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