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First compileable version, but untested.

dstar_correlator
Jonathan Naylor 2017-07-06 20:28:20 +01:00
parent c22f360ed1
commit 90797696dd
4 changed files with 95 additions and 91 deletions
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14
DStarDefines.h
View File

@ -24,21 +24,23 @@ const unsigned int DSTAR_RADIO_SYMBOL_LENGTH = 5U; // At 24 kHz sample rate
const unsigned int DSTAR_HEADER_LENGTH_BYTES = 41U;
const unsigned int DSTAR_FEC_SECTION_LENGTH_BYTES = 83U;
const unsigned int DSTAR_FEC_SECTION_LENGTH_BITS = 660U;
const unsigned int DSTAR_FEC_SECTION_LENGTH_SAMPLES = DSTAR_FEC_SECTION_LENGTH_BITS * DSTAR_RADIO_SYMBOL_LENGTH;
const unsigned int DSTAR_FEC_SECTION_LENGTH_SYMBOLS = 660U;
const unsigned int DSTAR_FEC_SECTION_LENGTH_SAMPLES = DSTAR_FEC_SECTION_LENGTH_SYMBOLS * DSTAR_RADIO_SYMBOL_LENGTH;
const unsigned int DSTAR_DATA_LENGTH_BYTES = 12U;
const unsigned int DSTAR_DATA_LENGTH_BITS = DSTAR_DATA_LENGTH_BYTES * 8U;
const unsigned int DSTAR_DATA_LENGTH_SAMPLES = DSTAR_DATA_LENGTH_BITS * DSTAR_RADIO_SYMBOL_LENGTH;
const unsigned int DSTAR_DATA_LENGTH_SYMBOLS = DSTAR_DATA_LENGTH_BYTES * 8U;
const unsigned int DSTAR_DATA_LENGTH_SAMPLES = DSTAR_DATA_LENGTH_SYMBOLS * DSTAR_RADIO_SYMBOL_LENGTH;
const unsigned int DSTAR_EOT_LENGTH_BYTES = 6U;
const unsigned int DSTAR_EOT_LENGTH_BITS = DSTAR_EOT_LENGTH_BYTES * 8U;
const unsigned int DSTAR_END_SYNC_LENGTH_BYTES = 6U;
const unsigned int DSTAR_END_SYNC_LENGTH_BITS = DSTAR_END_SYNC_LENGTH_BYTES * 8U;
const unsigned int DSTAR_FRAME_SYNC_LENGTH_BYTES = 3U;
const unsigned int DSTAR_FRAME_SYNC_LENGTH_SYMBOLS = DSTAR_FRAME_SYNC_LENGTH_BYTES * 8U;
const unsigned int DSTAR_FRAME_SYNC_LENGTH_SAMPLES = DSTAR_FRAME_SYNC_LENGTH_SYMBOLS * DSTAR_RADIO_SYMBOL_LENGTH;
const unsigned int DSTAR_DATA_SYNC_LENGTH_BYTES = 3U;
const unsigned int DSTAR_DATA_SYNC_LENGTH_SYMBOLS = DSTAR_DATA_SYNC_LENGTH_BYTES * 8U;
const unsigned int DSTAR_DATA_SYNC_LENGTH_SAMPLES = DSTAR_DATA_SYNC_LENGTH_SYMBOLS * DSTAR_RADIO_SYMBOL_LENGTH;
const uint8_t DSTAR_DATA_SYNC_BYTES[] = {0x9E, 0x8D, 0x32, 0x88, 0x26, 0x1A, 0x3F, 0x61, 0xE8, 0x55, 0x2D, 0x16};

148
DStarRX.cpp
View File

@ -22,19 +22,15 @@
#include "DStarRX.h"
#include "Utils.h"
const unsigned int MAX_SYNC_BITS = 50U * DSTAR_DATA_LENGTH_BITS;
