#pragma once #include namespace ft8 { constexpr float FSK_dev = 6.25f; // tone deviation in Hz and symbol rate // Define FT8 symbol counts constexpr int ND = 58; // Data symbols constexpr int NS = 21; // Sync symbols (3 @ Costas 7x7) constexpr int NN = NS + ND; // Total channel symbols (79) // Define the LDPC sizes constexpr int N = 174; // Number of bits in the encoded message constexpr int K = 91; // Number of payload bits constexpr int M = N - K; // Number of checksum bits constexpr int K_BYTES = (K + 7) / 8; // Number of whole bytes needed to store K bits // Define CRC parameters constexpr uint16_t CRC_POLYNOMIAL = 0x2757; // CRC-14 polynomial without the leading (MSB) 1 constexpr int CRC_WIDTH = 14; // Costas 7x7 tone pattern extern const uint8_t kCostas_map[7]; // Gray code map extern const uint8_t kGray_map[8]; // Parity generator matrix for (174,91) LDPC code, stored in bitpacked format (MSB first) extern const uint8_t kGenerator[M][K_BYTES]; // Column order (permutation) in which the bits in codeword are stored // (Not really used in FT8 v2 - instead the Nm, Mn and generator matrices are already permuted) extern const uint8_t kColumn_order[N]; // this is the LDPC(174,91) parity check matrix. // 83 rows. // each row describes one parity check. // each number is an index into the codeword (1-origin). // the codeword bits mentioned in each row must xor to zero. // From WSJT-X's ldpc_174_91_c_reordered_parity.f90. extern const uint8_t kNm[M][7]; // Mn from WSJT-X's bpdecode174.f90. // each row corresponds to a codeword bit. // the numbers indicate which three parity // checks (rows in Nm) refer to the codeword bit. // 1-origin. extern const uint8_t kMn[N][3]; // Number of rows (columns in C/C++) in the array Nm. extern const uint8_t kNrw[M]; }