Merge branch 'boxcar_dstar_correlator' into boxcar_dstar_correlator_48k

Fixes erroneous end sync seen on station having QSB

CWIdTX.cpp

@@ -22,12 +22,12 @@
 #include "CWIdTX.h"
 
 q15_t TONE[] = {
-    0, 518, 1000, 1414, 1732, 1932, 2000, 1932, 1732, 1414, 1000, 518, 0, -518, -1000, -1414, -1732, -1932, -2000, -1932, -1732, -1414, -1000, -518};
-
+    0, 261, 518, 765, 1000, 1218, 1414, 1587, 1732, 1848, 1932, 1983, 2000, 1983, 1932, 1848, 1732, 1587, 1414, 1218, 1000, 765, 518, 261, 0, -261, -518, -765, -1000, -1218, -1414,
+    -1587, -1732, -1848, -1932, -1983, -2000, -1983, -1932, -1848, -1732, -1587, -1414, -1218, -1000, -765, -518, -261};
 q15_t SILENCE[] = {
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
 
-const uint8_t CYCLE_LENGTH = 24U;
+const uint8_t CYCLE_LENGTH = 48U;
 
 const uint8_t DOT_LENGTH = 50U;
 

CalDStarRX.cpp

@@ -24,7 +24,7 @@
 const unsigned int BUFFER_LENGTH = 200U;
 
 const uint32_t PLLMAX = 0x10000U;
-const uint32_t PLLINC = PLLMAX / DSTAR_RADIO_BIT_LENGTH;
+const uint32_t PLLINC = PLLMAX / DSTAR_RADIO_SYMBOL_LENGTH;
 const uint32_t INC    = PLLINC / 32U;
 
 // D-Star bit order version of 0x55 0x2D 0x16

DMRDMORX.h

@@ -22,7 +22,7 @@
 #include "Config.h"
 #include "DMRDefines.h"
 
-const uint16_t DMO_BUFFER_LENGTH_SAMPLES = 1440U;   // 60ms at 24 kHz
+const uint16_t DMO_BUFFER_LENGTH_SAMPLES = 2880U;   // 60ms at 48 kHz
 
 enum DMORX_STATE {
   DMORXS_NONE,

DMRDMOTX.cpp

@@ -22,10 +22,16 @@
 #include "Globals.h"
 #include "DMRSlotType.h"
 
-// Generated using rcosdesign(0.2, 8, 5, 'sqrt') in MATLAB
-static q15_t RRC_0_2_FILTER[] = {0, 0, 0, 0, 850, 219, -720, -1548, -1795, -1172, 237, 1927, 3120, 3073, 1447, -1431, -4544, -6442,
-                                 -5735, -1633, 5651, 14822, 23810, 30367, 32767, 30367, 23810, 14822, 5651, -1633, -5735, -6442,
-                                 -4544, -1431, 1447, 3073, 3120, 1927, 237, -1172, -1795, -1548, -720, 219, 850}; // numTaps = 45, L = 5
+// Generated using rcosdesign(0.2, 8, 10, 'sqrt') in MATLAB
+static q15_t RRC_0_2_FILTER[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 850, 592, 219, -234, -720, -1179,
+                                -1548, -1769, -1795, -1597, -1172, -544, 237, 1092, 1927, 2637,
+                                3120, 3286, 3073, 2454, 1447, 116, -1431, -3043, -4544, -5739,
+                                -6442, -6483, -5735, -4121, -1633, 1669, 5651, 10118, 14822,
+                                19484, 23810, 27520, 30367, 32156, 32767, 32156, 30367, 27520,
+                                23810, 19484, 14822, 10118, 5651, 1669, -1633, -4121, -5735,
+                                -6483, -6442, -5739, -4544, -3043, -1431, 116, 1447, 2454,
+                                3073, 3286, 3120, 2637, 1927, 1092, 237, -544, -1172, -1597,
+                                -1795, -1769, -1548, -1179, -720, -234, 219, 592, 850}; // numTaps = 90, L = 10
 const uint16_t RRC_0_2_FILTER_PHASE_LEN = 9U; // phaseLength = numTaps/L
 
 const q15_t DMR_LEVELA =  1362;

DMRDefines.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2016 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -19,7 +19,7 @@
 #if !defined(DMRDEFINES_H)
 #define  DMRDEFINES_H
 
-const unsigned int DMR_RADIO_SYMBOL_LENGTH = 5U;      // At 24 kHz sample rate
+const unsigned int DMR_RADIO_SYMBOL_LENGTH = 10U;      // At 48 kHz sample rate
 
 const unsigned int DMR_FRAME_LENGTH_BYTES   = 33U;
 const unsigned int DMR_FRAME_LENGTH_BITS    = DMR_FRAME_LENGTH_BYTES * 8U;

DMRSlotRX.cpp

@@ -22,8 +22,8 @@
 #include "DMRSlotType.h"
 #include "Utils.h"
 
-const uint16_t SCAN_START = 400U;
-const uint16_t SCAN_END   = 490U;
+const uint16_t SCAN_START = 790U;
+const uint16_t SCAN_END   = 920U;
 
 const q15_t SCALING_FACTOR = 19505;      // Q15(0.60)
 
@@ -97,7 +97,7 @@ bool CDMRSlotRX::processSample(q15_t sample, uint16_t rssi)
     return m_state != DMRRXS_NONE;
 
   // Ensure that the buffer doesn't overflow
-  if (m_dataPtr > m_endPtr || m_dataPtr >= 900U)
+  if (m_dataPtr > m_endPtr || m_dataPtr >= 1900U)
     return m_state != DMRRXS_NONE;
 
   m_buffer[m_dataPtr] = sample;

