ft8_lib/ft8/decode.h
2018-12-27 22:33:07 +02:00

21 lines
754 B
C

#pragma once
#include <stdint.h>
struct Candidate {
int16_t score;
int16_t time_offset;
int16_t freq_offset;
uint8_t time_sub;
uint8_t freq_sub;
};
// Localize top N candidates in frequency and time according to their sync strength (looking at Costas symbols)
// We treat and organize the candidate list as a min-heap (empty initially).
int find_sync(const uint8_t *power, int num_blocks, int num_bins, const uint8_t *sync_map, int num_candidates, Candidate *heap);
// Compute log likelihood log(p(1) / p(0)) of 174 message bits
// for later use in soft-decision LDPC decoding
void extract_likelihood(const uint8_t *power, int num_bins, const Candidate & cand, const uint8_t *code_map, float *log174);