M17 mod: implement BERT

modems/m17/M17Demodulator.cpp

@@ -98,7 +98,7 @@ void M17Demodulator::dcd_off()
     if (diagnostic_callback)
     {
         diagnostic_callback(
-            int(dcd_),
+            dcd_,
             dev.error(),
             dev.deviation(),
             dev.offset(),
@@ -482,7 +482,7 @@ void M17Demodulator::operator()(const float input)
 			if (diagnostic_callback)
 			{
 				diagnostic_callback(
-                    int(dcd_),
+                    dcd_,
                     dev.error(),
                     dev.deviation(),
                     dev.offset(),
@@ -570,7 +570,7 @@ void M17Demodulator::operator()(const float input)
 		if (diagnostic_callback)
 		{
 			diagnostic_callback(
-                int(dcd_),
+                dcd_,
                 dev.error(),
                 dev.deviation(),
                 dev.offset(),

modems/m17/M17Modulator.h

@@ -368,6 +368,82 @@ public:
         return punctured;
     }
 
+    static std::array<int8_t, 368> make_bert_frame(PRBS9& prbs)
+    {
+        std::array<uint8_t, 25> data;   // 24.6125 bytes, 197 bits
+
+        // Generate the data.
+        for (size_t i = 0; i != data.size() - 1; ++i)
+        {
+            uint8_t byte = 0;
+
+            for (int i = 0; i != 8; ++i)
+            {
+                byte <<= 1;
+                byte |= prbs.generate();
+            }
+
+            data[i] = byte;
+        }
+
+        uint8_t byte = 0;
+
+        for (int i = 0; i != 5; ++i)
+        {
+            byte <<= 1;
+            byte |= prbs.generate();
+        }
+
+        byte <<= 3;
+        data[24] = byte;
+
+        std::array<uint8_t, 402> encoded;
+        size_t index = 0;
+        uint32_t memory = 0;
+
+        for (size_t i = 0; i != data.size() - 1; ++i)
+        {
+            auto b = data[i];
+
+            for (size_t j = 0; j != 8; ++j)
+            {
+                uint32_t x = (b & 0x80) >> 7;
+                b <<= 1;
+                memory = update_memory<4>(memory, x);
+                encoded[index++] = convolve_bit(031, memory);
+                encoded[index++] = convolve_bit(027, memory);
+            }
+        }
+
+        auto b = data[24];
+
+        for (size_t j = 0; j != 5; ++j)
+        {
+            uint32_t x = (b & 0x80) >> 7;
+            b <<= 1;
+            memory = update_memory<4>(memory, x);
+            encoded[index++] = convolve_bit(031, memory);
+            encoded[index++] = convolve_bit(027, memory);
+        }
+
+        // Flush the encoder.
+        for (size_t i = 0; i != 4; ++i)
+        {
+            memory = update_memory<4>(memory, 0);
+            encoded[index++] = convolve_bit(031, memory);
+            encoded[index++] = convolve_bit(027, memory);
+        }
+
+        std::array<int8_t, 368> punctured;
+        auto size = puncture(encoded, punctured, P2);
+
+        if (size != 368) {
+            std::cerr << "mobilinkd::M17Modulator::make_bert_frame: incorrect size (not 368)" << size;
+        }
+
+        return punctured;
+    }
+
     static void interleave_and_randomize(std::array<int8_t, 368>& punctured)
     {
         M17Randomizer<368> randomizer;

plugins/channeltx/modm17/m17modgui.cpp

@@ -292,6 +292,13 @@ void M17ModGUI::on_packetMode_toggled(bool checked)
     applySettings();
 }
 
+void M17ModGUI::on_bertMode_toggled(bool checked)
+{
+    m_settings.m_m17Mode = checked ? M17ModSettings::M17ModeM17BERT : M17ModSettings::M17ModeNone;
+    displayModes();
+    applySettings();
+}
+
 void M17ModGUI::on_sendPacket_clicked(bool)
 {
     m_m17Mod->sendPacket();
@@ -602,6 +609,19 @@ void M17ModGUI::displayModes()
     {
         ui->packetMode->setChecked(true);
         ui->packetMode->setEnabled(true);
+        ui->bertMode->setChecked(false);
+        ui->tone->setChecked(false);
+        ui->mic->setChecked(false);
+        ui->play->setChecked(false);
+        ui->bertMode->setEnabled(false);
+        ui->tone->setEnabled(false);
+        ui->mic->setEnabled(false);
+        ui->play->setEnabled(false);
+    }
+    if (m_settings.m_m17Mode ==  M17ModSettings::M17Mode::M17ModeM17BERT)
+    {
+        ui->bertMode->setChecked(true);
+        ui->bertMode->setEnabled(true);
         ui->tone->setChecked(false);
         ui->mic->setChecked(false);
         ui->play->setChecked(false);
@@ -614,9 +634,11 @@ void M17ModGUI::displayModes()
         ui->tone->setChecked(true);
         ui->tone->setEnabled(true);
         ui->packetMode->setChecked(false);
+        ui->bertMode->setChecked(false);
         ui->mic->setChecked(false);
         ui->play->setChecked(false);
         ui->packetMode->setEnabled(false);
+        ui->bertMode->setEnabled(true);
         ui->mic->setEnabled(false);
         ui->play->setEnabled(false);
     }
@@ -625,8 +647,10 @@ void M17ModGUI::displayModes()
     {
         ui->tone->setChecked(false);
         ui->packetMode->setChecked(false);
+        ui->bertMode->setChecked(false);
         ui->tone->setEnabled(false);
         ui->packetMode->setEnabled(false);
+        ui->bertMode->setEnabled(true);
 