DMRSlotRX.h

@@ -44,7 +44,7 @@ public:
 private:
   bool        m_slot;
   uint32_t    m_bitBuffer[DMR_RADIO_SYMBOL_LENGTH];
-  q15_t       m_buffer[900U];
+  q15_t       m_buffer[1900U];
   uint16_t    m_bitPtr;
   uint16_t    m_dataPtr;
   uint16_t    m_syncPtr;
@@ -62,7 +62,7 @@ private:
   DMRRX_STATE m_state;
   uint8_t     m_n;
   uint8_t     m_type;
-  uint16_t    m_rssi[900U];
+  uint16_t    m_rssi[1900U];
 
   void correlateSync(bool first);
   void samplesToBits(uint16_t start, uint8_t count, uint8_t* buffer, uint16_t offset, q15_t centre, q15_t threshold);

DMRTX.cpp

@@ -22,10 +22,16 @@
 #include "Globals.h"
 #include "DMRSlotType.h"
 
-// Generated using rcosdesign(0.2, 8, 5, 'sqrt') in MATLAB
-static q15_t RRC_0_2_FILTER[] = {0, 0, 0, 0, 850, 219, -720, -1548, -1795, -1172, 237, 1927, 3120, 3073, 1447, -1431, -4544, -6442,
-                                 -5735, -1633, 5651, 14822, 23810, 30367, 32767, 30367, 23810, 14822, 5651, -1633, -5735, -6442,
-                                 -4544, -1431, 1447, 3073, 3120, 1927, 237, -1172, -1795, -1548, -720, 219, 850}; // numTaps = 45, L = 5
+// Generated using rcosdesign(0.2, 8, 10, 'sqrt') in MATLAB
+static q15_t RRC_0_2_FILTER[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 850, 592, 219, -234, -720, -1179,
+                                -1548, -1769, -1795, -1597, -1172, -544, 237, 1092, 1927, 2637,
+                                3120, 3286, 3073, 2454, 1447, 116, -1431, -3043, -4544, -5739,
+                                -6442, -6483, -5735, -4121, -1633, 1669, 5651, 10118, 14822,
+                                19484, 23810, 27520, 30367, 32156, 32767, 32156, 30367, 27520,
+                                23810, 19484, 14822, 10118, 5651, 1669, -1633, -4121, -5735,
+                                -6483, -6442, -5739, -4544, -3043, -1431, 116, 1447, 2454,
+                                3073, 3286, 3120, 2637, 1927, 1092, 237, -544, -1172, -1597,
+                                -1795, -1769, -1548, -1179, -720, -234, 219, 592, 850}; // numTaps = 90, L = 10
 const uint16_t RRC_0_2_FILTER_PHASE_LEN = 9U; // phaseLength = numTaps/L
 
 const q15_t DMR_LEVELA =  1362;

DStarDefines.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2015 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2015,2017 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -19,30 +19,50 @@
 #if !defined(DSTARDEFINES_H)
 #define  DSTARDEFINES_H
 
-const unsigned int DSTAR_RADIO_BIT_LENGTH = 5U;      // At 24 kHz sample rate
+const unsigned int DSTAR_RADIO_SYMBOL_LENGTH = 10U;      // At 48 kHz sample rate
 
-const unsigned int DSTAR_HEADER_LENGTH_BYTES = 41U;
-const unsigned int DSTAR_HEADER_LENGTH_BITS  = DSTAR_HEADER_LENGTH_BYTES * 8U;
+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_BYTES   = 83U;
+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_BYTES   = 12U;
+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 uint8_t      DSTAR_EOT_BYTES[] = {0x55, 0x55, 0x55, 0x55, 0xC8, 0x7A, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
-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 uint8_t      DSTAR_DATA_SYNC_LENGTH_BYTES = 3U;
-const uint8_t      DSTAR_DATA_SYNC_LENGTH_BITS  = DSTAR_DATA_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 uint8_t      DSTAR_DATA_SYNC_BYTES[] = {0x9E, 0x8D, 0x32, 0x88, 0x26, 0x1A, 0x3F, 0x61, 0xE8, 0x55, 0x2D, 0x16};
+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_SLOW_DATA_TYPE_TEXT   = 0x40U;
-const uint8_t      DSTAR_SLOW_DATA_TYPE_HEADER = 0x50U;
+const uint8_t DSTAR_DATA_SYNC_BYTES[] = {0x9E, 0x8D, 0x32, 0x88, 0x26, 0x1A, 0x3F, 0x61, 0xE8, 0x55, 0x2D, 0x16};
 
-const uint8_t      DSTAR_SCRAMBLER_BYTES[] = {0x70U, 0x4FU, 0x93U};
+// D-Star bit order version of 0x55 0x6E 0x0A
+const uint32_t DSTAR_FRAME_SYNC_DATA = 0x00557650U;
+const uint32_t DSTAR_FRAME_SYNC_MASK = 0x00FFFFFFU;
+const bool     DSTAR_FRAME_SYNC_SYMBOLS[] = {false, true, false, true, false, true, false, true, false, true, true, true, false, true, true, false, false, true, false, true, false, false, false, false};
+
+// D-Star bit order version of 0x55 0x2D 0x16
+const uint32_t DSTAR_DATA_SYNC_DATA = 0x00AAB468U;
+const uint32_t DSTAR_DATA_SYNC_MASK = 0x00FFFFFFU;
+const bool     DSTAR_DATA_SYNC_SYMBOLS[] = {true, false, true, false, true, false, true, false, true, false, true, true, false, true, false, false, false, true, true, false, true, false, false, false};
+
+// D-Star bit order version of 0x55 0x55 0xC8 0x7A
+const uint32_t DSTAR_END_SYNC_DATA = 0xAAAA135EU;
+const uint32_t DSTAR_END_SYNC_MASK = 0xFFFFFFFFU;
+const uint8_t  DSTAR_END_SYNC_BYTES[] = {0x55, 0x55, 0x55, 0x55, 0xC8, 0x7A, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+
+const uint8_t  DSTAR_SLOW_DATA_TYPE_TEXT   = 0x40U;
+const uint8_t  DSTAR_SLOW_DATA_TYPE_HEADER = 0x50U;
+
+const uint8_t  DSTAR_SCRAMBLER_BYTES[] = {0x70U, 0x4FU, 0x93U};
 
