Correcting all levels and move all remaining integer samples to sample_t

The leves are based on the standards of each mobile network. They
are adjusted to the specified frequency deviation now.
This commit is contained in:
Andreas Eversberg 2017-01-29 07:25:12 +01:00
parent bd7ccc5fa0
commit 7e45f556ce
38 changed files with 484 additions and 397 deletions

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@ -54,7 +54,7 @@ A caller must not know the location of the phone anymore to reach the right base
<li>Channel spacing: 10 KHz and optionally 12.5 KHz <li>Channel spacing: 10 KHz and optionally 12.5 KHz
<li>Voice modulation: FM <li>Voice modulation: FM
<li>Signaling modulation: carrier FSK <li>Signaling modulation: carrier FSK
<li>Frequency deviation: 2.5 KHz (FSK); 2.4 KHz (Voice) <li>Frequency deviation: 2.5 KHz (FSK); 4 KHz (Voice)
<li>Mobile station transmit power: 50 mW up to 15 Watts <li>Mobile station transmit power: 50 mW up to 15 Watts
<li>Base station transmit power: 25 Watts <li>Base station transmit power: 25 Watts
<li>Features: Speech Compandor, Audio scrambling <li>Features: Speech Compandor, Audio scrambling

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@ -135,14 +135,14 @@ typedef struct amps {
goertzel_t sat_goertzel[5]; /* filter for SAT signal decoding */ goertzel_t sat_goertzel[5]; /* filter for SAT signal decoding */
sample_t *sat_filter_spl; /* array with sample buffer for supervisory detection */ sample_t *sat_filter_spl; /* array with sample buffer for supervisory detection */
int sat_filter_pos; /* current sample position in filter_spl */ int sat_filter_pos; /* current sample position in filter_spl */
double sat_phaseshift256[3]; /* how much the phase of sine wave changes per sample */ double sat_phaseshift65536[3]; /* how much the phase of sine wave changes per sample */
double sat_phase256; /* current phase */ double sat_phase65536; /* current phase */
int sat_detected; /* current detection state flag */ int sat_detected; /* current detection state flag */
int sat_detect_count; /* current number of consecutive detections/losses */ int sat_detect_count; /* current number of consecutive detections/losses */
int sig_detected; /* current detection state flag */ int sig_detected; /* current detection state flag */
int sig_detect_count; /* current number of consecutive detections/losses */ int sig_detect_count; /* current number of consecutive detections/losses */
double test_phaseshift256; /* how much the phase of sine wave changes per sample */ double test_phaseshift65536; /* how much the phase of sine wave changes per sample */
double test_phase256; /* current phase */ double test_phase65536; /* current phase */
transaction_t *trans_list; /* list of transactions */ transaction_t *trans_list; /* list of transactions */

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@ -99,10 +99,13 @@
#define PI M_PI #define PI M_PI
#define BANDWIDTH 20000.0 /* maximum bandwidth */ #define MAX_DEVIATION 8000.0
#define FSK_DEVIATION 32767.0 /* +-8 KHz */ #define MAX_MODULATION 10000.0
#define SAT_DEVIATION 8192.0 /* +-2 KHz */ #define DBM0_DEVIATION 2900.0 /* deviation of dBm0 at 1 kHz */
#define COMPANDOR_0DB 45000 /* works quite well */ #define COMPANDOR_0DB 1.0 /* A level of 0dBm (1.0) shall be unaccected */
#define FSK_DEVIATION (8000.0 / DBM0_DEVIATION) /* no emphasis */
#define SAT_DEVIATION (2000.0 / DBM0_DEVIATION) /* no emphasis */
#define MAX_DISPLAY (8000.0 / DBM0_DEVIATION) /* no emphasis */
#define BITRATE 10000 #define BITRATE 10000
#define SIG_TONE_CROSSINGS 2000 /* 2000 crossings are 100ms @ 10 KHz */ #define SIG_TONE_CROSSINGS 2000 /* 2000 crossings are 100ms @ 10 KHz */
#define SIG_TONE_MINBITS 950 /* minimum bit durations to detect signaling tone (1000 is perfect for 100 ms) */ #define SIG_TONE_MINBITS 950 /* minimum bit durations to detect signaling tone (1000 is perfect for 100 ms) */
@ -116,7 +119,7 @@
#define CUT_OFF_HIGHPASS 300.0 /* cut off frequency for high pass filter to remove dc level from sound card / sample */ #define CUT_OFF_HIGHPASS 300.0 /* cut off frequency for high pass filter to remove dc level from sound card / sample */
#define BEST_QUALITY 0.68 /* Best possible RX quality */ #define BEST_QUALITY 0.68 /* Best possible RX quality */
static int16_t ramp_up[256], ramp_down[256]; static sample_t ramp_up[256], ramp_down[256];
static double sat_freq[5] = { static double sat_freq[5] = {
5970.0, 5970.0,
@ -126,8 +129,8 @@ static double sat_freq[5] = {
10000.0, /* signaling tone */ 10000.0, /* signaling tone */