         if (m_settings.m_audioType == M17ModSettings::AudioType::AudioInput)
         {
@@ -653,10 +677,12 @@ void M17ModGUI::displayModes()
     else if (m_settings.m_m17Mode == M17ModSettings::M17Mode::M17ModeNone)
     {
         ui->packetMode->setChecked(false);
+        ui->bertMode->setChecked(false);
         ui->tone->setChecked(false);
         ui->mic->setChecked(false);
         ui->play->setChecked(false);
         ui->packetMode->setEnabled(true);
+        ui->bertMode->setEnabled(true);
         ui->tone->setEnabled(true);
         ui->mic->setEnabled(true);
         ui->play->setEnabled(true);
@@ -792,6 +818,7 @@ void M17ModGUI::makeUIConnections()
     QObject::connect(ui->feedbackVolume, &QDial::valueChanged, this, &M17ModGUI::on_feedbackVolume_valueChanged);
     QObject::connect(ui->fmAudio, &ButtonSwitch::toggled, this, &M17ModGUI::on_fmAudio_toggled);
     QObject::connect(ui->packetMode, &ButtonSwitch::toggled, this, &M17ModGUI::on_packetMode_toggled);
+    QObject::connect(ui->bertMode, &ButtonSwitch::toggled, this, &M17ModGUI::on_bertMode_toggled);
     QObject::connect(ui->sendPacket, &QPushButton::clicked, this, &M17ModGUI::on_sendPacket_clicked);
     QObject::connect(ui->loopPacket, &ButtonSwitch::toggled, this, &M17ModGUI::on_loopPacket_toggled);
     QObject::connect(ui->loopPacketInterval, &QDial::valueChanged, this, &M17ModGUI::on_loopPacketInterval_valueChanged);

plugins/channeltx/modm17/m17modgui.h

@@ -134,6 +134,7 @@ private slots:
     void on_feedbackVolume_valueChanged(int value);
 
     void on_packetMode_toggled(bool checked);
+    void on_bertMode_toggled(bool checked);
     void on_sendPacket_clicked(bool checked);
     void on_loopPacket_toggled(bool checked);
     void on_loopPacketInterval_valueChanged(int value);

plugins/channeltx/modm17/m17modgui.ui

@@ -858,6 +858,16 @@
         </property>
        </spacer>
       </item>
+      <item>
+       <widget class="ButtonSwitch" name="bertMode">
+        <property name="toolTip">
+         <string>BERT mode</string>
+        </property>
+        <property name="text">
+         <string>BERT</string>
+        </property>
+       </widget>
+      </item>
      </layout>
     </item>
     <item>

plugins/channeltx/modm17/m17modprocessor.cpp

@@ -28,6 +28,9 @@ MESSAGE_CLASS_DEFINITION(M17ModProcessor::MsgSendAPRS, Message)
 MESSAGE_CLASS_DEFINITION(M17ModProcessor::MsgSendAudioFrame, Message)
 MESSAGE_CLASS_DEFINITION(M17ModProcessor::MsgStartAudio, Message)
 MESSAGE_CLASS_DEFINITION(M17ModProcessor::MsgStopAudio, Message)
+MESSAGE_CLASS_DEFINITION(M17ModProcessor::MsgStartBERT, Message)
+MESSAGE_CLASS_DEFINITION(M17ModProcessor::MsgSendBERTFrame, Message)
+MESSAGE_CLASS_DEFINITION(M17ModProcessor::MsgStopBERT, Message)
 
 M17ModProcessor::M17ModProcessor() :
     m_m17Modulator("MYCALL", ""),
@@ -108,6 +111,24 @@ bool M17ModProcessor::handleMessage(const Message& cmd)
         audioStop();
         return true;
     }
+    else if (MsgStartBERT::match(cmd))
+    {
+        qDebug("M17ModProcessor::handleMessage: MsgStartBERT");
+        m_prbs.reset();
+        send_preamble(); // preamble
+        return true;
+    }
+    else if (MsgSendBERTFrame::match(cmd))
+    {
+        processBERTFrame();
+        return true;
+    }
+    else if (MsgStopBERT::match(cmd))
+    {
+        qDebug("M17ModProcessor::handleMessage: MsgStopBERT");
+        send_eot(); // EOT
+        return true;
+    }
 
     return false;
 }
@@ -243,6 +264,13 @@ void M17ModProcessor::processAudioFrame()
     output_baseband(mobilinkd::M17Modulator::STREAM_SYNC_WORD, temp);
 }
 
