fleg
/
OpenRTX
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Cleanup demodulator, improved quantization log 

Unified offset and phase variable to reduce the chance of off-by-ones
between buffers. Improved logging on linux and module17 adding
quantization indices.

TG-81
This commit is contained in:
Niccolò Izzo 2022-05-26 10:05:32 +02:00 committed by Silvano Seva
parent 46c988bdc2
commit 6322cb49a4
3 changed files with 32 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
openrtx/include/protocols/M17/M17Demodulator.h
View File

@ -118,13 +118,13 @@ private:
static constexpr size_t M17_RX_SAMPLE_RATE = 24000;
static constexpr size_t M17_SAMPLES_PER_SYMBOL = M17_RX_SAMPLE_RATE / M17_SYMBOL_RATE;
static constexpr size_t M17_FRAME_SAMPLES = M17_FRAME_SYMBOLS * M17_SAMPLES_PER_SYMBOL;
static constexpr size_t M17_SAMPLE_BUF_SIZE = M17_FRAME_SAMPLES / 2;
static constexpr size_t M17_SYNCWORD_SAMPLES = M17_SAMPLES_PER_SYMBOL * M17_SYNCWORD_SYMBOLS;
static constexpr int8_t SYNC_SWEEP_WIDTH = 10;
static constexpr int8_t SYNC_SWEEP_OFFSET = ceil(SYNC_SWEEP_WIDTH / M17_SAMPLES_PER_SYMBOL);
static constexpr size_t M17_BRIDGE_SIZE = M17_SYNCWORD_SAMPLES + 2 * SYNC_SWEEP_WIDTH;
static constexpr size_t M17_SAMPLES_PER_SYMBOL = M17_RX_SAMPLE_RATE / M17_SYMBOL_RATE;
static constexpr size_t M17_FRAME_SAMPLES = M17_FRAME_SYMBOLS * M17_SAMPLES_PER_SYMBOL;
static constexpr size_t M17_SAMPLE_BUF_SIZE = M17_FRAME_SAMPLES / 2;
static constexpr size_t M17_SYNCWORD_SAMPLES = M17_SAMPLES_PER_SYMBOL * M17_SYNCWORD_SYMBOLS;
static constexpr int8_t SYNC_SWEEP_WIDTH = 10;
static constexpr int8_t SYNC_SWEEP_OFFSET = ceil(SYNC_SWEEP_WIDTH / M17_SAMPLES_PER_SYMBOL);
static constexpr int16_t M17_BRIDGE_SIZE = M17_SYNCWORD_SAMPLES + 2 * SYNC_SWEEP_WIDTH;
static constexpr float CONV_STATS_ALPHA = 0.005f;
static constexpr float CONV_THRESHOLD_FACTOR = 3.40;

43
openrtx/src/protocols/M17/M17Demodulator.cpp
View File

@ -92,6 +92,9 @@ static void *logFunc(void *arg)
{
dumpData = false;
emptyCtr = 0;
#ifdef PLATFORM_LINUX
logRunning = false;
#endif
}
#ifdef PLATFORM_LINUX
@ -103,7 +106,7 @@ static void *logFunc(void *arg)
entry.qnt_pos_avg,
entry.qnt_neg_avg,
entry.symbol,
entry.frame_index
entry.frame_index,
entry.flags);
fflush(csv_log);
#else
@ -114,6 +117,7 @@ static void *logFunc(void *arg)
#ifdef PLATFORM_LINUX
fclose(csv_log);
exit(-1);
#endif
return NULL;
@ -217,6 +221,9 @@ void M17Demodulator::startBasebandSampling()
void M17Demodulator::stopBasebandSampling()
{
inputStream_stop(basebandId);
phase = 0;
syncDetected = false;
locked = false;
}
void M17Demodulator::resetCorrelationStats()
@ -320,7 +327,7 @@ sync_t M17Demodulator::nextFrameSync(int32_t offset)
log.qnt_neg_avg = 0.0;
log.symbol = 0;
log.frame_index = 0;
log.flags = 1;
log.flags = 0;//1;
pushLog(log);
#endif
@ -397,7 +404,7 @@ int32_t M17Demodulator::syncwordSweep(int32_t offset)
log.qnt_neg_avg = 0.0;
log.symbol = 0;
log.frame_index = 0;
log.flags = 2;
log.flags = 0;//2;
pushLog(log);
#endif
@ -414,7 +421,7 @@ int32_t M17Demodulator::syncwordSweep(int32_t offset)
bool M17Demodulator::update()
{
sync_t syncword = { 0, false };
int32_t offset = syncDetected ? 0 : -(int32_t) M17_BRIDGE_SIZE;
phase = (syncDetected) ? phase % M17_SAMPLES_PER_SYMBOL : -M17_BRIDGE_SIZE;
uint16_t decoded_syms = 0;
// Read samples from the ADC
@ -439,12 +446,11 @@ bool M17Demodulator::update()
// If we are not demodulating a syncword, search for one
if (!syncDetected)
{
syncword = nextFrameSync(offset);
syncword = nextFrameSync(phase);
if (syncword.index != -1) // Valid syncword found
{
syncDetected = true;
offset = syncword.index + 1;
phase = 0;
phase = syncword.index + 1;
frame_index = 0;
decoded_syms = 0;
}
@ -453,9 +459,8 @@ bool M17Demodulator::update()
else
{
// Slice the input buffer to extract a frame and quantize
int32_t symbol_index = offset
+ phase
+ (M17_SAMPLES_PER_SYMBOL * decoded_syms);
int32_t symbol_index = phase
+ (M17_SAMPLES_PER_SYMBOL * decoded_syms);
if (symbol_index >= static_cast<int32_t>(baseband.len))
break;
// Update quantization stats only on syncwords
@ -472,14 +477,15 @@ bool M17Demodulator::update()
{
log_entry_t log;
log.sample = baseband.data[symbol_index + i];
log.conv = 0;
log.conv = phase;
log.conv_th = 0.0;
log.sample_index = symbol_index + i;
log.qnt_pos_avg = qnt_pos_avg / 1.5f;
log.qnt_neg_avg = qnt_neg_avg / 1.5f;
log.symbol = symbol;
log.frame_index = frame_index;
log.flags = 3;
log.flags = 0;
if(i == 0) log.flags = 1;
pushLog(log);
}
@ -540,7 +546,7 @@ bool M17Demodulator::update()
{
// Find index (possibly negative) of the syncword
int32_t expected_sync =
offset + phase +
phase +
M17_SAMPLES_PER_SYMBOL * decoded_syms -
M17_SYNCWORD_SAMPLES -
SYNC_SWEEP_OFFSET * M17_SAMPLES_PER_SYMBOL;
@ -557,18 +563,15 @@ bool M17Demodulator::update()
}
}
}
// We are at the end of the buffer
if (syncDetected)
{
// Compute phase of next buffer
phase = (static_cast<int32_t> (phase) + offset + baseband.len) % M17_SAMPLES_PER_SYMBOL;
}
// Copy last N samples to bridge buffer
memcpy(basebandBridge,
baseband.data + (baseband.len - M17_BRIDGE_SIZE),
sizeof(int16_t) * M17_BRIDGE_SIZE);
}
#ifdef PLATFORM_LINUX
if (baseband.data == NULL)
dumpData = true;
#endif
return newFrame;
}

3
platform/drivers/audio/inputStream_linux.c
View File

@ -77,7 +77,8 @@ dataBlock_t inputStream_getData(streamId id)
if (read_items != block.len)
{
exit(-1);
block.data = NULL;
return block;
}
return block;