}; };
static int dsp_sine_sat[256]; static sample_t dsp_sine_sat[65536];
static int dsp_sine_test[256]; static sample_t dsp_sine_test[65536];
static uint8_t dsp_sync_check[0x800]; static uint8_t dsp_sync_check[0x800];
@ -138,10 +141,10 @@ void dsp_init(void)
double s; double s;
PDEBUG(DDSP, DEBUG_DEBUG, "Generating sine table for SAT signal.\n"); PDEBUG(DDSP, DEBUG_DEBUG, "Generating sine table for SAT signal.\n");
for (i = 0; i < 256; i++) { for (i = 0; i < 65536; i++) {
s = sin((double)i / 256.0 * 2.0 * PI); s = sin((double)i / 65536.0 * 2.0 * PI);
dsp_sine_sat[i] = (int)(s * SAT_DEVIATION); dsp_sine_sat[i] = s * SAT_DEVIATION;
dsp_sine_test[i] = (int)(s * FSK_DEVIATION); dsp_sine_test[i] = s * FSK_DEVIATION;
} }
/* sync checker */ /* sync checker */
@ -170,7 +173,7 @@ static void dsp_init_ramp(amps_t *amps)
else else
c = sqrt(c); c = sqrt(c);
#endif #endif
ramp_down[i] = (int)(c * (double)amps->fsk_deviation); ramp_down[i] = c * (double)amps->fsk_deviation;
ramp_up[i] = -ramp_down[i]; ramp_up[i] = -ramp_down[i];
} }
} }
@ -190,9 +193,8 @@ int dsp_init_sender(amps_t *amps, int tolerant)
PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Init DSP for transceiver.\n"); PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Init DSP for transceiver.\n");
/* set deviation and modulation parameters */ /* set modulation parameters */
amps->sender.bandwidth = BANDWIDTH; sender_set_fm(&amps->sender, MAX_DEVIATION, MAX_MODULATION, DBM0_DEVIATION, MAX_DISPLAY);
amps->sender.sample_deviation = 8000.0 / (double)FSK_DEVIATION;
if (amps->sender.samplerate < 96000) { if (amps->sender.samplerate < 96000) {
PDEBUG(DDSP, DEBUG_ERROR, "Sample rate must be at least 96000 Hz to process FSK and SAT signals.\n"); PDEBUG(DDSP, DEBUG_ERROR, "Sample rate must be at least 96000 Hz to process FSK and SAT signals.\n");
@ -229,7 +231,7 @@ int dsp_init_sender(amps_t *amps, int tolerant)
amps->fsk_rx_window = spl; amps->fsk_rx_window = spl;
/* create devation and ramp */ /* create devation and ramp */
amps->fsk_deviation = FSK_DEVIATION; /* be sure not to overflow 32767 */ amps->fsk_deviation = FSK_DEVIATION;
dsp_init_ramp(amps); dsp_init_ramp(amps);
/* allocate ring buffer for SAT signal detection */ /* allocate ring buffer for SAT signal detection */
@ -245,15 +247,15 @@ int dsp_init_sender(amps_t *amps, int tolerant)
for (i = 0; i < 5; i++) { for (i = 0; i < 5; i++) {
audio_goertzel_init(&amps->sat_goertzel[i], sat_freq[i], amps->sender.samplerate); audio_goertzel_init(&amps->sat_goertzel[i], sat_freq[i], amps->sender.samplerate);
if (i < 3) { if (i < 3) {
amps->sat_phaseshift256[i] = 256.0 / ((double)amps->sender.samplerate / sat_freq[i]); amps->sat_phaseshift65536[i] = 65536.0 / ((double)amps->sender.samplerate / sat_freq[i]);
PDEBUG(DDSP, DEBUG_DEBUG, "sat_phaseshift256[%d] = %.4f\n", i, amps->sat_phaseshift256[i]); PDEBUG(DDSP, DEBUG_DEBUG, "sat_phaseshift65536[%d] = %.4f\n", i, amps->sat_phaseshift65536[i]);
} }
} }
sat_reset(amps, "Initial state"); sat_reset(amps, "Initial state");
/* test tone */ /* test tone */
amps->test_phaseshift256 = 256.0 / ((double)amps->sender.samplerate / 1000.0); amps->test_phaseshift65536 = 65536.0 / ((double)amps->sender.samplerate / 1000.0);
PDEBUG(DDSP, DEBUG_DEBUG, "test_phaseshift256 = %.4f\n", amps->test_phaseshift256); PDEBUG(DDSP, DEBUG_DEBUG, "test_phaseshift65536 = %.4f\n", amps->test_phaseshift65536);
/* be more tolerant when syncing */ /* be more tolerant when syncing */
amps->fsk_rx_sync_tolerant = tolerant; amps->fsk_rx_sync_tolerant = tolerant;
@ -401,7 +403,7 @@ again:
//printf("pos=%d length=%d copy=%d\n", pos, length, copy); //printf("pos=%d length=%d copy=%d\n", pos, length, copy);
for (i = 0; i < copy; i++) { for (i = 0; i < copy; i++) {
#ifdef DEBUG_ENCODER #ifdef DEBUG_ENCODER
puts(debug_amplitude((double)spl[pos] / 32767.0)); puts(debug_amplitude((double)spl[pos]));
#endif #endif
*samples++ = spl[pos++]; *samples++ = spl[pos++];
} }
@ -422,26 +424,19 @@ done:
static void sat_encode(amps_t *amps, sample_t *samples, int length) static void sat_encode(amps_t *amps, sample_t *samples, int length)
{ {
double phaseshift, phase; double phaseshift, phase;
int32_t sample;
int i; int i;
phaseshift = amps->sat_phaseshift256[amps->sat]; phaseshift = amps->sat_phaseshift65536[amps->sat];
phase = amps->sat_phase256; phase = amps->sat_phase65536;
for (i = 0; i < length; i++) { for (i = 0; i < length; i++) {
sample = *samples; *samples++ += dsp_sine_sat[(uint16_t)phase];
sample += dsp_sine_sat[(uint8_t)phase];
if (sample > 32767)
