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Add new interpolation for most modes and start positioning for P25 and YSF.
This commit is contained in:
Jonathan Naylor
parent
18ec4bafb6
commit
1bb474dfef
10 changed files with 212 additions and 136 deletions
108
P25RX.cpp
108
P25RX.cpp
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@ -18,7 +18,7 @@
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#define WANT_DEBUG
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// #define DUMP_SAMPLES
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#define DUMP_SAMPLES
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#include "Config.h"
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#include "Globals.h"
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@ -27,10 +27,12 @@
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const q15_t SCALING_FACTOR = 18750; // Q15(0.55)
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const uint8_t MAX_SYNC_SYMBOLS_ERRS = 2U;
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const uint8_t MAX_SYNC_BYTES_ERRS = 3U;
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const uint8_t MAX_SYNC_BIT_START_ERRS = 2U;
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const uint8_t MAX_SYNC_BIT_RUN_ERRS = 4U;
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const uint8_t BIT_MASK_TABLE[] = {0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U, 0x02U, 0x01U};
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const uint8_t MAX_SYNC_SYMBOLS_ERRS = 2U;
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const uint8_t BIT_MASK_TABLE[] = { 0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U, 0x02U, 0x01U };
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#define WRITE_BIT1(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE[(i)&7])
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@ -44,7 +46,9 @@ m_bitBuffer(),
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m_buffer(),
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m_bitPtr(0U),
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m_dataPtr(0U),
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m_endPtr(NOENDPTR),
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m_hdrStartPtr(NOENDPTR),
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m_lduStartPtr(NOENDPTR),
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m_lduEndPtr(NOENDPTR),
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m_minSyncPtr(NOENDPTR),
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m_maxSyncPtr(NOENDPTR),
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m_hdrSyncPtr(NOENDPTR),
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@ -71,7 +75,9 @@ void CP25RX::reset()
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m_bitPtr = 0U;
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m_maxCorr = 0;
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m_averagePtr = 0U;
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m_endPtr = NOENDPTR;
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m_hdrStartPtr = NOENDPTR;
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m_lduStartPtr = NOENDPTR;
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m_lduEndPtr = NOENDPTR;
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m_hdrSyncPtr = NOENDPTR;
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m_lduSyncPtr = NOENDPTR;
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m_minSyncPtr = NOENDPTR;
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@ -182,12 +188,8 @@ void CP25RX::processHdr(q15_t sample)
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if (m_lduSyncPtr >= m_minSyncPtr || m_lduSyncPtr <= m_maxSyncPtr)
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isSync = true;
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}
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if (isSync) {
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DEBUG4("P25RX, sync position in HDR, pos/min/max", m_lduSyncPtr, m_minSyncPtr, m_maxSyncPtr);
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uint16_t ptr = m_hdrSyncPtr + P25_LDU_FRAME_LENGTH_SAMPLES - P25_HDR_FRAME_LENGTH_SAMPLES - P25_SYNC_LENGTH_SAMPLES - 1U;
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if (ptr >= P25_LDU_FRAME_LENGTH_SAMPLES)
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ptr -= P25_LDU_FRAME_LENGTH_SAMPLES;
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if (isSync) {
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m_threshold[m_averagePtr] = m_thresholdBest;
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m_centre[m_averagePtr] = m_centreBest;
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@ -209,9 +211,9 @@ void CP25RX::processHdr(q15_t sample)
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DEBUG4("P25RX: sync found in Hdr pos/centre/threshold", m_hdrSyncPtr, m_centreVal, m_thresholdVal);
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uint8_t frame[P25_HDR_FRAME_LENGTH_BYTES + 1U];
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samplesToBits(ptr, P25_HDR_FRAME_LENGTH_SYMBOLS, frame, 8U, m_centreVal, m_thresholdVal);
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samplesToBits(m_hdrStartPtr, P25_HDR_FRAME_LENGTH_SYMBOLS, frame, 8U, m_centreVal, m_thresholdVal);
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#if defined(DUMP_SAMPLES)
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writeSync(ptr);
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writeSync(m_hdrStartPtr);
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#endif
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frame[0U] = 0x01U;
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@ -241,11 +243,7 @@ void CP25RX::processLdu(q15_t sample)
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correlateSync();
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}
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if (m_dataPtr == m_endPtr) {
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uint16_t ptr = m_endPtr + P25_RADIO_SYMBOL_LENGTH + 1U;
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if (ptr >= P25_LDU_FRAME_LENGTH_SAMPLES)
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ptr -= P25_LDU_FRAME_LENGTH_SAMPLES;
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if (m_dataPtr == m_lduEndPtr) {
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// Only update the centre and threshold if they are from a good sync
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if (m_lostCount == MAX_SYNC_FRAMES) {
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m_threshold[m_averagePtr] = m_thresholdBest;
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@ -278,9 +276,9 @@ void CP25RX::processLdu(q15_t sample)
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}
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uint8_t frame[P25_LDU_FRAME_LENGTH_BYTES + 3U];
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samplesToBits(ptr, P25_LDU_FRAME_LENGTH_SYMBOLS, frame, 8U, m_centreVal, m_thresholdVal);
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samplesToBits(m_lduStartPtr, P25_LDU_FRAME_LENGTH_SYMBOLS, frame, 8U, m_centreVal, m_thresholdVal);
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#if defined(DUMP_SAMPLES)
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writeSync(ptr);
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writeSync(m_lduStartPtr);
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#endif
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// We've not seen a data sync for too long, signal RXLOST and change to RX_NONE
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@ -293,9 +291,9 @@ void CP25RX::processLdu(q15_t sample)
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serial.writeP25Lost();
