

sdrbase/util/smootherstep.h

@@ -0,0 +1,30 @@
+/*
+ * smootherstep.h
+ *
+ *  Created on: Jul 25, 2017
+ *      Author: f4exb
+ */
+
+#ifndef SDRBASE_UTIL_SMOOTHERSTEP_H_
+#define SDRBASE_UTIL_SMOOTHERSTEP_H_
+
+class StepFunctions
+{
+public:
+    static float smootherstep(float x)
+    {
+        if (x == 1.0f) {
+            return 1.0f;
+        } else if (x == 0.0f) {
+            return 0.0f;
+        }
+
+        double x3 = x * x * x;
+        double x4 = x * x3;
+        double x5 = x * x4;
+
+        return (float) (6.0*x5 - 15.0*x4 + 10.0*x3);
+    }
+};
+
+#endif /* SDRBASE_UTIL_SMOOTHERSTEP_H_ */