sample = 32767;
else if (sample < -32767)
sample = -32767;
*samples++ = sample;
phase += phaseshift; phase += phaseshift;
if (phase >= 256) if (phase >= 65536)
phase -= 256; phase -= 65536;
} }
amps->sat_phase256 = phase; amps->sat_phase65536 = phase;
} }
static void test_tone_encode(amps_t *amps, sample_t *samples, int length) static void test_tone_encode(amps_t *amps, sample_t *samples, int length)
@ -449,17 +444,17 @@ static void test_tone_encode(amps_t *amps, sample_t *samples, int length)
double phaseshift, phase; double phaseshift, phase;
int i; int i;
phaseshift = amps->test_phaseshift256; phaseshift = amps->test_phaseshift65536;
phase = amps->test_phase256; phase = amps->test_phase65536;
for (i = 0; i < length; i++) { for (i = 0; i < length; i++) {
*samples++ = dsp_sine_test[(uint8_t)phase]; *samples++ = dsp_sine_test[(uint16_t)phase];
phase += phaseshift; phase += phaseshift;
if (phase >= 256) if (phase >= 65536)
phase -= 256; phase -= 65536;
} }
amps->test_phase256 = phase; amps->test_phase65536 = phase;
} }
/* Provide stream of audio toward radio unit */ /* Provide stream of audio toward radio unit */
@ -735,9 +730,9 @@ static void sat_decode(amps_t *amps, sample_t *samples, int length)
if (quality[1] < 0) if (quality[1] < 0)
quality[1] = 0; quality[1] = 0;
PDEBUG_CHAN(DDSP, DEBUG_NOTICE, "SAT level %.2f%% quality %.0f%%\n", result[0] * 32767.0 / SAT_DEVIATION / 0.63662 * 100.0, quality[0] * 100.0); PDEBUG_CHAN(DDSP, DEBUG_NOTICE, "SAT level %.2f%% quality %.0f%%\n", result[0] / SAT_DEVIATION / 0.63662 * 100.0, quality[0] * 100.0);
if (amps->sender.loopback || debuglevel == DEBUG_DEBUG) { if (amps->sender.loopback || debuglevel == DEBUG_DEBUG) {
PDEBUG_CHAN(DDSP, debuglevel, "Signaling Tone level %.2f%% quality %.0f%%\n", result[2] * 32767.0 / FSK_DEVIATION / 0.63662 * 100.0, quality[1] * 100.0); PDEBUG_CHAN(DDSP, debuglevel, "Signaling Tone level %.2f%% quality %.0f%%\n", result[2] / FSK_DEVIATION / 0.63662 * 100.0, quality[1] * 100.0);
} }
if (quality[0] > SAT_QUALITY) { if (quality[0] > SAT_QUALITY) {
if (amps->sat_detected == 0) { if (amps->sat_detected == 0) {

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@ -33,12 +33,12 @@ typedef struct anetz {
int fsk_filter_pos; /* current sample position in filter_spl */ int fsk_filter_pos; /* current sample position in filter_spl */
int tone_detected; /* what tone has been detected */ int tone_detected; /* what tone has been detected */
int tone_count; /* how long has that tone been detected */ int tone_count; /* how long has that tone been detected */
double tone_phaseshift256; /* how much the phase of sine wave changes per sample */ double tone_phaseshift65536; /* how much the phase of sine wave changes per sample */
double tone_phase256; /* current phase */ double tone_phase65536; /* current phase */
double page_gain; /* factor to raise the paging tones */ double page_gain; /* factor to raise the paging tones */
int page_sequence; /* if set, use paging tones in sequence rather than parallel */ int page_sequence; /* if set, use paging tones in sequence rather than parallel */
double paging_phaseshift256[4];/* how much the phase of sine wave changes per sample */ double paging_phaseshift65536[4];/* how much the phase of sine wave changes per sample */
double paging_phase256[4]; /* current phase */ double paging_phase65536[4]; /* current phase */
int paging_tone; /* current tone (0..3) in sequenced mode */ int paging_tone; /* current tone (0..3) in sequenced mode */
int paging_count; /* current sample count of tone in seq. mode */ int paging_count; /* current sample count of tone in seq. mode */
int paging_transition; /* set to number of samples during transition */ int paging_transition; /* set to number of samples during transition */

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@ -35,8 +35,12 @@
#define PI 3.1415927 #define PI 3.1415927
/* signaling */ /* signaling */
#define BANDWIDTH 15000.0 /* maximum bandwidth */ #define MAX_DEVIATION 15000.0
#define TX_PEAK_TONE 8192.0 /* peak amplitude for all tones */ #define MAX_MODULATION 4000.0
#define DBM0_DEVIATION 10500.0 /* deviation of dBm0 at 1 kHz */
#define TX_PEAK_TONE (10500.0 / DBM0_DEVIATION) /* 10.5 kHz, no emphasis */
#define TX_PEAK_PAGE (15000.0 / DBM0_DEVIATION) /* 15 kHz, no emphasis */
#define MAX_DISPLAY (15000.0 / DBM0_DEVIATION) /* 15 kHz, no emphasis */
#define CHUNK_DURATION 0.010 /* 10 ms */ #define CHUNK_DURATION 0.010 /* 10 ms */
// FIXME: how long until we detect a tone? // FIXME: how long until we detect a tone?
