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EMB correlation, work in progress.

48kHz
Jonathan Naylor 2016-08-31 08:15:06 +01:00
parent cf5f960dd1
commit 2e2acd30fa
3 changed files with 107 additions and 29 deletions
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126
DMRDMORX.cpp
View File

@ -22,6 +22,7 @@
#include "Globals.h"
#include "DMRDMORX.h"
#include "DMRSlotType.h"
#include "DMREMB.h"
#include "Utils.h"
const q15_t SCALING_FACTOR = 19505; // Q15(0.60)
@ -60,7 +61,8 @@ m_state(DMORXS_NONE),
m_n(0U),
m_type(0U),
m_rssiCount(0U),
m_rssi(0U)
m_rssi(0U),
m_embs()
{
}
@ -133,14 +135,14 @@ bool CDMRDMORX::processSample(q15_t sample)
if (m_dataPtr >= min && m_dataPtr <= max)
correlateSync(false);
// if (m_dataPtr == max1 && m_control == CONTROL_NONE)
// correlateEMB();
if (m_dataPtr == max1 && m_control == CONTROL_NONE)
correlateEMB();
} else {
if (m_dataPtr >= min || m_dataPtr <= max)
correlateSync(false);
// if (m_dataPtr == max1 && m_control == CONTROL_NONE)
// correlateEMB();
if (m_dataPtr == max1 && m_control == CONTROL_NONE)
correlateEMB();
}
}
@ -415,27 +417,60 @@ void CDMRDMORX::correlateEMB()
if (ptr >= DMO_BUFFER_LENGTH_SAMPLES)
ptr -= DMO_BUFFER_LENGTH_SAMPLES;
q15_t centre = (m_centre[0U] + m_centre[1U] + m_centre[2U] + m_centre[3U]) >> 2;
q15_t threshold = (m_threshold[0U] + m_threshold[1U] + m_threshold[2U] + m_threshold[3U]) >> 2;
q15_t centre = (m_centre[0U] + m_centre[1U] + m_centre[2U] + m_centre[3U]) >> 2;
bool correct[3U] = {false, false, false};
q31_t corr[3U];
for (uint8_t i = 0U; i < 3U; i++) {
uint8_t emb[1U];
samplesToBits(ptr, DMR_EMB_LENGTH_SYMBOLS / 2U, emb, 0U, centre, threshold);
uint16_t ptr1 = ptr;
uint16_t ptr2 = ptr + DMR_EMB_LENGTH_SAMPLES / 2U + DMR_EMBSIG_LENGTH_SAMPLES;
uint8_t cc = (emb[0U] & 0xF0U) >> 4;
uint8_t lcss = (emb[0U] & 0x06U) >> 1;
if (ptr2 >= DMO_BUFFER_LENGTH_SAMPLES)
ptr2 -= DMO_BUFFER_LENGTH_SAMPLES;
if (cc == m_colorCode && ((m_n == 0U && lcss == 1U) ||
(m_n == 1U && lcss == 3U) ||
(m_n == 2U && lcss == 3U) ||
(m_n == 3U && lcss == 2U) ||
(m_n == 4U && lcss == 0U))) {
correct[i] = true;
int16_t diff = m_syncPtr - ptr;
DEBUG4("DMRDMORX: ptr/emb/diff", ptr, cc, diff);
uint8_t pi = (emb[0U] & 0x08U) >> 3;
DEBUG4("DMRDMORX: pi/lcss/n", pi, lcss, m_n);
corr[i] = 0;
uint16_t emb1 = m_embs[m_n].part1;
uint16_t emb2 = m_embs[m_n].part2;
for (uint8_t j = 0U; j < 4U; j++) {
q15_t sample1 = m_buffer[ptr1] - centre;
q15_t sample2 = m_buffer[ptr2] - centre;
switch (emb1 & 0xC0U) {
case 0xC0U: corr[i] += (sample1 + sample1 + sample1); break;
case 0x80U: corr[i] += (sample1); break;
case 0x40U: corr[i] -= (sample1 + sample1 + sample1); break;
default: corr[i] -= (sample1); break;
}
switch (emb2 & 0xC0U) {
case 0xC0U: corr[i] += (sample2 + sample2 + sample2); break;
case 0x80U: corr[i] += (sample2); break;
case 0x40U: corr[i] -= (sample2 + sample2 + sample2); break;
default: corr[i] -= (sample2); break;
}
// uint8_t emb1[1U];
// samplesToBits(ptr1, DMR_EMB_LENGTH_SYMBOLS / 2U, emb1, 0U, centre, threshold);
// uint8_t emb2[1U];
// samplesToBits(ptr2, DMR_EMB_LENGTH_SYMBOLS / 2U, emb2, 0U, centre, threshold);
// errs[i] = countBits8(emb1[0U] ^ m_embs[m_n].part1) + countBits8(emb2[0U] ^ m_embs[m_n].part2);
// if (errs[i] < lowest)
// lowest = errs[i];
// DEBUG3("DMRDMORX: ptr/errs", ptr1, errs[i]);
emb1 <<= 2;
emb2 <<= 2;
ptr1 += DMR_RADIO_SYMBOL_LENGTH;
if (ptr1 >= DMO_BUFFER_LENGTH_SAMPLES)
ptr1 -= DMO_BUFFER_LENGTH_SAMPLES;
ptr2 += DMR_RADIO_SYMBOL_LENGTH;
if (ptr2 >= DMO_BUFFER_LENGTH_SAMPLES)
ptr2 -= DMO_BUFFER_LENGTH_SAMPLES;
}
ptr++;
@ -443,17 +478,30 @@ void CDMRDMORX::correlateEMB()
ptr -= DMO_BUFFER_LENGTH_SAMPLES;
}
if (correct[1U]) {
// Prefer the status quo
DEBUG4("DMRDMORX: -1/0/+1", corr[0U], corr[1], corr[2]);
// None of them are very good, don't use
// if (lowest > MAX_EMB_BITS_ERRS)
// return;
// if (errs[2U] == lowest) {
// // Prefer the status quo
// return;
// } else if (errs[1U] == lowest) {
// // m_syncPtr--
// m_syncPtr += DMO_BUFFER_LENGTH_SAMPLES - 1U;
// } else {
// m_syncPtr++;
// }
if (corr[1U] > corr[0U] && corr[1U] > corr[2U]) {
// Nothing has changed
return;
} else if (correct[0U]) {
} else if (corr[0U] > corr[1U] && corr[0U] > corr[2U]) {
// m_syncPtr--
m_syncPtr += DMO_BUFFER_LENGTH_SAMPLES - 1U;
} else if (correct[2U]) {
m_syncPtr++;
} else {
// No match, don't change anything
return;
m_syncPtr++;
}
if (m_syncPtr >= DMO_BUFFER_LENGTH_SAMPLES)
@ -506,5 +554,25 @@ void CDMRDMORX::samplesToBits(uint16_t start, uint8_t count, uint8_t* buffer, ui
void CDMRDMORX::setColorCode(uint8_t colorCode)
{
m_colorCode = colorCode;
// Build table of EMB values
uint16_t emb = CDMREMB::emb(colorCode, false, 1U);
m_embs[0U].part1 = (emb >> 8) & 0xFFU;
m_embs[0U].part2 = (emb >> 0) & 0xFFU;
emb = CDMREMB::emb(colorCode, false, 3U);
m_embs[1U].part1 = (emb >> 8) & 0xFFU;
m_embs[1U].part2 = (emb >> 0) & 0xFFU;
m_embs[2U].part1 = m_embs[1U].part1;
m_embs[2U].part2 = m_embs[1U].part2;
emb = CDMREMB::emb(colorCode, false, 2U);
m_embs[3U].part1 = (emb >> 8) & 0xFFU;
m_embs[3U].part2 = (emb >> 0) & 0xFFU;
emb = CDMREMB::emb(colorCode, false, 0U);
m_embs[4U].part1 = (emb >> 8) & 0xFFU;
m_embs[4U].part2 = (emb >> 0) & 0xFFU;
}

