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Synch.

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This commit is contained in:
John Greb 2015-01-22 22:30:55 +00:00
parent 3c9ab44d68
commit d4a9f8e8e3
3 changed files with 37 additions and 21 deletions
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14
plugins/channel/lora/lorabits.h
View File

@ -17,18 +17,8 @@ void LoRaDemod::interleave(short* inout)
}
}
// Same sequence for any size
void LoRaDemod::make_gray()
short LoRaDemod::toGray(short num)
{
short k = 0;
for (short i = 0; i < 1<<8; i++) {
gray[i] = k;
// ungray[k] = i;
short r = (i+1) & ~i;
k ^= r;
}
// for (short i = 0; i < 1<<5; i++)
// printf("%x:%x:%x.\n", i, gray[i], ungray[gray[i]]);
return (num >> 1) ^ num;
}

37
plugins/channel/lora/lorademod.cpp
View File

@ -41,13 +41,13 @@ LoRaDemod::LoRaDemod(SampleSink* sampleSink) :
m_result = 0;
m_count = 0;
m_header = 0;
m_time = 0;
loraFilter = new sfft(LORA_SFFT_LEN);
negaFilter = new sfft(LORA_SFFT_LEN);
mov = new float[4*LORA_SFFT_LEN];
gray = new short[1<<8];
make_gray();
history = new short[256];
}
LoRaDemod::~LoRaDemod()
@ -58,8 +58,8 @@ LoRaDemod::~LoRaDemod()
delete negaFilter;
if (mov)
delete [] mov;
if (gray)
delete [] gray;
if (history)
delete [] history;
}
void LoRaDemod::configure(MessageQueue* messageQueue, Real Bandwidth)
@ -68,10 +68,31 @@ void LoRaDemod::configure(MessageQueue* messageQueue, Real Bandwidth)
cmd->submit(messageQueue, this);
}
short LoRaDemod::synch(short bin)
{
if (bin < 0) {
m_time = 0;
return 0;
}
history[m_time] = bin;
if (m_time > 12)
if (history[m_time] == history[m_time - 6])
if (history[m_time] == history[m_time - 12]) {
m_time = 0;
m_tune = bin;
return 0;
}
m_time++;
m_time &= 255;
if (m_time < 4)
return 0;
return (LORA_SFFT_LEN + bin - m_tune) & (LORA_SFFT_LEN - 1);
}
int LoRaDemod::detect(Complex c, Complex a)
{
int i, result, negresult, movpoint;
short i, result, negresult, movpoint;
float peak, negpeak, tfloat;
float mag[LORA_SFFT_LEN];
float rev[LORA_SFFT_LEN];
@ -101,8 +122,10 @@ int LoRaDemod::detect(Complex c, Complex a)
}
mov[movpoint * LORA_SFFT_LEN + i] = mag[i];
}
if (peak > negpeak) {
m_result = result;
if (peak > negpeak * 4) {
m_result = synch(result);
} else {
synch(-1);
}
return m_result;
}

7
plugins/channel/lora/lorademod.h
View File

@ -45,7 +45,8 @@ public:
private:
int detect(Complex sample, Complex angle);
void interleave(short* inout);
void make_gray();
short synch (short bin);
short toGray(short bin);
class MsgConfigureLoRaDemod : public Message {
MESSAGE_CLASS_DECLARATION
@ -76,11 +77,13 @@ private:
int m_result;
int m_count;
int m_header;
int m_time;
short m_tune;
sfft* loraFilter;
sfft* negaFilter;
float* mov;
short* gray;
short* history;
NCO m_nco;
Interpolator m_interpolator;