const unsigned int SYNC_POS = 21U * DSTAR_DATA_LENGTH_BITS;
const unsigned int SYNC_SCAN_START = SYNC_POS - 2U;
const unsigned int SYNC_SCAN_END = SYNC_POS + 2U;
const unsigned int MAX_FRAMES = 75U;
// Generated using [b, a] = butter(1, 0.001) in MATLAB
static q31_t DC_FILTER[] = {3367972, 0, 3367972, 0, 2140747704, 0}; // {b0, 0, b1, b2, -a1, -a2}
const uint32_t DC_FILTER_STAGES = 1U; // One Biquad stage
const uint8_t MAX_FRAME_SYNC_SYMBOL_ERRS = 2U;
const uint8_t MAX_DATA_SYNC_SYMBOL_ERRS = 2U;
const uint8_t MAX_END_SYNC_SYMBOL_ERRS = 3U;
const uint8_t MAX_FRAME_SYNC_BIT_ERRS = 2U;
const uint8_t MAX_DATA_SYNC_BIT_ERRS = 2U;
const uint8_t MAX_END_SYNC_BIT_ERRS = 3U;
const uint8_t BIT_MASK_TABLE0[] = {0x7FU, 0xBFU, 0xDFU, 0xEFU, 0xF7U, 0xFBU, 0xFDU, 0xFEU};
const uint8_t BIT_MASK_TABLE1[] = {0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U, 0x02U, 0x01U};
@ -239,13 +235,11 @@ m_bitPtr(0U),
m_headerPtr(0U),
m_dataPtr(0U),
m_startPtr(NOENDPTR),
m_endPtr(NOENDPTR),
m_syncPtr(NOENDPTR),
m_minSyncPtr(NOENDPTR),
m_maxSyncPtr(NOENDPTR),
m_maxFrameCorr(0),
m_maxDataCorr(0),
m_lostCount(0U),
m_frameCount(0U),
m_countdown(0U),
m_mar(0U),
m_pathMetric(),
@ -276,11 +270,9 @@ void CDStarRX::reset()
m_maxFrameCorr = 0;
m_maxDataCorr = 0;
m_startPtr = NOENDPTR;
m_endPtr = NOENDPTR;
m_syncPtr = NOENDPTR;
m_minSyncPtr = NOENDPTR;
m_maxSyncPtr = NOENDPTR;
m_lostCount = 0U;
m_frameCount = 0U;
m_countdown = 0U;
m_rssiAccum = 0U;
m_rssiCount = 0U;
@ -343,8 +335,8 @@ void CDStarRX::processNone(q15_t sample)
m_countdown = 5U;
m_headerBuffer[0U] = sample;
m_headerPtr = 1U;
m_headerBuffer[m_headerPtr] = sample;
m_headerPtr++;
m_rssiAccum = 0U;
m_rssiCount = 0U;
@ -362,17 +354,6 @@ void CDStarRX::processNone(q15_t sample)
io.setDecode(true);
io.setADCDetection(true);
// Suppress RSSI on the dummy sync message
m_rssiAccum = 0U;
m_rssiCount = 0U;
::memcpy(m_rxBuffer, DSTAR_DATA_SYNC_BYTES, DSTAR_DATA_LENGTH_BYTES);
writeRSSIData(m_rxBuffer);
::memset(m_rxBuffer, 0x00U, DSTAR_DATA_LENGTH_BYTES + 2U);
m_rxBufferBits = 0U;
m_dataBits = 0U;
m_rxState = DSRXS_DATA;
}
}
@ -389,31 +370,47 @@ void CDStarRX::processHeader(q15_t sample)
// A full FEC header
if (m_headerPtr == DSTAR_FEC_SECTION_LENGTH_SAMPLES) {
// Process the scrambling, interleaving and FEC, then return if the chcksum was correct