6
DMRDMORX.h
View File

@ -30,6 +30,11 @@ enum DMORX_STATE {
DMORXS_DATA
};
struct EMBList {
uint8_t part1;
uint8_t part2;
};
class CDMRDMORX {
public:
CDMRDMORX();
@ -60,6 +65,7 @@ private:
uint8_t m_type;
uint16_t m_rssiCount;
uint16_t m_rssi;
EMBList m_embs[5U];
bool processSample(q15_t sample);
void correlateSync(bool first);

4
DMRDefines.h
View File

@ -35,6 +35,10 @@ const unsigned int DMR_EMB_LENGTH_BITS = 16U;
const unsigned int DMR_EMB_LENGTH_SYMBOLS = 8U;
const unsigned int DMR_EMB_LENGTH_SAMPLES = DMR_EMB_LENGTH_SYMBOLS * DMR_RADIO_SYMBOL_LENGTH;
const unsigned int DMR_EMBSIG_LENGTH_BITS = 32U;
const unsigned int DMR_EMBSIG_LENGTH_SYMBOLS = 16U;
const unsigned int DMR_EMBSIG_LENGTH_SAMPLES = DMR_EMBSIG_LENGTH_SYMBOLS * DMR_RADIO_SYMBOL_LENGTH;
const unsigned int DMR_SLOT_TYPE_LENGTH_BITS = 20U;
const unsigned int DMR_SLOT_TYPE_LENGTH_SYMBOLS = 10U;
const unsigned int DMR_SLOT_TYPE_LENGTH_SAMPLES = DMR_SLOT_TYPE_LENGTH_SYMBOLS * DMR_RADIO_SYMBOL_LENGTH;