WSJT-X/lib/qra/q65/qracodes.h

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2020-10-25 20:10:53 -04:00
// qracodes.h
// Q-ary RA codes encoding/decoding functions
//
// (c) 2016 - Nico Palermo, IV3NWV - Microtelecom Srl, Italy
// ------------------------------------------------------------------------------
// This file is part of the qracodes project, a Forward Error Control
// encoding/decoding package based on Q-ary RA (Repeat and Accumulate) LDPC codes.
//
// qracodes 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 3 of the License, or
// (at your option) any later version.
// qracodes 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 qracodes source distribution.
// If not, see <http://www.gnu.org/licenses/>.
#ifndef _qracodes_h_
#define _qracodes_h_
// type of codes
#define QRATYPE_NORMAL 0x00 // normal code
#define QRATYPE_CRC 0x01 // code with crc - last information symbol is a CRC-6
#define QRATYPE_CRCPUNCTURED 0x02 // the CRC-6 symbol is punctured (not sent along the channel)
#define QRATYPE_CRCPUNCTURED2 0x03 // code with CRC-12. The two crc symbols are punctured
typedef struct {
// code parameters
const int K; // number of information symbols
const int N; // codeword length in symbols
const int m; // bits/symbol
const int M; // Symbol alphabet cardinality (2^m)
const int a; // code grouping factor
const int NC; // number of check symbols (N-K)
const int V; // number of variables in the code graph (N)
const int C; // number of factors in the code graph (N +(N-K)+1)
const int NMSG; // number of msgs in the code graph
const int MAXVDEG; // maximum variable degree
const int MAXCDEG; // maximum factor degree
const int type; // see QRATYPE_xx defines
const float R; // code rate (K/N)
const char name[64]; // code name
// tables used by the encoder
const int *acc_input_idx;
const int *acc_input_wlog;
const int *gflog;
const int *gfexp;
// tables used by the decoder -------------------------
const int *msgw;
const int *vdeg;
const int *cdeg;
const int *v2cmidx;
const int *c2vmidx;
const int *gfpmat;
} qracode;
// Uncomment the header file of the code which needs to be tested
//#include "qra12_63_64_irr_b.h" // irregular code (12,63) over GF(64)
//#include "qra13_64_64_irr_e.h" // irregular code with good performance and best UER protection at AP56
//#include "qra13_64_64_reg_a.h" // regular code with good UER but perf. inferior to that of code qra12_63_64_irr_b
#ifdef __cplusplus
extern "C" {
#endif
int qra_encode(const qracode *pcode, int *y, const int *x);
float qra_mfskbesselmetric(float *pix, const float *rsq, const int m, const int N, float EsNoMetric);
int qra_extrinsic(const qracode *pcode, float *pex, const float *pix, int maxiter,float *qra_v2cmsg,float *qra_c2vmsg);
void qra_mapdecode(const qracode *pcode, int *xdec, float *pex, const float *pix);
#ifdef __cplusplus
}
#endif
#endif // _qracodes_h_