31 kHz.

plugins/channel/lora/lorabits.h

@@ -1,10 +1,15 @@
 /*
  Interleaving is "easiest" if the same number of bits is used per symbol as for FEC
  Chosen mode "spreading 8, low rate" has 6 bits per symbol, so use 4:6 FEC
+
+ More spreading needs higher frequency resolution and longer time on air, increasing drift errors.
+ Want higher bandwidth when using more spreading, which needs more CPU.
+
+ Six bit Hamming can only correct drift errors. Want 7 or 8 bit FEC for QRM
 */
 
 // Needs adjusting for different sizes
-void LoRaDemod::interleave(char* inout, int size)
+void LoRaDemod::interleave6(char* inout, int size)
 {
 	int i, j;
 	char in[6 * 2];
@@ -32,7 +37,7 @@ short LoRaDemod::toGray(short num)
 }
 
 // ignore FEC, try to extract raw bits
-void LoRaDemod::hamming(char* c, int size)
+void LoRaDemod::hamming6(char* c, int size)
 {
 	int i;
 
@@ -53,7 +58,7 @@ void LoRaDemod::hamming(char* c, int size)
 }
 
 // data whitening (6 bit)
-void LoRaDemod::prng(char* inout, int size)
+void LoRaDemod::prng6(char* inout, int size)
 {
 	const char otp[] = {
 	"5^ZSm0=cOGMgUB=bNcb<@a^T;_f=6DEB]2ImPIKg:j]RlYT4YZ<`9hZ\\PPb;@8X8i]Zmc_6B52\\8oUPHIcBOc>dY?d9[n5Lg]b]R8hR<0`T008h9c9QJm[c?a:lQEGa;nU=b_UbTW3=W5Aa<9i;F;ondS[LBA;[4S9]kkh]Vc2j>kX"

plugins/channel/lora/lorademod.cpp

@@ -85,9 +85,9 @@ void LoRaDemod::dumpRaw()
 		text[j] = toGray(bin >> 1);
 	}
 
-	prng(text, max);
-	interleave(text, max);
-	hamming(text, max);
+	prng6(text, max);
+	interleave6(text, max);
+	hamming6(text, max);
 
 	for ( j=0; j < max / 2; j++) {
 		text[j] = (text[j * 2 + 2] << 4) | (0xf & text[j * 2 + 1]);
@@ -167,7 +167,7 @@ int LoRaDemod::detect(Complex c, Complex a)
 	q = (result + 1) & (LORA_SFFT_LEN -1);
 	finetune[15 & m_time] = (mag[p] > mag[q]) ? -1 : 1;
 
-	if (peak < negpeak * 4)
+	if (peak < negpeak * LORA_SQUELCH)
 		result = -1;
 	result = synch(result);
 	if (result >= 0)

plugins/channel/lora/lorademod.h

@@ -29,6 +29,7 @@
 #define SAMPLEBITS (DATA_BITS + 2)
 #define SPREADFACTOR (1 << SAMPLEBITS)
 #define LORA_SFFT_LEN (SPREADFACTOR / 2)
+#define LORA_SQUELCH (3)
 
 class LoRaDemod : public SampleSink {
 public:
@@ -44,12 +45,12 @@ public:
 
 private:
 	int  detect(Complex sample, Complex angle);
-	void interleave(char* inout, int size);
 	void dumpRaw(void);
 	short synch (short bin);
 	short toGray(short bin);
-	void hamming(char* inout, int size);
-	void prng(char* inout, int size);
+	void interleave6(char* inout, int size);
+	void hamming6(char* inout, int size);
+	void prng6(char* inout, int size);
 
 	class MsgConfigureLoRaDemod : public Message {
 		MESSAGE_CLASS_DECLARATION

plugins/channel/lora/lorademodgui.cpp

@@ -86,7 +86,7 @@ void LoRaDemodGUI::viewChanged()
 
 void LoRaDemodGUI::on_BW_valueChanged(int value)
 {
-	const int loraBW[] = {7813, 15625, 10417, 20833};
+	const int loraBW[] = {7813, 15625, 31250, 62500};
 	int thisBW = loraBW[value];
 	ui->BWText->setText(QString("%1 Hz").arg(thisBW));
 	m_channelMarker->setBandwidth(thisBW);
@@ -165,7 +165,7 @@ LoRaDemodGUI::~LoRaDemodGUI()
 
 void LoRaDemodGUI::applySettings()
 {
-	const int  loraBW[] = {7813, 15625, 10417, 20833};
+	const int  loraBW[] = {7813, 15625, 31250, 62500};
 	int thisBW = loraBW[ui->BW->value()];
 	m_channelizer->configure(m_threadedSampleSink->getMessageQueue(),
 		thisBW,

plugins/channel/lora/lorademodgui.ui

@@ -52,7 +52,7 @@
        <number>0</number>
       </property>
       <property name="maximum">
-       <number>1</number>
+       <number>2</number>
       </property>
       <property name="pageStep">
        <number>1</number>