 #endif
 

DStarRX.cpp

@@ -22,18 +22,12 @@
 #include "DStarRX.h"
 #include "Utils.h"
 
-const unsigned int BUFFER_LENGTH = 200U;
-
-const uint32_t PLLMAX = 0x10000U;
-const uint32_t PLLINC = PLLMAX / DSTAR_RADIO_BIT_LENGTH;
-const uint32_t INC    = PLLINC / 32U;
-
-const unsigned int MAX_SYNC_BITS = 100U * DSTAR_DATA_LENGTH_BITS;
+const unsigned int MAX_FRAMES = 150U;
 
 // D-Star bit order version of 0x55 0x55 0x6E 0x0A
 const uint32_t FRAME_SYNC_DATA = 0x00557650U;
 const uint32_t FRAME_SYNC_MASK = 0x00FFFFFFU;
-const uint8_t  FRAME_SYNC_ERRS = 2U;
+const uint8_t  FRAME_SYNC_ERRS = 1U;
 
 // D-Star bit order version of 0x55 0x2D 0x16
 const uint32_t DATA_SYNC_DATA = 0x00AAB468U;
@@ -237,14 +231,24 @@ const uint16_t CCITT_TABLE[] = {
   0xf78fU, 0xe606U, 0xd49dU, 0xc514U, 0xb1abU, 0xa022U, 0x92b9U, 0x8330U,
   0x7bc7U, 0x6a4eU, 0x58d5U, 0x495cU, 0x3de3U, 0x2c6aU, 0x1ef1U, 0x0f78U};
 
+const uint16_t NOENDPTR = 9999U;
+
 CDStarRX::CDStarRX() :
-m_pll(0U),
-m_prev(false),
 m_rxState(DSRXS_NONE),
-m_patternBuffer(0x00U),
-m_rxBuffer(),
-m_rxBufferBits(0U),
-m_dataBits(0U),
+m_bitBuffer(),
+m_headerBuffer(),
+m_dataBuffer(),
+m_bitPtr(0U),
+m_headerPtr(0U),
+m_dataPtr(0U),
+m_startPtr(NOENDPTR),
+m_syncPtr(NOENDPTR),
+m_minSyncPtr(NOENDPTR),
+m_maxSyncPtr(NOENDPTR),
+m_maxFrameCorr(0),
+m_maxDataCorr(0),
+m_frameCount(0U),
+m_countdown(0U),
 m_mar(0U),
 m_pathMetric(),
 m_pathMemory0(),
@@ -259,14 +263,20 @@ m_rssiCount(0U)
 
 void CDStarRX::reset()
 {
-  m_pll           = 0U;
-  m_prev          = false;
-  m_rxState       = DSRXS_NONE;
-  m_patternBuffer = 0x00U;
-  m_rxBufferBits  = 0U;
-  m_dataBits      = 0U;
-  m_rssiAccum     = 0U;
-  m_rssiCount     = 0U;
+  m_rxState      = DSRXS_NONE;
+  m_headerPtr    = 0U;
+  m_dataPtr      = 0U;
+  m_bitPtr       = 0U;
+  m_maxFrameCorr = 0;
+  m_maxDataCorr  = 0;
+  m_startPtr     = NOENDPTR;
+  m_syncPtr      = NOENDPTR;
+  m_minSyncPtr   = NOENDPTR;
+  m_maxSyncPtr   = NOENDPTR;
+  m_frameCount   = 0U;
+  m_countdown    = 0U;
+  m_rssiAccum    = 0U;
+  m_rssiCount    = 0U;
 }
 
 void CDStarRX::samples(const q15_t* samples, const uint16_t* rssi, uint8_t length)
@@ -275,125 +285,117 @@ void CDStarRX::samples(const q15_t* samples, const uint16_t* rssi, uint8_t lengt
     m_rssiAccum += rssi[i];
     m_rssiCount++;
 
-    bool bit = samples[i] < 0;
+    q15_t sample = samples[i];
 
-    if (bit != m_prev) {
-      if (m_pll < (PLLMAX / 2U))
-        m_pll += INC;
-      else
-        m_pll -= INC;
+    m_bitBuffer[m_bitPtr] <<= 1;
+    if (sample < 0)
+      m_bitBuffer[m_bitPtr] |= 0x01U;
+
+    m_dataBuffer[m_dataPtr] = sample;
+
+    switch (m_rxState) {
+      case DSRXS_HEADER:
+        processHeader(sample);
+        break;
+      case DSRXS_DATA:
+        processData();
+        break;
+      default:
+        processNone(sample);
+        break;
     }
 
-    m_prev = bit;
+    m_dataPtr++;
+    if (m_dataPtr >= DSTAR_DATA_LENGTH_SAMPLES)
+      m_dataPtr = 0U;
 
-    m_pll += PLLINC;
-
-    if (m_pll >= PLLMAX) {
-      m_pll -= PLLMAX;
-
-      switch (m_rxState) {
-        case DSRXS_NONE:
-          processNone(bit);
-          break;
-        case DSRXS_HEADER:
-          processHeader(bit);
-          break;
-        case DSRXS_DATA:
-          processData(bit);
-          break;
-        default:
-          break;
-      }
-    }
+    m_bitPtr++;
+    if (m_bitPtr >= DSTAR_RADIO_SYMBOL_LENGTH)
+      m_bitPtr = 0U;
   }
 }
 
