mayhem-firmware/firmware/common/bch_code.hpp
furrtek 24abe4b427 Yet another POCSAG bugfix (multi-batch messages are not cut anymore)
Added BCH ECC functions for checking, error correction and encoding
2017-02-06 20:32:33 +00:00

62 lines
1.9 KiB
C++

/*
* Copyright (C) 2015 Craig Shelley (craig@microtron.org.uk)
* Copyright (C) 2016 Furrtek
*
* BCH Encoder/Decoder - Adapted from GNURadio
*
* This file is part of PortaPack.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifndef __BCHCODE_H__
#define __BCHCODE_H__
#include <vector>
class BCHCode {
public:
BCHCode(std::vector<int> p_init, int m, int n, int k, int t);
~BCHCode();
BCHCode(const BCHCode&) = delete;
BCHCode(BCHCode&&) = delete;
BCHCode& operator=(const BCHCode&) = delete;
BCHCode& operator=(BCHCode&&) = delete;
int * encode(int data[]);
int decode(int recd[]);
private:
void gen_poly();
void generate_gf();
bool valid { false };
int d { };
int * p { }; // coefficients of primitive polynomial used to generate GF(2**5)
int m { }; // order of the field GF(2**5) = 5
int n { }; // 2**5 - 1 = 31
int k { }; // n - deg(g(x)) = 21 = dimension
int t { }; // 2 = error correcting capability
int * alpha_to { }; // log table of GF(2**5)
int * index_of { }; // antilog table of GF(2**5)
int * g { }; // coefficients of generator polynomial, g(x) [n - k + 1]=[11]
int * bb { }; // coefficients of redundancy polynomial ( x**(10) i(x) ) modulo g(x)
};
#endif/*__BCHCODE_H__*/