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#include "ccsds_ldpc.h"
#include <cstdlib>
#include <cmath>
#include <cstring>
#include "common/dsp/buffer.h"
#include "make_ccsds.h"
#include "logger.h"
#define MAX_SIMD_SIZE 32
namespace codings
{
namespace ldpc
{
CCSDSLDPC::CCSDSLDPC(ldpc_rate_t rate, int block_size)
: d_rate(rate), d_block_size(block_size)
{
if (d_rate == RATE_7_8)
{
init_dec(ccsds_78::make_r78_code());
d_frame_size = 8160;
d_codeword_size = 8176;
d_data_size = 7136;
depunc_buffer_in = dsp::create_volk_buffer<int8_t>(d_codeword_size * MAX_SIMD_SIZE);
depunc_buffer_ou = dsp::create_volk_buffer<uint8_t>(d_codeword_size * MAX_SIMD_SIZE);
}
else
{
ccsds_ar4ja::ar4ja_rate_t rate4 = ccsds_ar4ja::AR4JA_RATE_1_2;
if (d_rate == RATE_1_2)
rate4 = ccsds_ar4ja::AR4JA_RATE_1_2;
else if (d_rate == RATE_2_3)
rate4 = ccsds_ar4ja::AR4JA_RATE_2_3;
else if (d_rate == RATE_4_5)
rate4 = ccsds_ar4ja::AR4JA_RATE_4_5;
ccsds_ar4ja::ar4ja_blocksize_t block4 = ccsds_ar4ja::AR4JA_BLOCK_1024;
if (d_block_size == 1024)
block4 = ccsds_ar4ja::AR4JA_BLOCK_1024;
else if (d_block_size == 4096)
block4 = ccsds_ar4ja::AR4JA_BLOCK_4096;
else if (d_block_size == 16384)
block4 = ccsds_ar4ja::AR4JA_BLOCK_16384;
else
throw std::runtime_error("This blocksize is not supported!");
auto pcm = ccsds_ar4ja::make_ar4ja_code(rate4, block4, &d_M);
init_dec(pcm);
d_frame_size = pcm.get_n_cols() - d_M; // Punctured codeword size
d_codeword_size = pcm.get_n_cols(); // Full codeword size
d_data_size = pcm.get_n_rows() - d_M; // Data words size
depunc_buffer_in = dsp::create_volk_buffer<int8_t>(d_codeword_size * MAX_SIMD_SIZE);
depunc_buffer_ou = dsp::create_volk_buffer<uint8_t>(d_codeword_size * MAX_SIMD_SIZE);
}
}
void CCSDSLDPC::init_dec(Sparse_matrix pcm)
{
ldpc_decoder = get_best_ldpc_decoder(pcm);
d_simd = ldpc_decoder->simd();
d_is_geneneric = d_simd == 1;
}
CCSDSLDPC::~CCSDSLDPC()
{
delete ldpc_decoder;
volk_free(depunc_buffer_in);
volk_free(depunc_buffer_ou);
}
int CCSDSLDPC::decode(int8_t *codeword, uint8_t *frame, int iterations)
{
if (d_rate == RATE_7_8)
{
for (int i = 0; i < d_simd; i++)
{
memcpy(&depunc_buffer_in[i * d_codeword_size + 18], &codeword[i * d_frame_size], 8158);
for (int i = 0; i < d_simd; i++) // First 18s are 0s
memset(&depunc_buffer_in[i * d_codeword_size], 0, 18);
}
}
else
{
for (int i = 0; i < d_simd; i++)
{
memcpy(&depunc_buffer_in[i * d_codeword_size], &codeword[i * d_frame_size], d_frame_size);
// Last d_M bits are 0s
memset(&depunc_buffer_in[i * d_codeword_size + d_frame_size], 0, d_M);
}
}
d_corr_errors = 0;
if (d_is_geneneric)
for (int i = 0; i < d_simd; i++)
d_corr_errors += ldpc_decoder->decode(&depunc_buffer_ou[i * d_codeword_size], &depunc_buffer_in[i * d_codeword_size], iterations);
else
d_corr_errors = ldpc_decoder->decode(depunc_buffer_ou, depunc_buffer_in, iterations);
d_corr_errors /= d_simd;
if (d_rate == RATE_7_8)
{
for (int i = 0; i < d_simd; i++)
{
memcpy(&frame[i * d_frame_size], &depunc_buffer_ou[i * d_codeword_size + 18], 8158);
}
}
else
{
for (int i = 0; i < d_simd; i++)
{
memcpy(&frame[i * d_frame_size], &depunc_buffer_ou[i * d_codeword_size], d_frame_size);
}
}
return d_corr_errors;
}
ldpc_rate_t ldpc_rate_from_string(std::string str)
{
if (str == "1/2")
return RATE_1_2;
else if (str == "2/3")
return RATE_2_3;
else if (str == "4/5")
return RATE_4_5;
else if (str == "7/8")
return RATE_7_8;
else
throw std::runtime_error("Invalid LDPC code rate " + str);
}
}
}
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