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41 lines
581 B
C++
41 lines
581 B
C++
/*
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Encoder for augmented Hadamard codes
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Copyright 2020 Ahmet Inan <inan@aicodix.de>
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*/
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#pragma once
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namespace CODE {
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template <int K>
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class HadamardEncoder
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{
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static const int W = 1 << K;
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static const int N = 1 << (K - 1);
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int8_t mod[W];
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static bool parity(unsigned x)
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{
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x ^= x >> 16;
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x ^= x >> 8;
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x ^= x >> 4;
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x ^= x >> 2;
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x ^= x >> 1;
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return x & 1;
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}
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public:
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HadamardEncoder()
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{
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for (int i = 0; i < W; ++i)
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mod[i] = 1 - 2 * parity(i);
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}
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void operator()(int8_t *code, int msg)
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{
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for (int i = 0; i < N; ++i)
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code[i] = mod[msg&(i|N)];
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}
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};
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}
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