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70 lines
1.1 KiB
C
70 lines
1.1 KiB
C
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/*
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LDPC SISO encoder
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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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LDPCInterface *ldpc;
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int N, K, R;
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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 ldpc;
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initialized = true;
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ldpc = it->clone();
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N = ldpc->code_len();
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K = ldpc->data_len();
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R = N - K;
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}
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void operator()(TYPE *data, TYPE *parity)
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{
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for (int i = 0; i < R; ++i)
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parity[i] = one();
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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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parity[i] = sign(parity[i], data[j]);
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}
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ldpc->next_bit();
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}
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for (int i = 1; i < R; ++i)
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parity[i] = sign(parity[i], parity[i-1]);
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}
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~LDPCEncoder()
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{
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if (initialized)
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delete ldpc;
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}
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};
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} // namespace ldpctool
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#endif
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