uint8_t buffer[DSTAR_FEC_SECTION_LENGTH_BYTES];
samplesToBits(m_headerBuffer, m_startPtr, DSTAR_FEC_SECTION_LENGTH_SYMBOLS, buffer, DSTAR_FEC_SECTION_LENGTH_SAMPLES);
samplesToBits(m_headerBuffer, 0U, DSTAR_FEC_SECTION_LENGTH_SYMBOLS, buffer, DSTAR_FEC_SECTION_LENGTH_SAMPLES);
// Process the scrambling, interleaving and FEC, then return true if the chcksum was correct
uint8_t header[DSTAR_HEADER_LENGTH_BYTES];
bool ok = rxHeader(buffer, header);
if (ok) {
io.setDecode(true);
io.setADCDetection(true);
writeRSSIHeader(header);
m_rxState = DSRXS_DATA;
m_dataBits = SYNC_POS - DSTAR_DATA_LENGTH_BITS + 1U;
} else {
if (!ok) {
// The checksum failed, return to looking for syncs
m_rxState = DSRXS_NONE;
m_maxFrameCorr = 0;
m_maxDataCorr = 0;
}
}
// Reday to start the first data section
if (m_headerPtr == (DSTAR_FEC_SECTION_LENGTH_SAMPLES + DSTAR_RADIO_SYMBOL_LENGTH)) {
m_frameCount = 0U;
m_startPtr = m_dataPtr;
m_maxSyncPtr = m_dataPtr + DSTAR_DATA_LENGTH_SAMPLES - DSTAR_DATA_SYNC_LENGTH_SAMPLES + 2U;
if (m_maxSyncPtr >= DSTAR_DATA_LENGTH_SAMPLES)
m_maxSyncPtr -= DSTAR_DATA_LENGTH_SAMPLES;
m_minSyncPtr = m_dataPtr + DSTAR_DATA_LENGTH_SAMPLES - DSTAR_DATA_SYNC_LENGTH_SAMPLES - 2U;
if (m_minSyncPtr >= DSTAR_DATA_LENGTH_SAMPLES)
m_minSyncPtr -= DSTAR_DATA_LENGTH_SAMPLES;
}
// Reday to start the first data section
if (m_headerPtr == (DSTAR_FEC_SECTION_LENGTH_SAMPLES + DSTAR_RADIO_SYMBOL_LENGTH + DSTAR_RADIO_SYMBOL_LENGTH)) {
m_rxState = DSRXS_DATA;
m_maxFrameCorr = 0;
m_maxDataCorr = 0;
}
}
void CDStarRX::processData()
{
// Fuzzy matching of the end frame sequences
if (countBits32((m_bitBuffer[m_bitPtr] & DSTAR_END_SYNC_MASK) ^ DSTAR_END_SYNC_DATA) <= MAX_END_SYNC_SYMBOL_ERRS) {
if (countBits32((m_bitBuffer[m_bitPtr] & DSTAR_END_SYNC_MASK) ^ DSTAR_END_SYNC_DATA) <= MAX_END_SYNC_BIT_ERRS) {
DEBUG1("DStarRX: Found end sync in Data");
io.setDecode(false);
@ -421,16 +418,26 @@ void CDStarRX::processData()
serial.writeDStarEOT();
m_maxFrameCorr = 0;
m_maxDataCorr = 0;
m_rxState = DSRXS_NONE;
return;
}
// Fuzzy matching of the data sync bit sequence
// Check to see if the sync is arriving late
if ((m_frameCount % 21U) == 0U) {
if (m_minSyncPtr < m_maxSyncPtr) {
if (m_dataPtr >= m_minSyncPtr && m_dataPtr <= m_maxSyncPtr)
correlateDataSync();
} else {
if (m_dataPtr >= m_minSyncPtr || m_dataPtr <= m_maxSyncPtr)
