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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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17
src/nmt/dsp.c
View File

@@ -120,7 +120,11 @@ int dsp_init_sender(nmt_t *nmt, double deviation_factor)
PDEBUG(DDSP, DEBUG_DEBUG, "Using Supervisory level of %.3f (%.3f KHz deviation @ 4015 Hz)\n", TX_PEAK_SUPER * deviation_factor, 0.3 * deviation_factor);
/* init fsk */
if (fsk_init(&nmt->fsk, nmt, fsk_send_bit, fsk_receive_bit, nmt->sender.samplerate, BIT_RATE, F0, F1, TX_PEAK_FSK, 1, BIT_ADJUST) < 0) {
if (fsk_mod_init(&nmt->fsk_mod, nmt, fsk_send_bit, nmt->sender.samplerate, BIT_RATE, F0, F1, TX_PEAK_FSK, 1) < 0) {
PDEBUG_CHAN(DDSP, DEBUG_ERROR, "FSK init failed!\n");
return -EINVAL;
}
if (fsk_demod_init(&nmt->fsk_demod, nmt, fsk_receive_bit, nmt->sender.samplerate, BIT_RATE, F0, F1, BIT_ADJUST) < 0) {
PDEBUG_CHAN(DDSP, DEBUG_ERROR, "FSK init failed!\n");
return -EINVAL;
}
@@ -163,7 +167,8 @@ void dsp_cleanup_sender(nmt_t *nmt)
{
PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Cleanup DSP for Transceiver.\n");
fsk_cleanup(&nmt->fsk);
fsk_mod_cleanup(&nmt->fsk_mod);
fsk_demod_cleanup(&nmt->fsk_demod);
if (nmt->super_filter_spl) {
free(nmt->super_filter_spl);
@@ -336,7 +341,7 @@ void sender_receive(sender_t *sender, sample_t *samples, int length, double __at
nmt->super_filter_pos = pos;
/* fsk signal */
fsk_receive(&nmt->fsk, samples, length);
fsk_demod_receive(&nmt->fsk_demod, samples, length);
/* muting audio while receiving frame */
for (i = 0; i < length; i++) {
@@ -449,7 +454,7 @@ again:
jitter_load(&nmt->sender.dejitter, samples, length);
/* send after dejitter, so audio is flushed */
if (nmt->dms.tx_frame_valid) {
fsk_send(&nmt->fsk, samples, length, 0);
fsk_mod_send(&nmt->fsk_mod, samples, length, 0);
break;
}
if (nmt->supervisory)
@@ -464,7 +469,7 @@ again:
case DSP_MODE_FRAME:
/* Encode frame into audio stream. If frames have
* stopped, process again for rest of stream. */
count = fsk_send(&nmt->fsk, samples, length, 0);
count = fsk_mod_send(&nmt->fsk_mod, samples, length, 0);
/* special case: add supervisory signal to frame at loop test */
if (nmt->sender.loopback && nmt->supervisory)
super_encode(nmt, samples, count);
@@ -501,7 +506,7 @@ void nmt_set_dsp_mode(nmt_t *nmt, enum dsp_mode mode)
{
/* reset frame */
if (mode == DSP_MODE_FRAME && nmt->dsp_mode != mode) {
fsk_tx_reset(&nmt->fsk);
fsk_mod_tx_reset(&nmt->fsk_mod);
nmt->tx_frame_length = 0;
}

3
src/nmt/nmt.h
View File

@@ -104,7 +104,8 @@ typedef struct nmt {
/* dsp states */
enum dsp_mode dsp_mode; /* current mode: audio, durable tone 0 or 1, paging */
fsk_t fsk; /* fsk processing */
fsk_mod_t fsk_mod; /* fsk processing */
fsk_demod_t fsk_demod;
int super_samples; /* number of samples in buffer for supervisory detection */
goertzel_t super_goertzel[5]; /* filter for supervisory decoding */
sample_t *super_filter_spl; /* array with sample buffer for supervisory detection */