kopia lustrzana https://github.com/OpenRTX/OpenRTX
82 wiersze
3.1 KiB
C++
82 wiersze
3.1 KiB
C++
/***************************************************************************
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* Copyright (C) 2021 by Federico Amedeo Izzo IU2NUO, *
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* Niccolò Izzo IU2KIN *
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* Frederik Saraci IU2NRO *
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* Silvano Seva IU2KWO *
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* *
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* *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 3 of the License, or *
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* (at your option) any later version. *
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* *
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* This program is distributed in the hope that it will be useful, *
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* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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* GNU General Public License for more details. *
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* *
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* You should have received a copy of the GNU General Public License *
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* along with this program; if not, see <http://www.gnu.org/licenses/> *
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***************************************************************************/
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#include <cstdio>
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#include <cstdint>
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#include <random>
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#include "M17/M17Golay.h"
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using namespace std;
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default_random_engine rng;
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/**
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* Generate a mask with a random number of bit errors in random positions.
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*/
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uint32_t generateErrorMask()
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{
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uint32_t errorMask = 0;
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uniform_int_distribution< uint8_t > numErrs(0, 5);
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uniform_int_distribution< uint8_t > errPos(0, 23);
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for(uint8_t i = 0; i < numErrs(rng); i++)
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{
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errorMask |= 1 << errPos(rng);
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}
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return errorMask;
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}
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int main()
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{
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uniform_int_distribution< uint16_t > rndValue(0, 2047);
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for(uint32_t i = 0; i < 10000; i++)
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{
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uint16_t value = rndValue(rng);
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uint32_t cword = golay24_encode(value);
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uint32_t emask = generateErrorMask();
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// Check for correct encoding/decoding in absence of errors
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bool decoding_ok = (golay24_decode(cword) == value);
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// Check for correct encoding/decoding in presence of errors
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uint16_t decoded = golay24_decode(cword ^ emask);
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bool correcting_ok = false;
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// For four or more bit errors, decode should return 0xFFFF (uncorrectable error)
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if((__builtin_popcount(emask) >= 4) && (decoded == 0xFFFF))
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{
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correcting_ok = true;
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}
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// Less than four errors should be corrected.
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if(decoded == value) correcting_ok = true;
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printf("Value %04x, emask %08x errs %d -> d %s, c %s\n", value, emask,
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__builtin_popcount(emask),
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decoding_ok ? "OK" : "FAIL",
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correcting_ok ? "OK" : "FAIL");
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}
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return 0;
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}
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