@ -53,7 +57,8 @@ static double fsk_tones[2] = {
}; };
/* table for fast sine generation */ /* table for fast sine generation */
sample_t dsp_sine_tone[256]; static sample_t dsp_sine_tone[65536];
static sample_t dsp_sine_page[65536];
/* global init for audio processing */ /* global init for audio processing */
void dsp_init(void) void dsp_init(void)
@ -62,14 +67,10 @@ void dsp_init(void)
double s; double s;
PDEBUG(DDSP, DEBUG_DEBUG, "Generating sine tables.\n"); PDEBUG(DDSP, DEBUG_DEBUG, "Generating sine tables.\n");
for (i = 0; i < 256; i++) { for (i = 0; i < 65536; i++) {
s = sin((double)i / 256.0 * 2.0 * PI); s = sin((double)i / 65536.0 * 2.0 * PI);
dsp_sine_tone[i] = (int)(s * TX_PEAK_TONE); dsp_sine_tone[i] = s * TX_PEAK_TONE;
} dsp_sine_page[i] = s * TX_PEAK_PAGE;
if (TX_PEAK_TONE > 32767.0) {
fprintf(stderr, "TX_PEAK_TONE definition too high, please fix!\n");
abort();
} }
} }
@ -82,15 +83,10 @@ int dsp_init_sender(anetz_t *anetz, double page_gain, int page_sequence)
PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Init DSP for 'Sender'.\n"); PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Init DSP for 'Sender'.\n");
/* set deviation and modulation parameters */ /* set modulation parameters */
anetz->sender.bandwidth = BANDWIDTH; sender_set_fm(&anetz->sender, MAX_DEVIATION * page_gain, MAX_MODULATION, DBM0_DEVIATION, MAX_DISPLAY);
anetz->sender.sample_deviation = 11000.0 / (double)TX_PEAK_TONE;
anetz->page_gain = page_gain; anetz->page_gain = page_gain;
if (page_gain * TX_PEAK_TONE > 32767.0) {
page_gain = 32767.0 / TX_PEAK_TONE;
PDEBUG_CHAN(DDSP, DEBUG_NOTICE, "Highest possible gain of paging tones is %.1f dB.\n", log10(page_gain) * 20);
}
anetz->page_sequence = page_sequence; anetz->page_sequence = page_sequence;
audio_init_loss(&anetz->sender.loss, LOSS_INTERVAL, anetz->sender.loss_volume, LOSS_TIME); audio_init_loss(&anetz->sender.loss, LOSS_INTERVAL, anetz->sender.loss_volume, LOSS_TIME);
@ -109,8 +105,8 @@ int dsp_init_sender(anetz_t *anetz, double page_gain, int page_sequence)
for (i = 0; i < 2; i++) for (i = 0; i < 2; i++)
audio_goertzel_init(&anetz->fsk_tone_goertzel[i], fsk_tones[i], anetz->sender.samplerate); audio_goertzel_init(&anetz->fsk_tone_goertzel[i], fsk_tones[i], anetz->sender.samplerate);
tone = fsk_tones[(anetz->sender.loopback == 0) ? 0 : 1]; tone = fsk_tones[(anetz->sender.loopback == 0) ? 0 : 1];
anetz->tone_phaseshift256 = 256.0 / ((double)anetz->sender.samplerate / tone); anetz->tone_phaseshift65536 = 65536.0 / ((double)anetz->sender.samplerate / tone);
PDEBUG(DDSP, DEBUG_DEBUG, "TX %.0f Hz phaseshift = %.4f\n", tone, anetz->tone_phaseshift256); PDEBUG(DDSP, DEBUG_DEBUG, "TX %.0f Hz phaseshift = %.4f\n", tone, anetz->tone_phaseshift65536);
return 0; return 0;
} }
@ -169,19 +165,19 @@ static void fsk_decode_chunk(anetz_t *anetz, sample_t *spl, int max)
/* show quality of tone */ /* show quality of tone */
if (anetz->sender.loopback) { if (anetz->sender.loopback) {
/* adjust level, so we get peak of sine curve */ /* adjust level, so we get peak of sine curve */
PDEBUG_CHAN(DDSP, DEBUG_NOTICE, "Tone %.0f: Level=%3.0f%% Quality=%3.0f%%\n", fsk_tones[1], level / 0.63662 * 100.0 * 32768.0 / TX_PEAK_TONE, result[1] / level * 100.0); PDEBUG_CHAN(DDSP, DEBUG_NOTICE, "Tone %.0f: Level=%3.0f%% Quality=%3.0f%%\n", fsk_tones[1], level / 0.63662 * 100.0 / TX_PEAK_TONE, result[1] / level * 100.0);
} }
if (level / 0.63 > 0.05 && result[0] / level > 0.5) if (level / 0.63 > 0.05 && result[0] / level > 0.5)
PDEBUG_CHAN(DDSP, DEBUG_INFO, "Tone %.0f: Level=%3.0f%% Quality=%3.0f%%\n", fsk_tones[0], level / 0.63662 * 100.0 * 32768.0 / TX_PEAK_TONE, result[0] / level * 100.0); PDEBUG_CHAN(DDSP, DEBUG_INFO, "Tone %.0f: Level=%3.0f%% Quality=%3.0f%%\n", fsk_tones[0], level / 0.63662 * 100.0 / TX_PEAK_TONE, result[0] / level * 100.0);
/* adjust level, so we get peak of sine curve */ /* adjust level, so we get peak of sine curve */
/* indicate detected tone */ /* indicate detected tone */
if (level / 0.63 > 0.05 && result[0] / level > 0.5) if (level / 0.63 > 0.05 && result[0] / level > 0.5)
fsk_receive_tone(anetz, 0, 1, level / 0.63662 * 32768.0 / TX_PEAK_TONE); fsk_receive_tone(anetz, 0, 1, level / 0.63662 / TX_PEAK_TONE);
else if (level / 0.63 > 0.05 && result[1] / level > 0.5) else if (level / 0.63 > 0.05 && result[1] / level > 0.5)
fsk_receive_tone(anetz, 1, 1, level / 0.63662 * 32768.0 / TX_PEAK_TONE); fsk_receive_tone(anetz, 1, 1, level / 0.63662 / TX_PEAK_TONE);
else else
fsk_receive_tone(anetz, -1, 0, level / 0.63662 * 32768.0 / TX_PEAK_TONE); fsk_receive_tone(anetz, -1, 0, level / 0.63662 / TX_PEAK_TONE);
} }
/* Process received audio stream from radio unit. */ /* Process received audio stream from radio unit. */
@ -230,42 +226,36 @@ void dsp_set_paging(anetz_t *anetz, double *freq)
int i; int i;
for (i = 0; i < 4; i++) { for (i = 0; i < 4; i++) {
anetz->paging_phaseshift256[i] = 256.0 / ((double)anetz->sender.samplerate / freq[i]); anetz->paging_phaseshift65536[i] = 65536.0 / ((double)anetz->sender.samplerate / freq[i]);
anetz->paging_phase256[i] = 0; anetz->paging_phase65536[i] = 0;
} }
} }
/* Generate audio stream of 4 simultanious paging tones. Keep phase for next call of function. /* Generate audio stream of 4 simultanious paging tones. Keep phase for next call of function.