correlateDataSync();
}
}
// We've not seen a data sync for too long, signal RXLOST and change to RX_NONE
if (m_dataBits >= MAX_SYNC_BITS) {
if (m_frameCount >= MAX_FRAMES) {
DEBUG1("DStarRX: data sync timed out, lost lock");
io.setDecode(false);
@ -438,15 +445,19 @@ void CDStarRX::processData()
serial.writeDStarLost();
m_maxFrameCorr = 0;
m_maxDataCorr = 0;
m_rxState = DSRXS_NONE;
return;
}
// Send a data frame to the host if the required number of bits have been received
if (m_dataPtr == m_endPtr) {
if (m_dataPtr == m_maxSyncPtr) {
uint8_t buffer[DSTAR_DATA_LENGTH_BYTES + 2U];
samplesToBits(m_dataBuffer, m_startPtr, DSTAR_DATA_LENGTH_SYMBOLS, buffer, DSTAR_DATA_LENGTH_SAMPLES);
if (syncSeen) {
if (m_frameCount == 0U) {
buffer[9U] = DSTAR_DATA_SYNC_BYTES[9U];
buffer[10U] = DSTAR_DATA_SYNC_BYTES[10U];
buffer[11U] = DSTAR_DATA_SYNC_BYTES[11U];
@ -454,6 +465,11 @@ void CDStarRX::processData()
} else {
serial.writeDStarData(buffer, DSTAR_DATA_LENGTH_BYTES);
}
m_frameCount++;
m_maxFrameCorr = 0;
m_maxDataCorr = 0;
}
}
@ -501,8 +517,8 @@ void CDStarRX::writeRSSIData(unsigned char* data)
bool CDStarRX::correlateFrameSync()
{
if (countBits32((m_bitBuffer[m_bitPtr] & DSTAR_FRAME_SYNC_MASK) ^ DSTAR_FRAME_SYNC_DATA) <= MAX_FRAME_SYNC_SYMBOLS_ERRS) {
uint16_t ptr = m_dataPtr + DSTAR_FRAME_LENGTH_SAMPLES - DSTAR_SYNC_LENGTH_SAMPLES + DSTAR_RADIO_SYMBOL_LENGTH;
if (countBits32((m_bitBuffer[m_bitPtr] & DSTAR_FRAME_SYNC_MASK) ^ DSTAR_FRAME_SYNC_DATA) <= MAX_FRAME_SYNC_BIT_ERRS) {
uint16_t ptr = m_dataPtr + DSTAR_DATA_LENGTH_SAMPLES - DSTAR_FRAME_SYNC_LENGTH_SAMPLES + DSTAR_RADIO_SYMBOL_LENGTH;
if (ptr >= DSTAR_DATA_LENGTH_SAMPLES)
ptr -= DSTAR_DATA_LENGTH_SAMPLES;
@ -522,21 +538,8 @@ bool CDStarRX::correlateFrameSync()
}
if (corr > m_maxFrameCorr) {
uint16_t startPtr = m_dataPtr + DSTAR_FRAME_LENGTH_SAMPLES - DSTAR_SYNC_LENGTH_SAMPLES + DSTAR_RADIO_SYMBOL_LENGTH;
if (startPtr >= DSTAR_FRAME_LENGTH_SAMPLES)
startPtr -= DSTAR_FRAME_LENGTH_SAMPLES;
m_maxFrameCorr = corr;
m_lostCount = MAX_SYNC_FRAMES;
m_syncPtr = m_dataPtr;
m_headerPtr = 0U;
m_startPtr = startPtr;
m_endPtr = m_dataPtr + DSTAR_FRAME_LENGTH_SAMPLES - DSTAR_SYNC_LENGTH_SAMPLES - 1U;
if (m_endPtr >= DSTAR_FRAME_LENGTH_SAMPLES)
m_endPtr -= DSTAR_FRAME_LENGTH_SAMPLES;
return true;
}
}