-void CDStarRX::processNone(bool bit)
+void CDStarRX::processNone(q15_t sample)
 {
-  m_patternBuffer <<= 1;
-  if (bit)
-    m_patternBuffer |= 0x01U;
-
   // Fuzzy matching of the frame sync sequence
-  if (countBits32((m_patternBuffer & FRAME_SYNC_MASK) ^ FRAME_SYNC_DATA) <= FRAME_SYNC_ERRS) {
-    DEBUG1("DStarRX: found frame sync in None");
-
-    ::memset(m_rxBuffer, 0x00U, DSTAR_FEC_SECTION_LENGTH_BYTES);
-    m_rxBufferBits = 0U;
+  bool ret = correlateFrameSync();
+  if (ret) {
+    m_countdown = 5U;
+	
+    m_headerBuffer[m_headerPtr] = sample;
+    m_headerPtr++;
 
     m_rssiAccum = 0U;
     m_rssiCount = 0U;
 
     m_rxState = DSRXS_HEADER;
+
     return;
   }
 
-  // Exact matching of the data sync bit sequence
-  if (countBits32((m_patternBuffer & DATA_SYNC_MASK) ^ DATA_SYNC_DATA) == 0U) {
+  // Fuzzy matching of the data sync bit sequence
+  ret = correlateDataSync();
+  if (ret) {
     DEBUG1("DStarRX: found data sync in None");
 
     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  = MAX_SYNC_BITS;
-    m_rxState   = DSRXS_DATA;
-    return;
+    m_rxState = DSRXS_DATA;
   }
 }
 
-void CDStarRX::processHeader(bool bit)
+void CDStarRX::processHeader(q15_t sample)
 {
-  m_patternBuffer <<= 1;
-  if (bit)
-    m_patternBuffer |= 0x01U;
+  if (m_countdown > 0U) {
+    correlateFrameSync();
+    m_countdown--;
+  }
 
-  WRITE_BIT2(m_rxBuffer, m_rxBufferBits, bit);
-  m_rxBufferBits++;
+  m_headerBuffer[m_headerPtr] = sample;
+  m_headerPtr++;
 
   // A full FEC header
-  if (m_rxBufferBits == DSTAR_FEC_SECTION_LENGTH_BITS) {
-    // Process the scrambling, interleaving and FEC, then return if the chcksum was correct
-    unsigned char header[DSTAR_HEADER_LENGTH_BYTES];
-    bool ok = rxHeader(m_rxBuffer, header);
-    if (ok) {
+  if (m_headerPtr == (DSTAR_FEC_SECTION_LENGTH_SAMPLES + DSTAR_RADIO_SYMBOL_LENGTH)) {
+    uint8_t buffer[DSTAR_FEC_SECTION_LENGTH_BYTES];
+    samplesToBits(m_headerBuffer, DSTAR_RADIO_SYMBOL_LENGTH, 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) {
+      // The checksum failed, return to looking for syncs
+      m_rxState = DSRXS_NONE;
+      m_maxFrameCorr = 0;
+      m_maxDataCorr  = 0;
+    } else {
       io.setDecode(true);
       io.setADCDetection(true);
 
       writeRSSIHeader(header);
-
-      ::memset(m_rxBuffer, 0x00U, DSTAR_DATA_LENGTH_BYTES + 2U);
-      m_rxBufferBits = 0U;
-
-      m_rxState  = DSRXS_DATA;
-      m_dataBits = MAX_SYNC_BITS;
-    } else {
-      // The checksum failed, return to looking for syncs
-      m_rxState = DSRXS_NONE;
     }
   }
+
+  // Ready to start the first data section
+  if (m_headerPtr == (DSTAR_FEC_SECTION_LENGTH_SAMPLES + 2U * DSTAR_RADIO_SYMBOL_LENGTH)) {
+    m_frameCount = 0U;
+    m_dataPtr    = 0U;
+
+    m_startPtr   = 952U;
+    m_syncPtr    = 942U;
+    m_maxSyncPtr = 944U;
+    m_minSyncPtr = 940U;
+
+    DEBUG5("DStarRX: calc start/sync/max/min", m_startPtr, m_syncPtr, m_maxSyncPtr, m_minSyncPtr);
+
+    m_rxState = DSRXS_DATA;
+  }
 }
 
-void CDStarRX::processData(bool bit)
+void CDStarRX::processData()
 {
-  m_patternBuffer <<= 1;
-  if (bit)
-    m_patternBuffer |= 0x01U;
-
-  WRITE_BIT2(m_rxBuffer, m_rxBufferBits, bit);
-  m_rxBufferBits++;
-
   // Fuzzy matching of the end frame sequences
-  if (countBits32((m_patternBuffer & END_SYNC_MASK) ^ END_SYNC_DATA) <= END_SYNC_ERRS) {
+  if (countBits32((m_bitBuffer[m_bitPtr] & DSTAR_END_SYNC_MASK) ^ DSTAR_END_SYNC_DATA) <= END_SYNC_ERRS) {
     DEBUG1("DStarRX: Found end sync in Data");
 
     io.setDecode(false);
@@ -401,35 +403,24 @@ void CDStarRX::processData(bool bit)
 
     serial.writeDStarEOT();
 
+    m_maxFrameCorr = 0;
+    m_maxDataCorr  = 0;
+
     m_rxState = DSRXS_NONE;
     return;
   }
 
   // Fuzzy matching of the data sync bit sequence
-  bool syncSeen = false;
-  if (m_rxBufferBits >= (DSTAR_DATA_LENGTH_BITS - 3U)) {
-    if (countBits32((m_patternBuffer & DATA_SYNC_MASK) ^ DATA_SYNC_DATA) <= DATA_SYNC_ERRS) {
-      m_rxBufferBits = DSTAR_DATA_LENGTH_BITS;
-      m_dataBits     = MAX_SYNC_BITS;
-      syncSeen       = true;
-    }
+  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();
   }
 