* Use TX_PEAK_TONE*page_gain for all tones, which gives peak of 1/4th for each individual tone. */ * Use TX_PEAK_PAGE*page_gain for all tones, which gives peak of 1/4th for each individual tone. */
static void fsk_paging_tone(anetz_t *anetz, sample_t *samples, int length) static void fsk_paging_tone(anetz_t *anetz, sample_t *samples, int length)
{ {
double phaseshift[4], phase[4]; double *phaseshift, *phase;
int i; int i;
double sample; double sample;
for (i = 0; i < 4; i++) { phaseshift = anetz->paging_phaseshift65536;
phaseshift[i] = anetz->paging_phaseshift256[i]; phase = anetz->paging_phase65536;
phase[i] = anetz->paging_phase256[i];
}
for (i = 0; i < length; i++) { for (i = 0; i < length; i++) {
sample = (int32_t)dsp_sine_tone[(uint8_t)phase[0]] sample = dsp_sine_page[(uint16_t)phase[0]]
+ (int32_t)dsp_sine_tone[(uint8_t)phase[1]] + dsp_sine_page[(uint16_t)phase[1]]
+ (int32_t)dsp_sine_tone[(uint8_t)phase[2]] + dsp_sine_page[(uint16_t)phase[2]]
+ (int32_t)dsp_sine_tone[(uint8_t)phase[3]]; + dsp_sine_page[(uint16_t)phase[3]];
*samples++ = sample / 4.0 * anetz->page_gain; *samples++ = sample / 4.0 * anetz->page_gain;
phase[0] += phaseshift[0]; phase[0] += phaseshift[0];
phase[1] += phaseshift[1]; phase[1] += phaseshift[1];
phase[2] += phaseshift[2]; phase[2] += phaseshift[2];
phase[3] += phaseshift[3]; phase[3] += phaseshift[3];
if (phase[0] >= 256) phase[0] -= 256; if (phase[0] >= 65536) phase[0] -= 65536;
if (phase[1] >= 256) phase[1] -= 256; if (phase[1] >= 65536) phase[1] -= 65536;
if (phase[2] >= 256) phase[2] -= 256; if (phase[2] >= 65536) phase[2] -= 65536;
if (phase[3] >= 256) phase[3] -= 256; if (phase[3] >= 65536) phase[3] -= 65536;
}
for (i = 0; i < 4; i++) {
anetz->paging_phase256[i] = phase[i];
} }
} }
@ -280,14 +270,11 @@ static void fsk_paging_tone(anetz_t *anetz, sample_t *samples, int length)
*/ */
static void fsk_paging_tone_sequence(anetz_t *anetz, sample_t *samples, int length, int numspl) static void fsk_paging_tone_sequence(anetz_t *anetz, sample_t *samples, int length, int numspl)
{ {
double phaseshift[4], phase[4]; double *phaseshift, *phase;
int i;
int tone, count, transition; int tone, count, transition;
for (i = 0; i < 4; i++) { phaseshift = anetz->paging_phaseshift65536;
phaseshift[i] = anetz->paging_phaseshift256[i]; phase = anetz->paging_phase65536;
phase[i] = anetz->paging_phase256[i];
}
tone = anetz->paging_tone; tone = anetz->paging_tone;
count = anetz->paging_count; count = anetz->paging_count;
transition = anetz->paging_transition; transition = anetz->paging_transition;
@ -295,21 +282,21 @@ static void fsk_paging_tone_sequence(anetz_t *anetz, sample_t *samples, int leng
while (length) { while (length) {
/* use tone, but during transition of tones, keep phase 0 degrees (high level) until next tone reaches 0 degrees (high level) */ /* use tone, but during transition of tones, keep phase 0 degrees (high level) until next tone reaches 0 degrees (high level) */
if (!transition) if (!transition)
*samples++ = dsp_sine_tone[(uint8_t)phase[tone]] * anetz->page_gain; *samples++ = dsp_sine_page[(uint16_t)phase[tone]] * anetz->page_gain;
else { else {
/* fade between old an new tone */ /* fade between old an new tone */
*samples++ *samples++
= (double)dsp_sine_tone[(uint8_t)phase[(tone - 1) & 3]] * (double)(transition - count) / (double)transition / 2.0 * anetz->page_gain = (double)dsp_sine_page[(uint16_t)phase[(tone - 1) & 3]] * (double)(transition - count) / (double)transition / 2.0 * anetz->page_gain
+ (double)dsp_sine_tone[(uint8_t)phase[tone]] * (double)count / (double)transition / 2.0 * anetz->page_gain; + (double)dsp_sine_page[(uint16_t)phase[tone]] * (double)count / (double)transition / 2.0 * anetz->page_gain;
} }
phase[0] += phaseshift[0]; phase[0] += phaseshift[0];
phase[1] += phaseshift[1]; phase[1] += phaseshift[1];
phase[2] += phaseshift[2]; phase[2] += phaseshift[2];
phase[3] += phaseshift[3]; phase[3] += phaseshift[3];
if (phase[0] >= 256) phase[0] -= 256; if (phase[0] >= 65536) phase[0] -= 65536;
if (phase[1] >= 256) phase[1] -= 256; if (phase[1] >= 65536) phase[1] -= 65536;
if (phase[2] >= 256) phase[2] -= 256; if (phase[2] >= 65536) phase[2] -= 65536;
if (phase[3] >= 256) phase[3] -= 256; if (phase[3] >= 65536) phase[3] -= 65536;
count++; count++;
if (transition && count == transition) { if (transition && count == transition) {
transition = 0; transition = 0;
