mirror of
https://github.com/f4exb/sdrangel.git
synced 2024-11-07 17:16:02 -05:00
70 lines
1.1 KiB
C
70 lines
1.1 KiB
C
|
/*
|
||
|
|
LDPC SISO encoder
|
||
|
|
|
||
|
|
Copyright 2018 Ahmet Inan <xdsopl@gmail.com>
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef ENCODER_HH
|
||
|
|
#define ENCODER_HH
|
||
|
|
|
||
|
|
#include "ldpc.h"
|
||
|
|
|
||
|
|
namespace ldpctool {
|
||
|
|
|
||
|
|
template <typename TYPE>
|
||
|
|
class LDPCEncoder
|
||
|
|
{
|
||
|
|
LDPCInterface *ldpc;
|
||
|
|
int N, K, R;
|
||
|
|
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 ldpc;
|
||
|
|
initialized = true;
|
||
|
|
ldpc = it->clone();
|
||
|
|
N = ldpc->code_len();
|
||
|
|
K = ldpc->data_len();
|
||
|
|
R = N - K;
|
||
|
|
}
|
||
|
|
void operator()(TYPE *data, TYPE *parity)
|
||
|
|
{
|
||
|
|
for (int i = 0; i < R; ++i)
|
||
|
|
parity[i] = one();
|
||
|
|
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];
|
||
|
|
parity[i] = sign(parity[i], data[j]);
|
||
|
|
}
|
||
|
|
ldpc->next_bit();
|
||
|
|
}
|
||
|
|
for (int i = 1; i < R; ++i)
|
||
|
|
parity[i] = sign(parity[i], parity[i-1]);
|
||
|
|
}
|
||
|
|
~LDPCEncoder()
|
||
|
|
{
|
||
|
|
if (initialized)
|
||
|
|
delete ldpc;
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
} // namespace ldpctool
|
||
|
|
|
||
|
|
#endif
|