-  // Check to see if the sync is arriving late
-  if (m_rxBufferBits == DSTAR_DATA_LENGTH_BITS && !syncSeen) {
-    for (uint8_t i = 1U; i <= 3U; i++) {
-      uint32_t syncMask = DATA_SYNC_MASK >> i;
-      uint32_t syncData = DATA_SYNC_DATA >> i;
-      if (countBits32((m_patternBuffer & syncMask) ^ syncData) <= DATA_SYNC_ERRS) {
-        m_rxBufferBits -= i;
-        break;
-      }
-    }
-  }
-
-  m_dataBits--;
-
-  if (m_dataBits == 0U) {
+  // We've not seen a data sync for too long, signal RXLOST and change to RX_NONE
+  if (m_frameCount >= MAX_FRAMES) {
     DEBUG1("DStarRX: data sync timed out, lost lock");
 
     io.setDecode(false);
@@ -437,24 +428,35 @@ void CDStarRX::processData(bool bit)
 
     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, or if a data sync has been seen
-  if (m_rxBufferBits == DSTAR_DATA_LENGTH_BITS) {
-    if (syncSeen) {
-      m_rxBuffer[9U]  = DSTAR_DATA_SYNC_BYTES[9U];
-      m_rxBuffer[10U] = DSTAR_DATA_SYNC_BYTES[10U];
-      m_rxBuffer[11U] = DSTAR_DATA_SYNC_BYTES[11U];
-	    writeRSSIData(m_rxBuffer);
-    } else {
-	    serial.writeDStarData(m_rxBuffer, DSTAR_DATA_LENGTH_BYTES);
-	  }
+  // Send a data frame to the host if the required number of bits have been received
+  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);
 
-    // Start the next frame
-    ::memset(m_rxBuffer, 0x00U, DSTAR_DATA_LENGTH_BYTES + 2U);
-    m_rxBufferBits = 0U;
+    if ((m_frameCount % 21U) == 0U) {
+      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];
+        DEBUG5("DStarRX: found start/sync/max/min", m_startPtr, m_syncPtr, m_maxSyncPtr, m_minSyncPtr);
+      }
+
+      writeRSSIData(buffer);
+    } else {
+      serial.writeDStarData(buffer, DSTAR_DATA_LENGTH_BYTES);
+    }
+
+    m_frameCount++;
+
+    m_maxFrameCorr = 0;
+    m_maxDataCorr  = 0;
   }
 }
 
@@ -500,6 +502,105 @@ void CDStarRX::writeRSSIData(unsigned char* data)
   m_rssiCount = 0U;
 }
 
+bool CDStarRX::correlateFrameSync()
+{
+  if (countBits32((m_bitBuffer[m_bitPtr] & DSTAR_FRAME_SYNC_MASK) ^ DSTAR_FRAME_SYNC_DATA) <= FRAME_SYNC_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;
+
+    q31_t corr = 0;
+
+    for (uint8_t i = 0U; i < DSTAR_FRAME_SYNC_LENGTH_SYMBOLS; i++) {
+      q15_t val = m_dataBuffer[ptr];
+
+      if (DSTAR_FRAME_SYNC_SYMBOLS[i])
+        corr -= val;
+      else
+        corr += val;
+
+      ptr += DSTAR_RADIO_SYMBOL_LENGTH;
+      if (ptr >= DSTAR_DATA_LENGTH_SAMPLES)
+        ptr -= DSTAR_DATA_LENGTH_SAMPLES;
+    }
+
+    if (corr > m_maxFrameCorr) {
+      m_maxFrameCorr = corr;
+      m_headerPtr    = 0U;
+      return true;
+    }
+  }
+
+  return false;
+}
+
+bool CDStarRX::correlateDataSync()
+{
+  uint8_t maxErrs = 0U;
+  if (m_rxState == DSRXS_DATA)
+    maxErrs = DATA_SYNC_ERRS;
+
+  if (countBits32((m_bitBuffer[m_bitPtr] & DSTAR_DATA_SYNC_MASK) ^ DSTAR_DATA_SYNC_DATA) <= maxErrs) {
+    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;
+
+    q31_t corr = 0;
+
+    for (uint8_t i = 0U; i < DSTAR_DATA_SYNC_LENGTH_SYMBOLS; i++) {
+      q15_t val = m_dataBuffer[ptr];
+
+      if (DSTAR_DATA_SYNC_SYMBOLS[i])
+        corr -= val;
+      else
+        corr += val;
+
+      ptr += DSTAR_RADIO_SYMBOL_LENGTH;
+      if (ptr >= DSTAR_DATA_LENGTH_SAMPLES)
+        ptr -= DSTAR_DATA_LENGTH_SAMPLES;
+    }
+
+    if (corr > m_maxDataCorr) {
+      m_maxDataCorr = corr;
+      m_frameCount  = 0U;
+
+      m_syncPtr    = m_dataPtr;
+
+      m_startPtr   = m_dataPtr + DSTAR_RADIO_SYMBOL_LENGTH;
+      if (m_startPtr >= DSTAR_DATA_LENGTH_SAMPLES)
+        m_startPtr -= DSTAR_DATA_LENGTH_SAMPLES;
+
+      m_maxSyncPtr = m_syncPtr + 1U;
+      if (m_maxSyncPtr >= DSTAR_DATA_LENGTH_SAMPLES)
+        m_maxSyncPtr -= DSTAR_DATA_LENGTH_SAMPLES;
+
+      m_minSyncPtr = m_syncPtr + DSTAR_DATA_LENGTH_SAMPLES - 1U;
+      if (m_minSyncPtr >= DSTAR_DATA_LENGTH_SAMPLES)
+        m_minSyncPtr -= DSTAR_DATA_LENGTH_SAMPLES;
+
+      return true;
+    }
+  }
+
+  return false;
+}
+
+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];
+
+    if (sample < 0)
+      WRITE_BIT2(outBuffer, i, true);
+    else
+      WRITE_BIT2(outBuffer, i, false);
+
+    start += DSTAR_RADIO_SYMBOL_LENGTH;
+    if (start >= limit)
+      start -= limit;
+  }
+}
+
 bool CDStarRX::rxHeader(uint8_t* in, uint8_t* out)
 {
   int i;