@ -546,8 +549,8 @@ bool CDStarRX::correlateFrameSync()
bool CDStarRX::correlateDataSync()
{
if (countBits32((m_bitBuffer[m_bitPtr] & DSTAR_DATA_SYNC_MASK) ^ DSTAR_DATA_SYNC_DATA) <= MAX_DATA_SYNC_SYMBOLS_ERRS) {
uint16_t ptr = m_dataPtr + DSTAR_FRAME_LENGTH_SAMPLES - DSTAR_SYNC_LENGTH_SAMPLES + DSTAR_RADIO_SYMBOL_LENGTH;
if (countBits32((m_bitBuffer[m_bitPtr] & DSTAR_DATA_SYNC_MASK) ^ DSTAR_DATA_SYNC_DATA) <= MAX_DATA_SYNC_BIT_ERRS) {
uint16_t ptr = m_dataPtr + DSTAR_DATA_LENGTH_SAMPLES - DSTAR_DATA_SYNC_LENGTH_SAMPLES + DSTAR_RADIO_SYMBOL_LENGTH;
if (ptr >= DSTAR_DATA_LENGTH_SAMPLES)
ptr -= DSTAR_DATA_LENGTH_SAMPLES;
@ -567,19 +570,20 @@ bool CDStarRX::correlateDataSync()
}
if (corr > m_maxDataCorr) {
uint16_t startPtr = m_dataPtr + DSTAR_FRAME_LENGTH_SAMPLES - DSTAR_SYNC_LENGTH_SAMPLES + DSTAR_RADIO_SYMBOL_LENGTH;
if (startPtr >= DSTAR_DATA_LENGTH_SAMPLES)
startPtr -= DSTAR_DATA_LENGTH_SAMPLES;
m_maxDataCorr = corr;
m_lostCount = MAX_SYNC_FRAMES;
m_syncPtr = m_dataPtr;
m_frameCount = 0U;
m_startPtr = startPtr;
m_startPtr = m_dataPtr + DSTAR_RADIO_SYMBOL_LENGTH;
if (m_startPtr >= DSTAR_DATA_LENGTH_SAMPLES)
m_startPtr -= DSTAR_DATA_LENGTH_SAMPLES;
m_endPtr = m_dataPtr + 2U;
if (m_endPtr >= DSTAR_DATA_LENGTH_SAMPLES)
m_endPtr -= DSTAR_DATA_LENGTH_SAMPLES;
m_maxSyncPtr = m_startPtr + DSTAR_DATA_LENGTH_SAMPLES + 2U;
if (m_maxSyncPtr >= DSTAR_DATA_LENGTH_SAMPLES)
m_maxSyncPtr -= DSTAR_DATA_LENGTH_SAMPLES;
m_minSyncPtr = m_startPtr + DSTAR_DATA_LENGTH_SAMPLES - 2U;
if (m_minSyncPtr >= DSTAR_DATA_LENGTH_SAMPLES)
m_minSyncPtr -= DSTAR_DATA_LENGTH_SAMPLES;
return true;
}
@ -588,7 +592,7 @@ bool CDStarRX::correlateDataSync()
return false;
}
void CDStarRX::samplesToBits(const uint8_t* inBuffer, uint16_t start, uint16_t count, uint8_t* outBuffer, uint16_t limit)
void CDStarRX::samplesToBits(const q15_t* inBuffer, uint16_t start, uint16_t count, uint8_t* outBuffer, uint16_t limit)
{
for (uint16_t i = 0U; i < count; i++) {
q15_t sample = inBuffer[start];

8
DStarRX.h
View File

@ -39,19 +39,17 @@ public:
private:
DSRX_STATE m_rxState;
uint32_t m_bitBuffer[DSTAR_RADIO_SYMBOL_LENGTH];
q15_t m_headerBuffer[DSTAR_FEC_SECTION_LENGTH_SAMPLES];
q15_t m_headerBuffer[DSTAR_FEC_SECTION_LENGTH_SAMPLES + DSTAR_RADIO_SYMBOL_LENGTH];
q15_t m_dataBuffer[DSTAR_DATA_LENGTH_SAMPLES];
uint16_t m_bitPtr;
uint16_t m_headerPtr;