@ -327,9 +314,6 @@ static void fsk_paging_tone_sequence(anetz_t *anetz, sample_t *samples, int leng
length--; length--;
} }
for (i = 0; i < 4; i++) {
anetz->paging_phase256[i] = phase[i];
}
anetz->paging_tone = tone; anetz->paging_tone = tone;
anetz->paging_count = count; anetz->paging_count = count;
anetz->paging_transition = transition; anetz->paging_transition = transition;
@ -341,17 +325,17 @@ static void fsk_tone(anetz_t *anetz, sample_t *samples, int length)
double phaseshift, phase; double phaseshift, phase;
int i; int i;
phaseshift = anetz->tone_phaseshift256; phaseshift = anetz->tone_phaseshift65536;
phase = anetz->tone_phase256; phase = anetz->tone_phase65536;
for (i = 0; i < length; i++) { for (i = 0; i < length; i++) {
*samples++ = dsp_sine_tone[(uint8_t)phase]; *samples++ = dsp_sine_tone[(uint16_t)phase];
phase += phaseshift; phase += phaseshift;
if (phase >= 256) if (phase >= 65536)
phase -= 256; phase -= 65536;
} }
anetz->tone_phase256 = phase; anetz->tone_phase65536 = phase;
} }
/* Provide stream of audio toward radio unit */ /* Provide stream of audio toward radio unit */

View File

@ -88,8 +88,8 @@ typedef struct bnetz {
int fsk_filter_qualidx; /* index of quality array above */ int fsk_filter_qualidx; /* index of quality array above */
int tone_detected; /* what tone has been detected */ int tone_detected; /* what tone has been detected */
int tone_count; /* how long has that tone been detected */ int tone_count; /* how long has that tone been detected */
double phaseshift256[2]; /* how much the phase of sine wave changes per sample */ double phaseshift65536[2]; /* how much the phase of sine wave changes per sample */
double phase256; /* current phase */ double phase65536; /* current phase */
int telegramm; /* set, if there is a valid telegram */ int telegramm; /* set, if there is a valid telegram */
sample_t *telegramm_spl; /* 16 * samples_per_bit */ sample_t *telegramm_spl; /* 16 * samples_per_bit */
int telegramm_pos; /* current sample position in telegramm_spl */ int telegramm_pos; /* current sample position in telegramm_spl */

View File

@ -34,9 +34,19 @@
#define PI 3.1415927 #define PI 3.1415927
/* Notes on TX_PEAK_TONE level:
*
* At 2000 Hz the deviation shall be 4 kHz, so with emphasis the deviation
* at 1000 Hz would be theoretically 2 kHz. This is factor 0.714 below
* 2.8 kHz deviation we want at dBm0.
*/
/* signaling */ /* signaling */
#define BANDWIDTH 5000.0 /* maximum bandwidth */ #define MAX_DEVIATION 4000.0
#define TX_PEAK_TONE 5000.0 /* peak amplitude for all tones */ #define MAX_MODULATION 3000.0
#define DBM0_DEVIATION 2800.0 /* deviation of dBm0 at 1 kHz */
#define TX_PEAK_TONE (4000.0 / 2000.0 * 1000.0 / DBM0_DEVIATION)
#define MAX_DISPLAY 1.4 /* something above dBm0 */
#define BIT_DURATION 0.010 /* bit length: 10 ms */ #define BIT_DURATION 0.010 /* bit length: 10 ms */
#define FILTER_STEP 0.001 /* step every 1 ms */ #define FILTER_STEP 0.001 /* step every 1 ms */
#define METERING_HZ 2900 /* metering pulse frequency */ #define METERING_HZ 2900 /* metering pulse frequency */
@ -54,7 +64,7 @@ static double fsk_bits[2] = {
}; };
/* table for fast sine generation */ /* table for fast sine generation */
static sample_t dsp_sine[256]; static sample_t dsp_sine[65536];
/* global init for FSK */ /* global init for FSK */
void dsp_init(void) void dsp_init(void)
@ -62,13 +72,8 @@ void dsp_init(void)
int i; int i;
PDEBUG(DDSP, DEBUG_DEBUG, "Generating sine table.\n"); PDEBUG(DDSP, DEBUG_DEBUG, "Generating sine table.\n");
for (i = 0; i < 256; i++) { for (i = 0; i < 65536; i++) {
dsp_sine[i] = (int)(sin((double)i / 256.0 * 2.0 * PI) * TX_PEAK_TONE); dsp_sine[i] = sin((double)i / 65536.0 * 2.0 * PI) * TX_PEAK_TONE;
}
if (TX_PEAK_TONE > 32767.0) {
fprintf(stderr, "TX_PEAK_TONE definition too high, please fix!\n");
abort();
} }
} }
@ -85,9 +90,8 @@ int dsp_init_sender(bnetz_t *bnetz)
PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Init DSP for 'Sender'.\n"); PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Init DSP for 'Sender'.\n");
/* set deviation and modulation parameters */ /* set modulation parameters */
bnetz->sender.bandwidth = BANDWIDTH; sender_set_fm(&bnetz->sender, MAX_DEVIATION, MAX_MODULATION, DBM0_DEVIATION, MAX_DISPLAY);
bnetz->sender.sample_deviation = 1250.0 / (double)TX_PEAK_TONE; // FIXME: calc real value