DStarRX.h

@@ -37,13 +37,21 @@ public:
   void reset();
 
 private:
-  uint32_t     m_pll;
-  bool         m_prev;
   DSRX_STATE   m_rxState;
-  uint32_t     m_patternBuffer;
-  uint8_t      m_rxBuffer[100U];
-  unsigned int m_rxBufferBits;
-  unsigned int m_dataBits;
+  uint32_t     m_bitBuffer[DSTAR_RADIO_SYMBOL_LENGTH];
+  q15_t        m_headerBuffer[DSTAR_FEC_SECTION_LENGTH_SAMPLES + 2U * 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_syncPtr;
+  uint16_t     m_minSyncPtr;
+  uint16_t     m_maxSyncPtr;
+  q31_t        m_maxFrameCorr;
+  q31_t        m_maxDataCorr;
+  uint16_t     m_frameCount;
+  uint8_t      m_countdown;
   unsigned int m_mar;
   int          m_pathMetric[4U];
   unsigned int m_pathMemory0[42U];
@@ -54,9 +62,12 @@ private:
   uint32_t     m_rssiAccum;
   uint16_t     m_rssiCount;
   
-  void    processNone(bool bit);
-  void    processHeader(bool bit);
-  void    processData(bool bit);
+  void    processNone(q15_t sample);
+  void    processHeader(q15_t sample);
+  void    processData();
+  bool    correlateFrameSync();
+  bool    correlateDataSync();
+  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);

DStarTX.cpp

@@ -27,8 +27,10 @@ const uint8_t BIT_SYNC = 0xAAU;
 
 const uint8_t FRAME_SYNC[] = {0xEAU, 0xA6U, 0x00U};
 
-// Generated using gaussfir(0.35, 1, 5) in MATLAB
-static q15_t GAUSSIAN_0_35_FILTER[] = {0, 0, 0, 0, 1001, 3514, 9333, 18751, 28499, 32767, 28499, 18751, 9333, 3514, 1001}; // numTaps = 15, L = 5
+// Generated using gaussfir(0.35, 1, 10) in MATLAB
+static q15_t GAUSSIAN_0_35_FILTER[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1001, 1942, 3514, 5930,
+                                      9333, 13699, 18751, 23938, 28499, 31644, 32767, 31644,
+                                      28499, 23938, 18751, 13699, 9333, 5930, 3514, 1942, 1001}; // numTaps = 30, L = 10
 const uint16_t GAUSSIAN_0_35_FILTER_PHASE_LEN = 3U; // phaseLength = numTaps/L
 
 const q15_t DSTAR_LEVEL0 = -841;
@@ -196,9 +198,9 @@ m_poLen(0U),
 m_poPtr(0U),
 m_txDelay(60U)       // 100ms
 {
-  ::memset(m_modState, 0x00U, 20U * sizeof(q15_t));
+  ::memset(m_modState, 0x00U, 15U * 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 +254,8 @@ 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 +264,11 @@ 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 +414,7 @@ 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 +429,7 @@ 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)

DStarTX.h

@@ -40,7 +40,7 @@ public:
 private:
   CSerialRB                        m_buffer;
   arm_fir_interpolate_instance_q15 m_modFilter;
-  q15_t                            m_modState[20U];    // blockSize + phaseLength - 1, 8 + 9 - 1 plus some spare
+  q15_t                            m_modState[15U];    // blockSize + phaseLength - 1, 8 + 3 - 1 plus some spare
   uint8_t                          m_poBuffer[600U];
   uint16_t                         m_poLen;
   uint16_t                         m_poPtr;

Globals.h

@@ -86,8 +86,8 @@ const uint8_t  MARK_NONE  = 0x00U;
 
 const uint16_t RX_BLOCK_SIZE = 2U;
 
-const uint16_t TX_RINGBUFFER_SIZE = 500U;
-const uint16_t RX_RINGBUFFER_SIZE = 600U;
+const uint16_t TX_RINGBUFFER_SIZE = 1000U;
+const uint16_t RX_RINGBUFFER_SIZE = 1200U;
 
 extern MMDVM_STATE m_modemState;
 

IO.cpp

@@ -23,12 +23,12 @@
 #include "IO.h"
 
 // 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}
+static q31_t   DC_FILTER[] = {1685306, 0, 1685306, 0, 2144113034, 0}; // {b0, 0, b1, b2, -a1, -a2}
 const uint32_t DC_FILTER_STAGES = 1U; // One Biquad stage
 
 // One symbol boxcar filter
-static q15_t   BOXCAR_FILTER[] = {12000, 12000, 12000, 12000, 12000, 0};
-const uint16_t BOXCAR_FILTER_LEN = 6U;
+static q15_t   BOXCAR_FILTER[] = {6000, 6000, 6000, 6000, 6000, 6000, 6000, 6000, 6000, 6000, 0, 0};
+const uint16_t BOXCAR_FILTER_LEN = 12U;
 
 const uint16_t DC_OFFSET = 2048U;
 
@@ -168,7 +168,7 @@ void CIO::process()
   m_ledCount++;
   if (m_started) {
     // Two seconds timeout
-    if (m_watchdog >= 48000U) {
+    if (m_watchdog >= 96000U) {
       if (m_modemState == STATE_DSTAR || m_modemState == STATE_DMR || m_modemState == STATE_YSF) {
         if (m_modemState == STATE_DMR && m_tx)
           dmrTX.setStart(false);
@@ -179,13 +179,13 @@ void CIO::process()
       m_watchdog = 0U;
     }
 
-    if (m_ledCount >= 24000U) {
+    if (m_ledCount >= 48000U) {
       m_ledCount = 0U;
       m_ledValue = !m_ledValue;
       setLEDInt(m_ledValue);
     }
   } else {
-    if (m_ledCount >= 240000U) {
+    if (m_ledCount >= 480000U) {
       m_ledCount = 0U;
       m_ledValue = !m_ledValue;
       setLEDInt(m_ledValue);

