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#include "../common/iir_filter.h"
typedef struct fm_mod {
double samplerate; /* sample rate of in and out */
double offset; /* offset to calculated center frequency */
double amplitude; /* how much amplitude to add to the buff */
double phase; /* current phase of FM (used to shift and modulate ) */
double *sin_tab; /* sine/cosine table for modulation */
} fm_mod_t;
int fm_mod_init(fm_mod_t *mod, double samplerate, double offset, double amplitude);
void fm_mod_exit(fm_mod_t *mod);
void fm_modulate_complex(fm_mod_t *mod, sample_t *frequency, int num, float *baseband);
typedef struct fm_demod {
double samplerate; /* sample rate of in and out */
double phase; /* current rotation phase (used to shift) */
double rot; /* rotation step per sample to shift rx frequency (used to shift) */
double last_phase; /* last phase of FM (used to demodulate) */
iir_filter_t lp[2]; /* filters received IQ signal */
double *sin_tab; /* sine/cosine table rotation */
} fm_demod_t;
int fm_demod_init(fm_demod_t *demod, double samplerate, double offset, double bandwidth);
void fm_demod_exit(fm_demod_t *demod);
void fm_demodulate_complex(fm_demod_t *demod, sample_t *frequency, int length, float *baseband, sample_t *I, sample_t *Q);
void fm_demodulate_real(fm_demod_t *demod, sample_t *frequency, int length, sample_t *baseband, sample_t *I, sample_t *Q);
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