mirror of
https://github.com/f4exb/sdrangel.git
synced 2024-12-02 04:55:23 -05:00
83 lines
1.3 KiB
C
83 lines
1.3 KiB
C
|
/*
|
||
|
|
LDPC SISO encoder v2
|
||
|
|
|
||
|
|
Copyright 2018 Ahmet Inan <xdsopl@gmail.com>
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef ENCODER_HH
|
||
|
|
#define ENCODER_HH
|
||
|
|
|
||
|
|
#include "ldpc.h"
|
||
|
|
|
||
|
|
namespace ldpctool {
|
||
|
|
|
||
|
|
template <typename TYPE>
|
||
|
|
class LDPCEncoder
|
||
|
|
{
|
||
|
|
uint16_t *pos;
|
||
|
|
uint8_t *cnc;
|
||
|
|
int R, CNL;
|
||
|
|
bool initialized;
|
||
|
|
|
||
|
|
TYPE one()
|
||
|
|
{
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
TYPE sign(TYPE a, TYPE b)
|
||
|
|
{
|
||
|
|
return b < TYPE(0) ? -a : b > TYPE(0) ? a : TYPE(0);
|
||
|
|
}
|
||
|
|
public:
|
||
|
|
LDPCEncoder() : initialized(false)
|
||
|
|
{
|
||
|
|
}
|
||
|
|
void init(LDPCInterface *it)
|
||
|
|
{
|
||
|
|
if (initialized) {
|
||
|
|
delete[] pos;
|
||
|
|
delete[] cnc;
|
||
|
|
}
|
||
|
|
initialized = true;
|
||
|
|
LDPCInterface *ldpc = it->clone();
|
||
|
|
int N = ldpc->code_len();
|
||
|
|
int K = ldpc->data_len();
|
||
|
|
R = N - K;
|
||
|
|
CNL = ldpc->links_max_cn() - 2;
|
||
|
|
pos = new uint16_t[R * CNL];
|
||
|
|
cnc = new uint8_t[R];
|
||
|
|
for (int i = 0; i < R; ++i)
|
||
|
|
cnc[i] = 0;
|
||
|
|
ldpc->first_bit();
|
||
|
|
for (int j = 0; j < K; ++j) {
|
||
|
|
int *acc_pos = ldpc->acc_pos();
|
||
|
|
int bit_deg = ldpc->bit_deg();
|
||
|
|
for (int n = 0; n < bit_deg; ++n) {
|
||
|
|
int i = acc_pos[n];
|
||
|
|
pos[CNL*i+cnc[i]++] = j;
|
||
|
|
}
|
||
|
|
ldpc->next_bit();
|
||
|
|
}
|
||
|
|
delete ldpc;
|
||
|
|
}
|
||
|
|
void operator()(TYPE *data, TYPE *parity)
|
||
|
|
{
|
||
|
|
TYPE tmp = one();
|
||
|
|
for (int i = 0; i < R; ++i) {
|
||
|
|
for (int j = 0; j < cnc[i]; ++j)
|
||
|
|
tmp = sign(tmp, data[pos[CNL*i+j]]);
|
||
|
|
parity[i] = tmp;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
~LDPCEncoder()
|
||
|
|
{
|
||
|
|
if (initialized) {
|
||
|
|
delete[] pos;
|
||
|
|
delete[] cnc;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
} // namespace ldpctool
|
||
|
|
|
||
|
|
#endif
|