uint16_t m_dataPtr;
uint16_t m_startPtr;
uint16_t m_endPtr;
uint16_t m_minSyncPtr;
uint16_t m_maxSyncPtr;
uint16_t m_syncPtr;
q31_t m_maxFrameCorr;
q31_t m_maxDataCorr;
uint16_t m_lostCount;
uint16_t m_frameCount;
uint8_t m_countdown;
unsigned int m_mar;
int m_pathMetric[4U];
@ -70,7 +68,7 @@ private:
void processData();
bool correlateFrameSync();
bool correlateDataSync();
void samplesToBits(const uint8_t* inBuffer, uint16_t start, uint16_t count, uint8_t* outBuffer, uint16_t limit);
void samplesToBits(const q15_t* inBuffer, uint16_t start, uint16_t count, uint8_t* outBuffer, uint16_t limit);
void writeRSSIHeader(unsigned char* header);
void writeRSSIData(unsigned char* data);
bool rxHeader(uint8_t* in, uint8_t* out);

14
DStarTX.cpp
View File

@ -198,7 +198,7 @@ m_txDelay(60U) // 100ms
{
::memset(m_modState, 0x00U, 20U * sizeof(q15_t));
m_modFilter.L = DSTAR_RADIO_BIT_LENGTH;
m_modFilter.L = DSTAR_RADIO_SYMBOL_LENGTH;
m_modFilter.phaseLength = GAUSSIAN_0_35_FILTER_PHASE_LEN;
m_modFilter.pCoeffs = GAUSSIAN_0_35_FILTER;
m_modFilter.pState = m_modState;
@ -252,8 +252,8 @@ void CDStarTX::process()
m_buffer.get();
for (uint8_t j = 0U; j < 3U; j++) {
for (uint8_t i = 0U; i < DSTAR_EOT_LENGTH_BYTES; i++)
m_poBuffer[m_poLen++] = DSTAR_EOT_BYTES[i];
for (uint8_t i = 0U; i < DSTAR_END_SYNC_LENGTH_BYTES; i++)
m_poBuffer[m_poLen++] = DSTAR_END_SYNC_BYTES[i];
}
m_poPtr = 0U;
@ -262,11 +262,11 @@ void CDStarTX::process()
if (m_poLen > 0U) {
uint16_t space = io.getSpace();
while (space > (8U * DSTAR_RADIO_BIT_LENGTH)) {
while (space > (8U * DSTAR_RADIO_SYMBOL_LENGTH)) {
uint8_t c = m_poBuffer[m_poPtr++];
writeByte(c);
space -= 8U * DSTAR_RADIO_BIT_LENGTH;
space -= 8U * DSTAR_RADIO_SYMBOL_LENGTH;
if (m_poPtr >= m_poLen) {
m_poPtr = 0U;
@ -412,7 +412,7 @@ void CDStarTX::txHeader(const uint8_t* in, uint8_t* out) const
void CDStarTX::writeByte(uint8_t c)
{
q15_t inBuffer[8U];
q15_t outBuffer[DSTAR_RADIO_BIT_LENGTH * 8U];
q15_t outBuffer[DSTAR_RADIO_SYMBOL_LENGTH * 8U];
uint8_t mask = 0x01U;
@ -427,7 +427,7 @@ void CDStarTX::writeByte(uint8_t c)
::arm_fir_interpolate_q15(&m_modFilter, inBuffer, outBuffer, 8U);
io.write(STATE_DSTAR, outBuffer, DSTAR_RADIO_BIT_LENGTH * 8U);
io.write(STATE_DSTAR, outBuffer, DSTAR_RADIO_SYMBOL_LENGTH * 8U);
}
void CDStarTX::setTXDelay(uint8_t delay)