IODue.cpp

@@ -140,11 +140,11 @@ void CIO::startInt()
     TC_CMR_ACPA_CLEAR | TC_CMR_ACPC_CLEAR |
     TC_CMR_BCPB_CLEAR | TC_CMR_BCPC_CLEAR;
 #if defined(EXTERNAL_OSC)
-  t->TC_RC  = EXTERNAL_OSC / 24000;           // Counter resets on RC, so sets period in terms of the external clock
-  t->TC_RA  = EXTERNAL_OSC / 48000;           // Roughly square wave
+  t->TC_RC  = EXTERNAL_OSC / 48000;           // Counter resets on RC, so sets period in terms of the external clock
+  t->TC_RA  = EXTERNAL_OSC / 96000;           // Roughly square wave
 #else
-  t->TC_RC  = 1750;                           // Counter resets on RC, so sets period in terms of 42MHz internal clock
-  t->TC_RA  = 880;                            // Roughly square wave
+  t->TC_RC  = 875;                            // Counter resets on RC, so sets period in terms of 42MHz internal clock
+  t->TC_RA  = 438;                            // Roughly square wave
 #endif
   t->TC_CMR = (t->TC_CMR & 0xFFF0FFFF) | TC_CMR_ACPA_CLEAR | TC_CMR_ACPC_SET;  // Set clear and set from RA and RC compares
   t->TC_CCR = TC_CCR_CLKEN | TC_CCR_SWTRG;    // re-enable local clocking and switch to hardware trigger source.

IOSTM.cpp

@@ -573,7 +573,7 @@ EXT_CLK  PA15   input            CN11 Pin17
 const uint16_t DC_OFFSET = 2048U;
 
 // Sampling frequency
-#define SAMP_FREQ   24000
+#define SAMP_FREQ   48000
 
 extern "C" {
    void TIM2_IRQHandler() {

IOSTM_CMSIS.cpp

@@ -103,7 +103,7 @@ USART1_RXD PA10  input (AF)
 const uint16_t DC_OFFSET = 2048U;
 
 // Sampling frequency
-#define SAMP_FREQ   24000
+#define SAMP_FREQ   48000
 
 extern "C" {
   void TIM2_IRQHandler() {

IOTeensy.cpp

@@ -112,7 +112,7 @@ void CIO::startInt()
 #endif
 
 #if defined(EXTERNAL_OSC)
-  // Set ADC0 to trigger from the LPTMR at 24 kHz
+  // Set ADC0 to trigger from the LPTMR at 48 kHz
   SIM_SOPT7   = SIM_SOPT7_ADC0ALTTRGEN |                              // Enable ADC0 alternate trigger
                 SIM_SOPT7_ADC0TRGSEL(14);                             // Trigger ADC0 by LPTMR0
 
@@ -121,14 +121,14 @@ void CIO::startInt()
   SIM_SCGC5  |= SIM_SCGC5_LPTIMER;                                    // Enable Low Power Timer Access
   LPTMR0_CSR  = 0;                                                    // Disable
   LPTMR0_PSR  = LPTMR_PSR_PBYP;                                       // Bypass prescaler/filter
-  LPTMR0_CMR  = (EXTERNAL_OSC / 24000) - 1;                           // Frequency divided by CMR + 1
+  LPTMR0_CMR  = (EXTERNAL_OSC / 48000) - 1;                           // Frequency divided by CMR + 1
   LPTMR0_CSR  = LPTMR_CSR_TPS(2) |                                    // Pin: 0=CMP0, 1=xtal, 2=pin13
                 LPTMR_CSR_TMS;                                        // Mode Select, 0=timer, 1=counter
   LPTMR0_CSR |= LPTMR_CSR_TEN;                                        // Enable
 #else
-  // Setup PDB for ADC0 at 24 kHz
+  // Setup PDB for ADC0 at 48 kHz
   SIM_SCGC6  |= SIM_SCGC6_PDB;                                        // Enable PDB clock
-  PDB0_MOD    = (F_BUS / 24000) - 1;                                  // Timer period - 1
+  PDB0_MOD    = (F_BUS / 48000) - 1;                                  // Timer period - 1
   PDB0_IDLY   = 0;                                                    // Interrupt delay
   PDB0_CH0C1  = PDB_CHnC1_TOS | PDB_CHnC1_EN;                         // Enable pre-trigger for ADC0
   PDB0_SC     = PDB_SC_TRGSEL(15) | PDB_SC_PDBEN |                    // SW trigger, enable interrupts, continuous mode

P25Defines.h

@@ -19,7 +19,7 @@
 #if !defined(P25DEFINES_H)
 #define  P25DEFINES_H
 
-const unsigned int P25_RADIO_SYMBOL_LENGTH = 5U;      // At 24 kHz sample rate
+const unsigned int P25_RADIO_SYMBOL_LENGTH = 10U;      // At 48 kHz sample rate
 
 const unsigned int P25_HDR_FRAME_LENGTH_BYTES      = 99U;
 const unsigned int P25_HDR_FRAME_LENGTH_BITS       = P25_HDR_FRAME_LENGTH_BYTES * 8U;

P25TX.cpp

@@ -23,11 +23,15 @@
 
 #include "P25Defines.h"
 
