M17_Implementations/SP5WWP/include/m17/m17.h

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5.6 KiB
C

//--------------------------------------------------------------------
// M17 C library - m17.h
//
// Wojciech Kaczmarski, SP5WWP
// M17 Project, 29 December 2023
//--------------------------------------------------------------------
#pragma once
#ifdef __cplusplus
extern "C" {
#endif
#include <stdint.h>
#include <stddef.h>
// M17 C library - lib/lib.c
#define BSB_SPS 10 //samples per symbol
#define FLT_SPAN 8 //baseband RRC filter span in symbols
#define SYM_PER_SWD 8 //symbols per syncword
#define SW_LEN (BSB_SPS*SYM_PER_SWD) //syncword detector length
#define SYM_PER_PLD 184 //symbols per payload in a frame
#define SYM_PER_FRA 192 //symbols per whole 40 ms frame
#define RRC_DEV 7168.0f //.rrc file deviation for +1.0 symbol
//L2 metric threshold
#define DIST_THRESH 2.0f //threshold for distance (syncword detection)
void send_preamble(float out[SYM_PER_FRA], uint32_t *cnt, const uint8_t type);
void send_syncword(float out[SYM_PER_SWD], uint32_t *cnt, const uint16_t syncword);
void send_data(float out[SYM_PER_PLD], uint32_t *cnt, const uint8_t* in);
void send_eot(float out[SYM_PER_FRA], uint32_t *cnt);
// M17 C library - lib/payload/call.c
#define CHAR_MAP " ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-/."
void decode_callsign_bytes(uint8_t *outp, const uint8_t inp[6]);
void decode_callsign_value(uint8_t *outp, const uint64_t inp);
int8_t encode_callsign_bytes(uint8_t out[6], const uint8_t *inp);
int8_t encode_callsign_value(uint64_t *out, const uint8_t *inp);
// M17 C library - payload
/**
* @brief Structure holding Link Setup Frame data.
*
*/
struct LSF
{
uint8_t dst[6];
uint8_t src[6];
uint8_t type[2];
uint8_t meta[112/8];
uint8_t crc[2];
};
// M17 C library - lib/encode/convol.c
extern const uint8_t puncture_pattern_1[61];
extern const uint8_t puncture_pattern_2[12];
extern const uint8_t puncture_pattern_3[8];
void conv_encode_stream_frame(uint8_t* out, const uint8_t* in, const uint16_t fn);
void conv_encode_packet_frame(uint8_t* out, const uint8_t* in);
void conv_encode_LSF(uint8_t* out, const struct LSF *in);
// M17 C library - lib/payload/crc.c
//M17 CRC polynomial
extern const uint16_t M17_CRC_POLY;
uint16_t CRC_M17(const uint8_t *in, const uint16_t len);
uint16_t LSF_CRC(const struct LSF *in);
// M17 C library - lib/payload/lich.c
void extract_LICH(uint8_t outp[6], const uint8_t cnt, const struct LSF *inp);
void unpack_LICH(uint8_t *out, const uint8_t in[12]);
// M17 C library - lib/math/golay.c
extern const uint16_t encode_matrix[12];
extern const uint16_t decode_matrix[12];
uint32_t golay24_encode(const uint16_t data);
uint16_t golay24_sdecode(const uint16_t codeword[24]);
void decode_LICH(uint8_t outp[6], const uint16_t inp[96]);
void encode_LICH(uint8_t outp[12], const uint8_t inp[6]);
// M17 C library - lib/phy/interleave.c
//interleaver pattern
extern const uint16_t intrl_seq[SYM_PER_PLD*2];
void reorder_bits(uint8_t outp[SYM_PER_PLD*2], const uint8_t inp[SYM_PER_PLD*2]);
void reorder_soft_bits(uint16_t outp[SYM_PER_PLD*2], const uint16_t inp[SYM_PER_PLD*2]);
// M17 C library - lib/math/math.c
uint16_t q_abs_diff(const uint16_t v1, const uint16_t v2);
float eucl_norm(const float* in1, const int8_t* in2, const uint8_t n);
void int_to_soft(uint16_t* out, const uint16_t in, const uint8_t len);
uint16_t soft_to_int(const uint16_t* in, const uint8_t len);
uint16_t div16(const uint16_t a, const uint16_t b);
uint16_t mul16(const uint16_t a, const uint16_t b);
uint16_t soft_bit_XOR(const uint16_t a, const uint16_t b);
uint16_t soft_bit_NOT(const uint16_t a);
void soft_XOR(uint16_t* out, const uint16_t* a, const uint16_t* b, const uint8_t len);
// M17 C library - lib/phy/randomize.c
//randomizing pattern
extern const uint8_t rand_seq[46];
void randomize_bits(uint8_t inp[SYM_PER_PLD*2]);
void randomize_soft_bits(uint16_t inp[SYM_PER_PLD*2]);
// M17 C library - lib/phy/slice.c
void slice_symbols(uint16_t out[2*SYM_PER_PLD], const float inp[SYM_PER_PLD]);
// M17 C library - lib/math/rrc.c
//sample RRC filter for 48kHz sample rate
//alpha=0.5, span=8, sps=10, gain=sqrt(sps)
extern const float rrc_taps_10[8*10+1];
//sample RRC filter for 24kHz sample rate
//alpha=0.5, span=8, sps=5, gain=sqrt(sps)
extern const float rrc_taps_5[8*5+1];
// M17 C library - lib/encode/symbols.c
// dibits-symbols map (TX)
extern const int8_t symbol_map[4];
extern const int8_t symbol_list[4];
// M17 C library - lib/phy/sync.c
//syncwords
extern const uint16_t SYNC_LSF;
extern const uint16_t SYNC_STR;
extern const uint16_t SYNC_PKT;
extern const uint16_t SYNC_BER;
extern const uint16_t EOT_MRKR;
// M17 C library - lib/decode/viterbi.c
#define K 5 //constraint length
#define NUM_STATES (1 << (K - 1)) //number of states
uint32_t viterbi_decode(uint8_t* out, const uint16_t* in, const uint16_t len);
uint32_t viterbi_decode_punctured(uint8_t* out, const uint16_t* in, const uint8_t* punct, const uint16_t in_len, const uint16_t p_len);
void viterbi_decode_bit(uint16_t s0, uint16_t s1, size_t pos);
uint32_t viterbi_chainback(uint8_t* out, size_t pos, const uint16_t len);
void viterbi_reset(void);
//End of Transmission symbol pattern
extern const float eot_symbols[8];
// M17 C library - decode/symbols.c
// syncword patterns (RX)
// TODO: Compute those at runtime from the consts below
extern const int8_t lsf_sync_symbols[8];
extern const int8_t str_sync_symbols[8];
extern const int8_t pkt_sync_symbols[8];
// symbol levels (RX)
extern const float symbol_levels[4];
#ifdef __cplusplus
}
#endif