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Split FSK modem code into separate modulator and demodulator

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This commit is contained in:
Andreas Eversberg
2019-09-01 15:38:16 +02:00
parent 360729d270
commit 6dcc8baad4
9 changed files with 213 additions and 137 deletions
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32
src/libfsk/fsk.h
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@@ -1,14 +1,12 @@
#include "../libfm/fm.h"
typedef struct ffsk {
typedef struct fsk_mod {
void *inst;
int (*send_bit)(void *inst);
void (*receive_bit)(void *inst, int bit, double quality, double level);
fm_demod_t demod;
double bits_per_sample; /* fraction of a bit per sample */
double *sin_tab; /* sine table with correct peak level */
double phaseshift65536[2]; /* how much the phase of fsk synbol changes per sample */
double cycles_per_bit65536[2]; /* cacles of one bit */
double cycles_per_bit65536[2]; /* cycles of one bit */
double tx_phase65536; /* current transmit phase */
double level; /* level (amplitude) of signal */
int coherent; /* set, if coherent TX mode */
@@ -16,15 +14,27 @@ typedef struct ffsk {
double f1_deviation;
int low_bit, high_bit; /* a low or high deviation means which bit? */
int tx_bit; /* current transmitting bit (-1 if not set) */
int rx_bit; /* current receiving bit (-1 if not yet measured) */
double tx_bitpos; /* current transmit position in bit */
} fsk_mod_t;
typedef struct fsk_demod {
void *inst;
void (*receive_bit)(void *inst, int bit, double quality, double level);
fm_demod_t demod;
double bits_per_sample; /* fraction of a bit per sample */
double f0_deviation; /* deviation of frequencies, relative to center */
double f1_deviation;
int low_bit, high_bit; /* a low or high deviation means which bit? */
int rx_bit; /* current receiving bit (-1 if not yet measured) */
double rx_bitpos; /* current receive position in bit (sampleclock) */
double rx_bitadjust; /* how much does a bit change cause the sample clock to be adjusted in phase */
} fsk_t;
} fsk_demod_t;
int fsk_init(fsk_t *fsk, void *inst, int (*send_bit)(void *inst), void (*receive_bit)(void *inst, int bit, double quality, double level), int samplerate, double bitrate, double f0, double f1, double level, int coherent, double bitadjust);
void fsk_cleanup(fsk_t *fsk);
void fsk_receive(fsk_t *fsk, sample_t *sample, int length);
int fsk_send(fsk_t *fsk, sample_t *sample, int length, int add);
void fsk_tx_reset(fsk_t *fsk);
int fsk_mod_init(fsk_mod_t *fsk, void *inst, int (*send_bit)(void *inst), int samplerate, double bitrate, double f0, double f1, double level, int coherent);
void fsk_mod_cleanup(fsk_mod_t *fsk);
int fsk_mod_send(fsk_mod_t *fsk, sample_t *sample, int length, int add);
void fsk_mod_tx_reset(fsk_mod_t *fsk);
int fsk_demod_init(fsk_demod_t *fsk, void *inst, void (*receive_bit)(void *inst, int bit, double quality, double level), int samplerate, double bitrate, double f0, double f1, double bitadjust);
void fsk_demod_cleanup(fsk_demod_t *fsk);
void fsk_demod_receive(fsk_demod_t *fsk, sample_t *sample, int length);