Crash_Override/MMDVMHost-Private
1
0
Fork 0
Code Issues Pull requests Packages Projects Releases Wiki Activity

Merge pull request #378 from juribeparada/nxdn

Browse source 
More Viterbi decoder work for NXDN
This commit is contained in:
Jonathan Naylor 2018-02-01 19:09:38 +00:00 committed by GitHub
parent b69d3d247c d4fbc8f7ec
commit 121af6278b
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
4 changed files with 34 additions and 31 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

17
NXDNConvolution.cpp
View file

@ -27,12 +27,12 @@ const unsigned char BIT_MASK_TABLE[] = {0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U
#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])
#define READ_BIT1(p,i) (p[(i)>>3] & BIT_MASK_TABLE[(i)&7])
const uint8_t BRANCH_TABLE1[] = {0U, 0U, 0U, 0U, 1U, 1U, 1U, 1U};
const uint8_t BRANCH_TABLE2[] = {0U, 1U, 1U, 0U, 0U, 1U, 1U, 0U};
const uint8_t BRANCH_TABLE1[] = {0U, 0U, 0U, 0U, 2U, 2U, 2U, 2U};
const uint8_t BRANCH_TABLE2[] = {0U, 2U, 2U, 0U, 0U, 2U, 2U, 0U};
const unsigned int NUM_OF_STATES_D2 = 8U;
const unsigned int NUM_OF_STATES = 16U;
const uint32_t M = 2U;
const uint32_t M = 4U;
const unsigned int K = 5U;
CNXDNConvolution::CNXDNConvolution() :
@ -72,16 +72,7 @@ void CNXDNConvolution::decode(uint8_t s0, uint8_t s1)
for (uint8_t i = 0U; i < NUM_OF_STATES_D2; i++) {
uint8_t j = i * 2U;
uint16_t metric0 = 0;
uint16_t metric1 = 0;
if (s0 != 99U)
metric0 = (BRANCH_TABLE1[i] ^ s0);
if (s1 != 99U)
metric1 = (BRANCH_TABLE2[i] ^ s1);
uint16_t metric = metric0 + metric1;
uint16_t metric = abs(BRANCH_TABLE1[i] - s0) + abs(BRANCH_TABLE2[i] - s1);
uint16_t m0 = m_oldMetrics[i] + metric;
uint16_t m1 = m_oldMetrics[i + NUM_OF_STATES_D2] + (M - metric);

14
NXDNFACCH1.cpp
View file

@ -84,32 +84,36 @@ bool CNXDNFACCH1::decode(const unsigned char* data, unsigned int offset)
// CUtils::dump("NXDN, FACCH1 de-interleaved", temp1, 18U);
uint8_t temp2[192U];
uint8_t temp2[210U];
unsigned int n = 0U;
unsigned int index = 0U;
for (unsigned int i = 0U; i < NXDN_FACCH1_LENGTH_BITS; i++) {
if (n == PUNCTURE_LIST[index]) {
temp2[n++] = 99U;
temp2[n++] = 1U;
index++;
}
bool b = READ_BIT1(temp1, i);
temp2[n++] = b ? 1U : 0U;
temp2[n++] = b ? 2U : 0U;
}
for (unsigned int i = 0U; i < 8U; i++) {
temp2[n++] = 0U;
}
CNXDNConvolution conv;
conv.start();
n = 0U;
for (unsigned int i = 0U; i < 96U; i++) {
for (unsigned int i = 0U; i < 100U; i++) {
uint8_t s0 = temp2[n++];
uint8_t s1 = temp2[n++];
conv.decode(s0, s1);
}
conv.chainback(m_data, 92U);
conv.chainback(m_data, 96U);
CUtils::dump("NXDN, FACCH1 decoded", m_data, 12U);

14
NXDNSACCH.cpp
View file

@ -77,32 +77,36 @@ bool CNXDNSACCH::decode(const unsigned char* data)
// CUtils::dump("NXDN, SACCH de-interleaved", temp1, 8U);
uint8_t temp2[72U];
uint8_t temp2[90U];
unsigned int n = 0U;
unsigned int index = 0U;
for (unsigned int i = 0U; i < NXDN_SACCH_LENGTH_BITS; i++) {
if (n == PUNCTURE_LIST[index]) {
temp2[n++] = 99U;
temp2[n++] = 1U;
index++;
}
bool b = READ_BIT1(temp1, i);
temp2[n++] = b ? 1U : 0U;
temp2[n++] = b ? 2U : 0U;
}
for (unsigned int i = 0U; i < 8U; i++) {
temp2[n++] = 0U;
}
CNXDNConvolution conv;
conv.start();
n = 0U;
for (unsigned int i = 0U; i < 36U; i++) {
for (unsigned int i = 0U; i < 40U; i++) {
uint8_t s0 = temp2[n++];
uint8_t s1 = temp2[n++];
conv.decode(s0, s1);
}
conv.chainback(m_data, 32U);
conv.chainback(m_data, 36U);
CUtils::dump("NXDN, SACCH decoded", m_data, 4U);

20
NXDNUDCH.cpp
View file

@ -74,14 +74,14 @@ const unsigned char BIT_MASK_TABLE[] = { 0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04
CNXDNUDCH::CNXDNUDCH(const CNXDNUDCH& udch) :
m_data(NULL)
{
m_data = new unsigned char[23U + 2U];
::memcpy(m_data, udch.m_data, 23U + 2U);
m_data = new unsigned char[23U + 3U];
::memcpy(m_data, udch.m_data, 23U + 3U);
}
CNXDNUDCH::CNXDNUDCH() :
m_data(NULL)
{
m_data = new unsigned char[23U + 2U];
m_data = new unsigned char[23U + 3U];
}
CNXDNUDCH::~CNXDNUDCH()
@ -105,32 +105,36 @@ bool CNXDNUDCH::decode(const unsigned char* data)
CUtils::dump("NXDN, UDCH/FACCH2 de-interleaved", temp1, 44U);
uint8_t temp2[406U];
uint8_t temp2[420U];
unsigned int n = 0U;
unsigned int index = 0U;
for (unsigned int i = 0U; i < NXDN_FACCH2_LENGTH_BITS; i++) {
if (n == PUNCTURE_LIST[index]) {
temp2[n++] = 99U;
temp2[n++] = 1U;
index++;
}
bool b = READ_BIT1(temp1, i);
temp2[n++] = b ? 1U : 0U;
temp2[n++] = b ? 2U : 0U;
}
for (unsigned int i = 0U; i < 8U; i++) {
temp2[n++] = 0U;
}
CNXDNConvolution conv;
conv.start();
n = 0U;
for (unsigned int i = 0U; i < 203U; i++) {
for (unsigned int i = 0U; i < 207U; i++) {
uint8_t s0 = temp2[n++];
uint8_t s1 = temp2[n++];
conv.decode(s0, s1);
}
conv.chainback(m_data, 199U);
conv.chainback(m_data, 203U);
CUtils::dump("NXDN, UDCH/FACCH2 decoded", m_data, 25U);