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m_state = P25RXS_NONE;
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m_endPtr = NOENDPTR;
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m_maxCorr = 0;
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m_state = P25RXS_NONE;
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m_lduEndPtr = NOENDPTR;
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m_maxCorr = 0;
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} else {
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frame[0U] = m_lostCount == (MAX_SYNC_FRAMES - 1U) ? 0x01U : 0x00U;
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@ -317,16 +315,28 @@ bool CP25RX::correlateSync()
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q15_t max = -16000;
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q15_t min = 16000;
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uint32_t mask = 0x00080000U;
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for (uint8_t i = 0U; i < P25_SYNC_LENGTH_SYMBOLS; i++, mask >>= 1) {
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bool b = (P25_SYNC_SYMBOLS & mask) == mask;
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for (uint8_t i = 0U; i < P25_SYNC_LENGTH_SYMBOLS; i++) {
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q15_t val = m_buffer[ptr];
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if (m_buffer[ptr] > max)
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max = m_buffer[ptr];
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if (m_buffer[ptr] < min)
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min = m_buffer[ptr];
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if (val > max)
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max = val;
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if (val < min)
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min = val;
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corr += b ? -m_buffer[ptr] : m_buffer[ptr];
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switch (P25_SYNC_SYMBOLS_VALUES[i]) {
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case +3:
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corr -= (val + val + val);
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break;
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case +1:
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corr -= val;
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break;
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case -1:
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corr += val;
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break;
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default: // -3
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corr += (val + val + val);
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break;
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}
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ptr += P25_RADIO_SYMBOL_LENGTH;
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if (ptr >= P25_LDU_FRAME_LENGTH_SAMPLES)
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@ -341,35 +351,45 @@ bool CP25RX::correlateSync()
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uint8_t sync[P25_SYNC_BYTES_LENGTH];
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uint16_t ptr = m_dataPtr + P25_LDU_FRAME_LENGTH_SAMPLES - P25_SYNC_LENGTH_SAMPLES + P25_RADIO_SYMBOL_LENGTH;
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if (ptr >= P25_LDU_FRAME_LENGTH_SAMPLES)
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ptr -= P25_LDU_FRAME_LENGTH_SAMPLES;
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uint16_t startPtr = m_dataPtr + P25_LDU_FRAME_LENGTH_SAMPLES - P25_SYNC_LENGTH_SAMPLES + P25_RADIO_SYMBOL_LENGTH;
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if (startPtr >= P25_LDU_FRAME_LENGTH_SAMPLES)
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startPtr -= P25_LDU_FRAME_LENGTH_SAMPLES;
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if (m_state == P25RXS_NONE)
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samplesToBits(ptr, P25_SYNC_LENGTH_SYMBOLS, sync, 0U, centre, threshold);
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else
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samplesToBits(ptr, P25_SYNC_LENGTH_SYMBOLS, sync, 0U, m_centreVal, m_thresholdVal);
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uint8_t maxErrs;
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if (m_state == P25RXS_NONE) {
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samplesToBits(startPtr, P25_SYNC_LENGTH_SYMBOLS, sync, 0U, centre, threshold);
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maxErrs = MAX_SYNC_BIT_START_ERRS;
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} else {
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samplesToBits(startPtr, P25_SYNC_LENGTH_SYMBOLS, sync, 0U, m_centreVal, m_thresholdVal);
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maxErrs = MAX_SYNC_BIT_RUN_ERRS;
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}
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uint8_t errs = 0U;
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for (uint8_t i = 0U; i < P25_SYNC_BYTES_LENGTH; i++)
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errs += countBits8(sync[i] ^ P25_SYNC_BYTES[i]);
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if (errs <= MAX_SYNC_BYTES_ERRS) {
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if (errs <= maxErrs) {
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m_maxCorr = corr;
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m_thresholdBest = threshold;
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m_centreBest = centre;
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m_lostCount = MAX_SYNC_FRAMES;
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m_lduSyncPtr = m_dataPtr;
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// This is the position of the end of a normal LDU
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m_endPtr = m_dataPtr + P25_LDU_FRAME_LENGTH_SAMPLES - P25_SYNC_LENGTH_SAMPLES - 1U;
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if (m_endPtr >= P25_LDU_FRAME_LENGTH_SAMPLES)
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m_endPtr -= P25_LDU_FRAME_LENGTH_SAMPLES;
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// These are the positions of the start and end of an LDU
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m_lduStartPtr = startPtr;
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m_lduEndPtr = m_dataPtr + P25_LDU_FRAME_LENGTH_SAMPLES - P25_SYNC_LENGTH_SAMPLES - 1U;
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if (m_lduEndPtr >= P25_LDU_FRAME_LENGTH_SAMPLES)
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m_lduEndPtr -= P25_LDU_FRAME_LENGTH_SAMPLES;
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// These are the positions of the sync in the following LDU if the HDR is present
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if (m_state == P25RXS_NONE) {
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m_hdrSyncPtr = m_dataPtr;
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// This is the position of the start of a HDR
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m_hdrStartPtr = startPtr;
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// These are the range of positions for a sync for an LDU following a HDR
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m_minSyncPtr = m_dataPtr + P25_HDR_FRAME_LENGTH_SAMPLES - 1U;
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if (m_minSyncPtr >= P25_LDU_FRAME_LENGTH_SAMPLES)
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m_minSyncPtr -= P25_LDU_FRAME_LENGTH_SAMPLES;
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