audio_init_loss(&bnetz->sender.loss, LOSS_INTERVAL, bnetz->sender.loss_volume, LOSS_TIME); audio_init_loss(&bnetz->sender.loss, LOSS_INTERVAL, bnetz->sender.loss_volume, LOSS_TIME);
@ -114,8 +118,8 @@ int dsp_init_sender(bnetz_t *bnetz)
/* count symbols */ /* count symbols */
for (i = 0; i < 2; i++) { for (i = 0; i < 2; i++) {
audio_goertzel_init(&bnetz->fsk_goertzel[i], fsk_bits[i], bnetz->sender.samplerate); audio_goertzel_init(&bnetz->fsk_goertzel[i], fsk_bits[i], bnetz->sender.samplerate);
bnetz->phaseshift256[i] = 256.0 / ((double)bnetz->sender.samplerate / fsk_bits[i]); bnetz->phaseshift65536[i] = 65536.0 / ((double)bnetz->sender.samplerate / fsk_bits[i]);
PDEBUG(DDSP, DEBUG_DEBUG, "phaseshift[%d] = %.4f (must be arround 64 at 8000hz)\n", i, bnetz->phaseshift256[i]); PDEBUG(DDSP, DEBUG_DEBUG, "phaseshift[%d] = %.4f (must be arround 64 at 8000hz)\n", i, bnetz->phaseshift65536[i]);
} }
return 0; return 0;
@ -241,9 +245,9 @@ static inline void fsk_decode_step(bnetz_t *bnetz, int pos)
// FIXME: better threshold // FIXME: better threshold
/* adjust level, so we get peak of sine curve */ /* adjust level, so we get peak of sine curve */
if (level / 0.63 > 0.05 && (softbit > 0.75 || softbit < 0.25)) { if (level / 0.63 > 0.05 && (softbit > 0.75 || softbit < 0.25)) {
fsk_receive_tone(bnetz, bit, 1, level / 0.63662 * 32768.0 / TX_PEAK_TONE, quality); fsk_receive_tone(bnetz, bit, 1, level / 0.63662 / TX_PEAK_TONE, quality);
} else } else
fsk_receive_tone(bnetz, bit, 0, level / 0.63662 * 32768.0 / TX_PEAK_TONE, quality); fsk_receive_tone(bnetz, bit, 0, level / 0.63662 / TX_PEAK_TONE, quality);
if (bnetz->fsk_filter_bit != bit) { if (bnetz->fsk_filter_bit != bit) {
/* if we have a bit change, reset sample counter to one half bit duration */ /* if we have a bit change, reset sample counter to one half bit duration */
@ -256,7 +260,7 @@ static inline void fsk_decode_step(bnetz_t *bnetz, int pos)
printf("|%s|\n", debug_amplitude(quality); printf("|%s|\n", debug_amplitude(quality);
#endif #endif
/* adjust level, so we get peak of sine curve */ /* adjust level, so we get peak of sine curve */
fsk_receive_bit(bnetz, bit, level / 0.63662 * 32768.0 / TX_PEAK_TONE, quality); fsk_receive_bit(bnetz, bit, level / 0.63662 / TX_PEAK_TONE, quality);
bnetz->fsk_filter_sample = 10; bnetz->fsk_filter_sample = 10;
} }
} }
@ -308,17 +312,17 @@ static void fsk_tone(bnetz_t *bnetz, sample_t *samples, int length, int tone)
double phaseshift, phase; double phaseshift, phase;
int i; int i;
phase = bnetz->phase256; phase = bnetz->phase65536;
phaseshift = bnetz->phaseshift256[tone]; phaseshift = bnetz->phaseshift65536[tone];
for (i = 0; i < length; i++) { for (i = 0; i < length; i++) {
*samples++ = dsp_sine[(uint8_t)phase]; *samples++ = dsp_sine[(uint16_t)phase];
phase += phaseshift; phase += phaseshift;
if (phase >= 256) if (phase >= 65536)
phase -= 256; phase -= 65536;
} }
bnetz->phase256 = phase; bnetz->phase65536 = phase;
} }
static int fsk_telegramm(bnetz_t *bnetz, sample_t *samples, int length) static int fsk_telegramm(bnetz_t *bnetz, sample_t *samples, int length)
@ -342,17 +346,17 @@ next_telegramm:
bnetz->telegramm_pos = 0; bnetz->telegramm_pos = 0;
spl = bnetz->telegramm_spl; spl = bnetz->telegramm_spl;
/* render telegramm */ /* render telegramm */
phase = bnetz->phase256; phase = bnetz->phase65536;
for (i = 0; i < 16; i++) { for (i = 0; i < 16; i++) {
phaseshift = bnetz->phaseshift256[telegramm[i] == '1']; phaseshift = bnetz->phaseshift65536[telegramm[i] == '1'];
for (j = 0; j < bnetz->samples_per_bit; j++) { for (j = 0; j < bnetz->samples_per_bit; j++) {
*spl++ = dsp_sine[(uint8_t)phase]; *spl++ = dsp_sine[(uint16_t)phase];
phase += phaseshift; phase += phaseshift;
if (phase >= 256) if (phase >= 65536)
phase -= 256; phase -= 65536;
} }
} }
bnetz->phase256 = phase; bnetz->phase65536 = phase;
} }
/* send audio from telegramm */ /* send audio from telegramm */

View File

@ -43,9 +43,12 @@ extern int voice_deviation;
#define PI M_PI #define PI M_PI
#define BANDWIDTH 5500.0 /* maximum bandwidth */ #define MAX_DEVIATION 4000.0
#define FSK_DEVIATION 10000 #define MAX_MODULATION 5280.0
#define COMPANDOR_0DB 30000 #define DBM0_DEVIATION 4000.0 /* deviation of dBm0 at 1 kHz */
#define COMPANDOR_0DB 1.0 /* A level of 0dBm (1.0) shall be unaccected */
#define FSK_DEVIATION (2500.0 / DBM0_DEVIATION) /* no emphasis */