+void M17ModProcessor::processBERTFrame()
+{
+    std::array<int8_t, 368> temp = mobilinkd::M17Modulator::make_bert_frame(m_prbs);
+    mobilinkd::M17Modulator::interleave_and_randomize(temp);
+    output_baseband(mobilinkd::M17Modulator::BERT_SYNC_WORD, temp);
+}
+
 std::array<uint8_t, 16> M17ModProcessor::encodeAudio(std::array<int16_t, 320*6>& audioFrame)
 {
     std::array<int16_t, 320> audioFrame8k;

plugins/channeltx/modm17/m17modprocessor.h

@@ -183,6 +183,51 @@ public:
         { }
     };
 
+    class MsgStartBERT : public Message {
+        MESSAGE_CLASS_DECLARATION
+
+    public:
+        static MsgStartBERT* create() {
+            return new MsgStartBERT();
+        }
+
+    private:
+
+        MsgStartBERT() :
+            Message()
+        { }
+    };
+
+    class MsgSendBERTFrame : public Message {
+        MESSAGE_CLASS_DECLARATION
+
+    public:
+        static MsgSendBERTFrame* create() {
+            return new MsgSendBERTFrame();
+        }
+
+    private:
+
+        MsgSendBERTFrame() :
+            Message()
+        { }
+    };
+
+    class MsgStopBERT : public Message {
+        MESSAGE_CLASS_DECLARATION
+
+    public:
+        static MsgStopBERT* create() {
+            return new MsgStopBERT();
+        }
+
+    private:
+
+        MsgStopBERT() :
+            Message()
+        { }
+    };
+
     M17ModProcessor();
     ~M17ModProcessor();
 
@@ -203,6 +248,7 @@ private:
     int m_audioFrameIndex;
     uint16_t m_audioFrameNumber;
     struct CODEC2 *m_codec2;
+    mobilinkd::PRBS9 m_prbs;
     bool m_insertPositionToggle;
 
     bool handleMessage(const Message& cmd);
@@ -211,6 +257,7 @@ private:
     void audioStop();
     void processAudioFrame();
     std::array<uint8_t, 16> encodeAudio(std::array<int16_t, 320*6>& audioFrame);
+    void processBERTFrame();
     void test(const QString& sourceCall, const QString& destCall);
     void send_preamble();
     void send_eot();

plugins/channeltx/modm17/m17modsource.cpp

@@ -51,6 +51,7 @@ M17ModSource::M17ModSource() :
     m_audioReadBufferIndex = 0;
     m_m17PullAudio = false;
     m_m17PullCount = 0;
+    m_m17PullBERT = false;
 
 	m_feedbackAudioBuffer.resize(1<<14);
 	m_feedbackAudioBufferFill = 0;
@@ -358,6 +359,22 @@ void M17ModSource::pullM17(Real& sample, bool& carrier)
             m_m17PullCount = 0;
         }
     }
+    else if (m_settings.m_m17Mode == M17ModSettings::M17ModeM17BERT)
+    {
+        if (!m_m17PullBERT)
+        {
+            M17ModProcessor::MsgStartBERT *msg = M17ModProcessor::MsgStartBERT::create();
+            m_processor->getInputMessageQueue()->push(msg);
+            m_m17PullBERT = true;
+        }
+
+        if ((m_processor->getBasebandFifo()->getFill() < 1920) && (m_m17PullCount > 192))
+        {
+            M17ModProcessor::MsgSendBERTFrame *msg = M17ModProcessor::MsgSendBERTFrame::create();
+            m_processor->getInputMessageQueue()->push(msg);
+            m_m17PullCount = 0;
+        }
+    }
     else
     {
         if (m_m17PullAudio)
@@ -366,6 +383,12 @@ void M17ModSource::pullM17(Real& sample, bool& carrier)
             m_processor->getInputMessageQueue()->push(msg);
             m_m17PullAudio = false;
         }
+        else if (m_m17PullBERT)
+        {
+            M17ModProcessor::MsgStopBERT *msg = M17ModProcessor::MsgStopBERT::create();
+            m_processor->getInputMessageQueue()->push(msg);
+            m_m17PullBERT = false;
+        }
     }
 
     // get sample from processor FIFO

plugins/channeltx/modm17/m17modsource.h

@@ -110,6 +110,7 @@ private:
     AudioFifo m_audioFifo;
     bool m_m17PullAudio;
     int m_m17PullCount;
+    bool m_m17PullBERT;
 
     int m_feedbackAudioSampleRate;
     AudioVector m_feedbackAudioBuffer;