SDR: Move FM modulation algorithms to a seperate file

1 files changed, 24 insertions, 0 deletions

diff --git a/src/common/fm_modulation.h b/src/common/fm_modulation.h
new file mode 100644
index 0000000..194ae3f
--- /dev/null
+++ b/src/common/fm_modulation.h
@@ -0,0 +1,24 @@
+
+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;
+
+void fm_mod_init(fm_mod_t *mod, double samplerate, double offset, double amplitude);
+void fm_modulate(fm_mod_t *mod, sample_t *samples, int num, float *buff);
+
+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) */
+	filter_t lp[2];		/* filters received IQ signal */
+	double *sin_tab;	/* sine/cosine table rotation */
+} fm_demod_t;
+
+void fm_demod_init(fm_demod_t *demod, double samplerate, double offset, double bandwidth);
+void fm_demodulate(fm_demod_t *demod, sample_t *samples, int num, float *buff);
+