-// Generated using rcosdesign(0.2, 8, 5, 'normal') in MATLAB
-// numTaps = 40, L = 5
-static q15_t RC_0_2_FILTER[] = {-897, -1636, -1840, -1278, 0, 1613, 2936, 3310, 2315, 0, -3011, -5627, -6580, -4839,
-                                0, 7482, 16311, 24651, 30607, 32767, 30607, 24651, 16311, 7482, 0, -4839, -6580, -5627,
-                               -3011, 0, 2315, 3310, 2936, 1613, 0, -1278, -1840, -1636, -897, 0}; // numTaps = 40, L = 5
+// Generated using rcosdesign(0.2, 8, 10, 'normal') in MATLAB
+static q15_t RC_0_2_FILTER[] = {-444, -897, -1311, -1636, -1825, -1840, -1659, -1278, -712, 0,
+                               800, 1613, 2354, 2936, 3277, 3310, 2994, 2315, 1296, 0, -1478,
+                               -3011, -4448, -5627, -6386, -6580, -6090, -4839, -2800, 0, 3474,
+                               7482, 11835, 16311, 20666, 24651, 28032, 30607, 32219, 32767,
+                               32219, 30607, 28032, 24651, 20666, 16311, 11835, 7482, 3474, 0,
+                               -2800, -4839, -6090, -6580, -6386, -5627, -4448, -3011, -1478,
+                               0, 1296, 2315, 2994, 3310, 3277, 2936, 2354, 1613, 800, 0, -712,
+                               -1278, -1659, -1840, -1825, -1636, -1311, -897, -444, 0}; // numTaps = 80, L = 10
 const uint16_t RC_0_2_FILTER_PHASE_LEN = 8U; // phaseLength = numTaps/L
 
 // Generated in MATLAB using the following commands, and then normalised for unity gain

SerialPort.cpp

@@ -73,9 +73,9 @@ const uint8_t MMDVM_DEBUG5       = 0xF5U;
 
 
 #if defined(EXTERNAL_OSC)
-#define DESCRIPTION              "MMDVM 20170501 TCXO (D-Star/DMR/System Fusion/P25/RSSI/CW Id)"
+#define DESCRIPTION              "MMDVM 20170501 TCXO 48kHz (D-Star/DMR/YSF/P25/RSSI/CW Id)"
 #else
-#define DESCRIPTION              "MMDVM 20170501 (D-Star/DMR/System Fusion/P25/RSSI/CW Id)"
+#define DESCRIPTION              "MMDVM 20170501 48kHz (D-Star/DMR/YSF/P25/RSSI/CW Id)"
 #endif
 
 #if defined(GITVERSION)
@@ -701,7 +701,7 @@ void CSerialPort::process()
     }
   }
 
-  if (io.getWatchdog() >= 48000U) {
+  if (io.getWatchdog() >= 96000U) {
     m_ptr = 0U;
     m_len = 0U;
   }

TODO.txt

@@ -0,0 +1,41 @@
+Jobs To Do
+----------
+
+Jobs Done
+---------
+
+1.  Boxcar coefficients
+2.  Symbols lengths for:
+	 D-Star
+	 DMR
+	 YSF
+	 P25
+3.  Sample ring buffer sizing
+	 RX
+	 TX
+4.  Hardware sample rates:
+	 Due
+	 STM32
+	 Teensy
+5.  DC Offset coefficients
+6.  TX Filters:
+	 D-Star
+	 DMR
+	 YSF
+	 P25
+7.  TX Filter workspaces and clearing:
+	 D-Star
+	 DMR
+	 YSF
+	 P25
+8.  CW Id sine wave, silence and construction
+9.  RX Filters
+10. RX Filter workspaces and clearing:
+	 D-Star
+	 DMR
+	 YSF
+	 P25
+11. TX symbols.
+12. DC Offset workspace and clearing.
+13. DMR magic numbers.
+14. Watchdog values.

YSFDefines.h

@@ -19,7 +19,7 @@
 #if !defined(YSFDEFINES_H)
 #define  YSFDEFINES_H
 
-const unsigned int YSF_RADIO_SYMBOL_LENGTH = 5U;      // At 24 kHz sample rate
+const unsigned int YSF_RADIO_SYMBOL_LENGTH = 10U;      // At 48 kHz sample rate
 
 const unsigned int YSF_FRAME_LENGTH_BYTES   = 120U;
 const unsigned int YSF_FRAME_LENGTH_BITS    = YSF_FRAME_LENGTH_BYTES * 8U;

YSFTX.cpp

@@ -23,10 +23,16 @@
 
 #include "YSFDefines.h"
 
-// Generated using rcosdesign(0.2, 8, 5, 'sqrt') in MATLAB
-static q15_t RRC_0_2_FILTER[] = {0, 0, 0, 0, 850, 219, -720, -1548, -1795, -1172, 237, 1927, 3120, 3073, 1447, -1431, -4544, -6442,
-                                 -5735, -1633, 5651, 14822, 23810, 30367, 32767, 30367, 23810, 14822, 5651, -1633, -5735, -6442,
-                                 -4544, -1431, 1447, 3073, 3120, 1927, 237, -1172, -1795, -1548, -720, 219, 850}; // numTaps = 45, L = 5
+// Generated using rcosdesign(0.2, 8, 10, 'sqrt') in MATLAB
+static q15_t RRC_0_2_FILTER[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 850, 592, 219, -234, -720, -1179,
+                                -1548, -1769, -1795, -1597, -1172, -544, 237, 1092, 1927, 2637,
+                                3120, 3286, 3073, 2454, 1447, 116, -1431, -3043, -4544, -5739,
+                                -6442, -6483, -5735, -4121, -1633, 1669, 5651, 10118, 14822,
+                                19484, 23810, 27520, 30367, 32156, 32767, 32156, 30367, 27520,
+                                23810, 19484, 14822, 10118, 5651, 1669, -1633, -4121, -5735,
+                                -6483, -6442, -5739, -4544, -3043, -1431, 116, 1447, 2454,
+                                3073, 3286, 3120, 2637, 1927, 1092, 237, -544, -1172, -1597,
+                                -1795, -1769, -1548, -1179, -720, -234, 219, 592, 850}; // numTaps = 90, L = 10
 const uint16_t RRC_0_2_FILTER_PHASE_LEN = 9U; // phaseLength = numTaps/L
 
 const q15_t YSF_LEVELA_HI =  1893;