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First go at VW mode IMBE FEC.

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This commit is contained in:
Jonathan Naylor
2016-04-19 07:45:49 +01:00
parent b560594cac
commit 38dc134982
5 changed files with 199 additions and 107 deletions
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168
AMBEFEC.cpp
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@@ -17,6 +17,7 @@
*/
#include "Golay24128.h"
#include "Hamming.h"
#include "AMBEFEC.h"
#include <cstdio>
@@ -453,6 +454,15 @@ const unsigned int DSTAR_B_TABLE[] = {2U, 8U, 14U, 20U, 26U, 32U, 38U, 44U, 50U
const unsigned int DSTAR_C_TABLE[] = {4U, 10U, 16U, 22U, 28U, 34U, 40U, 46U, 52U, 58U, 64U, 70U,
5U, 11U, 17U, 23U, 29U, 35U, 41U, 47U, 53U, 59U, 65U, 71U};
const unsigned int IMBE_INTERLEAVE[] = {
0, 7, 12, 19, 24, 31, 36, 43, 48, 55, 60, 67, 72, 79, 84, 91, 96, 103, 108, 115, 120, 127, 132, 139,
1, 6, 13, 18, 25, 30, 37, 42, 49, 54, 61, 66, 73, 78, 85, 90, 97, 102, 109, 114, 121, 126, 133, 138,
2, 9, 14, 21, 26, 33, 38, 45, 50, 57, 62, 69, 74, 81, 86, 93, 98, 105, 110, 117, 122, 129, 134, 141,
3, 8, 15, 20, 27, 32, 39, 44, 51, 56, 63, 68, 75, 80, 87, 92, 99, 104, 111, 116, 123, 128, 135, 140,
4, 11, 16, 23, 28, 35, 40, 47, 52, 59, 64, 71, 76, 83, 88, 95, 100, 107, 112, 119, 124, 131, 136, 143,
5, 10, 17, 22, 29, 34, 41, 46, 53, 58, 65, 70, 77, 82, 89, 94, 101, 106, 113, 118, 125, 130, 137, 142
};
CAMBEFEC::CAMBEFEC()
{
}
@@ -583,50 +593,132 @@ unsigned int CAMBEFEC::regenerateDStar(unsigned char* bytes) const
return errors;
}
unsigned int CAMBEFEC::regenerateYSF1(unsigned char* bytes) const
unsigned int CAMBEFEC::regenerateYSF3(unsigned char* bytes) const
{
assert(bytes != NULL);
unsigned int errors = 0U;
unsigned int offset = 72U;
for (unsigned int j = 0U; j < 5U; j++, offset += 144U) {
unsigned int a = 0U;
unsigned int b = 0U;
unsigned int c = 0U;
bool temp[144U];
unsigned int MASK = 0x800000U;
for (unsigned int i = 0U; i < 24U; i++) {
unsigned int aPos = DMR_A_TABLE[i] + offset;
unsigned int bPos = DMR_B_TABLE[i] + offset;
unsigned int cPos = DMR_C_TABLE[i] + offset;
if (READ_BIT(bytes, aPos))
a |= MASK;
if (READ_BIT(bytes, bPos))
b |= MASK;
if (READ_BIT(bytes, cPos))
c |= MASK;
MASK >>= 1;
}
errors += regenerate(a, b, c, true);
MASK = 0x800000U;
for (unsigned int i = 0U; i < 24U; i++) {
unsigned int aPos = DMR_A_TABLE[i] + offset;
unsigned int bPos = DMR_B_TABLE[i] + offset;
unsigned int cPos = DMR_C_TABLE[i] + offset;
WRITE_BIT(bytes, aPos, a & MASK);
WRITE_BIT(bytes, bPos, b & MASK);
WRITE_BIT(bytes, cPos, c & MASK);
MASK >>= 1;
}
// De-interleave
for (unsigned int i = 0U; i < 144U; i++) {
unsigned int n = IMBE_INTERLEAVE[i];
temp[i] = READ_BIT(bytes, n);
}
return errors;
// now ..
// 12 voice bits 0
// 11 golay bits 12
//
// 12 voice bits 23
// 11 golay bits 35
//
// 12 voice bits 46
// 11 golay bits 58
//
// 12 voice bits 69
// 11 golay bits 81
//
// 11 voice bits 92
// 4 hamming bits 103
//
// 11 voice bits 107
// 4 hamming bits 118
//
// 11 voice bits 122
// 4 hamming bits 133
//
// 7 voice bits 137
// De-Whiten some bits
unsigned int prn = 0x00U;
for (int i = 0U; i < 12U; i++)
prn = (prn << 1) | (temp[i] & 1);
prn <<= 4;
for (unsigned int i = 23U; i < 137U; i++) {
prn = (unsigned short)((173 * prn) + 13849);
temp[i] ^= (prn >> 15) & 1;
}
// Check/Fix FEC
bool* bit = temp;
// c0
unsigned int g1 = 0U;
for (unsigned int i = 0U; i < 23U; i++)
g1 = (g1 << 1) | (bit[i] & 1);
unsigned int g3 = CGolay24128::decode23127(g1);
unsigned int g2 = CGolay24128::encode23127(g3);
for (int i = 23; i >= 0; i--) {
bit[i] = g2 & 1;
g2 >>= 1;
}
bit += 23U;
// c1
g1 = 0U;
for (unsigned int i = 0U; i < 23U; i++)
g1 = (g1 << 1) | (bit[i] & 1);
g3 = CGolay24128::decode23127(g1);
g2 = CGolay24128::encode23127(g3);
for (int i = 23; i >= 0; i--) {
bit[i] = g2 & 1;
g2 >>= 1;
}
bit += 23U;
// c2
g1 = 0;
for (int i = 0; i < 23; i++)
g1 = (g1 << 1) | (bit[i] & 1);
g3 = CGolay24128::decode23127(g1);
g2 = CGolay24128::encode23127(g3);
for (int i = 23; i >= 0; i--) {
bit[i] = g2 & 1;
g2 >>= 1;
}
bit += 23U;
// c3
g1 = 0U;
for (int i = 0U; i < 23U; i++)
g1 = (g1 << 1) | (bit[i] & 1);
g3 = CGolay24128::decode23127(g1);
g2 = CGolay24128::encode23127(g3);
for (int i = 23; i >= 0; i--) {
bit[i] = g2 & 1;
g2 >>= 1;
}
bit += 23U;
// c4
CHamming::decode15113_1(bit);
bit += 15U;
// c5
CHamming::decode15113_1(bit);
bit += 15U;
// c6
CHamming::decode15113_1(bit);
// Whiten some bits
prn = 0x00U;
for (unsigned int i = 0U; i < 12U; i++)
prn = (prn << 1) | (temp[i] & 1);
prn <<= 4;
for (unsigned int i = 23U; i < 137U; i++) {
prn = (unsigned short)((173 * prn) + 13849);
temp[i] ^= (prn >> 15) & 1;
}
// Interleave
for (unsigned int i = 0U; i < 144U; i++) {
unsigned int n = IMBE_INTERLEAVE[i];
WRITE_BIT(bytes, n, temp[i]);
}
return 0U;
}
unsigned int CAMBEFEC::regenerate(unsigned int& a, unsigned int& b, unsigned int& c, bool b23) const