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Make the D-Star demodulator stiffer when locked.

48kHz
Jonathan Naylor 2016-03-21 22:03:00 +00:00
parent 89d9dd9a7b
commit 96091c8424
2 changed files with 22 additions and 10 deletions
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28
DStarRX.cpp
View File

@ -25,9 +25,10 @@
const unsigned int BUFFER_LENGTH = 200U; const unsigned int BUFFER_LENGTH = 200U;
const uint32_t PLLMAX = 0x10000U; const uint32_t PLLMAX = 0x10000U;
const uint32_t PLLINC = PLLMAX / DSTAR_RADIO_BIT_LENGTH; const uint32_t PLLINC = PLLMAX / DSTAR_RADIO_BIT_LENGTH;
const uint32_t INC = PLLINC / 32U; const uint32_t INC_LOCK = PLLINC / 64U;
const uint32_t INC_UNLOCK = PLLINC / 32U;
const unsigned int MAX_SYNC_BITS = 50U * DSTAR_DATA_LENGTH_BITS; const unsigned int MAX_SYNC_BITS = 50U * DSTAR_DATA_LENGTH_BITS;
@ -243,6 +244,7 @@ const uint16_t CCITT_TABLE[] = {
CDStarRX::CDStarRX() : CDStarRX::CDStarRX() :
m_pll(0U), m_pll(0U),
m_prev(false), m_prev(false),
m_inc(INC_UNLOCK),
m_rxState(DSRXS_NONE), m_rxState(DSRXS_NONE),
m_patternBuffer(0x00U), m_patternBuffer(0x00U),
m_rxBuffer(), m_rxBuffer(),
@ -264,6 +266,7 @@ void CDStarRX::reset()
{ {
m_pll = 0U; m_pll = 0U;
m_prev = false; m_prev = false;
m_inc = INC_UNLOCK;
m_rxState = DSRXS_NONE; m_rxState = DSRXS_NONE;
m_patternBuffer = 0x00U; m_patternBuffer = 0x00U;
m_rxBufferBits = 0U; m_rxBufferBits = 0U;
@ -280,9 +283,9 @@ void CDStarRX::samples(const q15_t* samples, uint8_t length)
if (bit != m_prev) { if (bit != m_prev) {
if (m_pll < (PLLMAX / 2U)) if (m_pll < (PLLMAX / 2U))
m_pll += INC; m_pll += m_inc;
else else
m_pll -= INC; m_pll -= m_inc;
} }
m_prev = bit; m_prev = bit;
@ -333,7 +336,7 @@ void CDStarRX::processNone(bool bit)
// Exact matching of the data sync bit sequence // Exact matching of the data sync bit sequence
if (countBits32((m_patternBuffer & DATA_SYNC_MASK) ^ DATA_SYNC_DATA) == 0U) { if (countBits32((m_patternBuffer & DATA_SYNC_MASK) ^ DATA_SYNC_DATA) == 0U) {
DEBUG1("DStarRX: found data sync in None"); DEBUG1("DStarRX: found data sync in None");
io.setDecode(true); locked(true);
#if defined(WANT_DEBUG) #if defined(WANT_DEBUG)
q15_t min = 16000; q15_t min = 16000;
@ -373,7 +376,7 @@ void CDStarRX::processHeader(bool bit)
unsigned char header[DSTAR_HEADER_LENGTH_BYTES]; unsigned char header[DSTAR_HEADER_LENGTH_BYTES];
bool ok = rxHeader(m_rxBuffer, header); bool ok = rxHeader(m_rxBuffer, header);
if (ok) { if (ok) {
io.setDecode(true); locked(true);
serial.writeDStarHeader(header, DSTAR_HEADER_LENGTH_BYTES); serial.writeDStarHeader(header, DSTAR_HEADER_LENGTH_BYTES);
@ -401,7 +404,7 @@ void CDStarRX::processData(bool bit)
// Fuzzy matching of the end frame sequences // Fuzzy matching of the end frame sequences
if (countBits32((m_patternBuffer & END_SYNC_MASK) ^ END_SYNC_DATA) <= END_SYNC_ERRS) { if (countBits32((m_patternBuffer & END_SYNC_MASK) ^ END_SYNC_DATA) <= END_SYNC_ERRS) {
DEBUG1("DStarRX: Found end sync in Data"); DEBUG1("DStarRX: Found end sync in Data");
io.setDecode(false); locked(false);
serial.writeDStarEOT(); serial.writeDStarEOT();
@ -440,7 +443,7 @@ void CDStarRX::processData(bool bit)
m_dataBits--; m_dataBits--;
if (m_dataBits == 0U) { if (m_dataBits == 0U) {
DEBUG1("DStarRX: data sync timed out, lost lock"); DEBUG1("DStarRX: data sync timed out, lost lock");
io.setDecode(false); locked(false);
serial.writeDStarLost(); serial.writeDStarLost();
@ -693,3 +696,10 @@ bool CDStarRX::checksum(const uint8_t* header) const
return crc8[0U] == header[DSTAR_HEADER_LENGTH_BYTES - 2U] && crc8[1U] == header[DSTAR_HEADER_LENGTH_BYTES - 1U]; return crc8[0U] == header[DSTAR_HEADER_LENGTH_BYTES - 2U] && crc8[1U] == header[DSTAR_HEADER_LENGTH_BYTES - 1U];
} }
void CDStarRX::locked(bool lock)
{
io.setDecode(lock);
m_inc = lock ? INC_LOCK : INC_UNLOCK;
}

4
DStarRX.h
View File

@ -1,5 +1,5 @@
/* /*
* Copyright (C) 2015 by Jonathan Naylor G4KLX * Copyright (C) 2015,2016 by Jonathan Naylor G4KLX
* *
* This program is free software; you can redistribute it and/or modify * 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 * it under the terms of the GNU General Public License as published by
@ -39,6 +39,7 @@ public:
private: private:
uint32_t m_pll; uint32_t m_pll;
bool m_prev; bool m_prev;
uint32_t m_inc;
DSRX_STATE m_rxState; DSRX_STATE m_rxState;
uint32_t m_patternBuffer; uint32_t m_patternBuffer;
uint8_t m_rxBuffer[100U]; uint8_t m_rxBuffer[100U];
@ -62,6 +63,7 @@ private:
void viterbiDecode(int* data); void viterbiDecode(int* data);
void traceBack(); void traceBack();
bool checksum(const uint8_t* header) const; bool checksum(const uint8_t* header) const;
void locked(bool lock);
}; };
#endif #endif