#define MAX_DISPLAY 1.4 /* something above dBm0, no emphasis */
#define BITRATE 5280.0 /* bits per second */ #define BITRATE 5280.0 /* bits per second */
#define BLOCK_BITS 198 /* duration of one time slot including pause at beginning and end */ #define BLOCK_BITS 198 /* duration of one time slot including pause at beginning and end */
#define CUT_OFF_OFFSET 300.0 /* cut off frequency for offset filter (level correction between subsequent audio chunks) */ #define CUT_OFF_OFFSET 300.0 /* cut off frequency for offset filter (level correction between subsequent audio chunks) */
@ -76,7 +79,7 @@ static void dsp_init_ramp(cnetz_t *cnetz)
c = -sqrt(-c); c = -sqrt(-c);
else else
c = sqrt(c); c = sqrt(c);
ramp_down[i] = (int)(c * (double)cnetz->fsk_deviation); ramp_down[i] = c * (double)cnetz->fsk_deviation;
ramp_up[i] = -ramp_down[i]; ramp_up[i] = -ramp_down[i];
} }
} }
@ -90,9 +93,8 @@ int dsp_init_sender(cnetz_t *cnetz, int measure_speed, double clock_speed[2], do
PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Init FSK for 'Sender'.\n"); PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Init FSK for 'Sender'.\n");
/* set deviation and modulation parameters */ /* set modulation parameters */
cnetz->sender.bandwidth = BANDWIDTH; sender_set_fm(&cnetz->sender, MAX_DEVIATION, MAX_MODULATION, DBM0_DEVIATION, MAX_DISPLAY);
cnetz->sender.sample_deviation = 2500.0 / (double)FSK_DEVIATION;
if (measure_speed) { if (measure_speed) {
cnetz->measure_speed = measure_speed; cnetz->measure_speed = measure_speed;
@ -119,7 +121,7 @@ int dsp_init_sender(cnetz_t *cnetz, int measure_speed, double clock_speed[2], do
} }
/* create devation and ramp */ /* create devation and ramp */
cnetz->fsk_deviation = FSK_DEVIATION; /* be sure not to overflow -32767 .. 32767 */ cnetz->fsk_deviation = FSK_DEVIATION;
dsp_init_ramp(cnetz); dsp_init_ramp(cnetz);
cnetz->fsk_noise = noise; cnetz->fsk_noise = noise;
@ -465,7 +467,7 @@ static int fsk_distributed_encode(cnetz_t *cnetz, const char *bits)
} while (phase < 256.0); } while (phase < 256.0);
phase -= 256.0; phase -= 256.0;
} }
*marker = -32768; /* indicator for inserting speech */ *marker = 999; /* marker for inserting speech */
} }
/* add 46 * (1+4+1 + 60) bits */ /* add 46 * (1+4+1 + 60) bits */
for (i = 0; i < 46; i++) { for (i = 0; i < 46; i++) {
@ -556,7 +558,7 @@ static int fsk_distributed_encode(cnetz_t *cnetz, const char *bits)
} while (phase < 256.0); } while (phase < 256.0);
phase -= 256.0; phase -= 256.0;
} }
*marker = -32768; /* indicator for inserting speech */ *marker = 999; /* marker for inserting speech */
} }
/* depending on the number of samples, return the number */ /* depending on the number of samples, return the number */
@ -706,7 +708,7 @@ again:
if (length - count < copy) if (length - count < copy)
copy = length - count; copy = length - count;
for (i = 0; i < copy; i++) { for (i = 0; i < copy; i++) {
if (*spl == -32768) { if (*spl == 999) {
/* marker found to insert new chunk of audio */ /* marker found to insert new chunk of audio */
jitter_load(&cnetz->sender.dejitter, speech_buffer, 100); jitter_load(&cnetz->sender.dejitter, speech_buffer, 100);
/* 1. compress dynamics */ /* 1. compress dynamics */
@ -722,15 +724,9 @@ again:
pre_emphasis(&cnetz->estate, speech_buffer, speech_length); pre_emphasis(&cnetz->estate, speech_buffer, speech_length);
/* change level */ /* change level */
if (voice_deviation != 1) { if (voice_deviation != 1) {
int sample, j; int j;
for (j = 0; j < speech_length; j++) { for (j = 0; j < speech_length; j++)
sample = speech_buffer[j] * voice_deviation; speech_buffer[j] *= (double)voice_deviation;
if (sample > 32767)
sample = 32767;
if (sample < -32768)
sample = -32768;
speech_buffer[j] = sample;
}
} }
speech_pos = 0; speech_pos = 0;
} }
@ -801,7 +797,7 @@ void unshrink_speech(cnetz_t *cnetz, sample_t *speech_buffer, int count)
factor = cnetz->offset_factor; factor = cnetz->offset_factor;
for (i = 0; i < count; i++) { for (i = 0; i < count; i++) {
/* change level */ /* change level */
x = speech_buffer[i] / voice_deviation; x = speech_buffer[i] / (double)voice_deviation;
/* high-pass to remove low level frequencies, caused by level jump between audio chunks */ /* high-pass to remove low level frequencies, caused by level jump between audio chunks */
y = factor * (y_last + x - x_last); y = factor * (y_last + x - x_last);
x_last = x; x_last = x;

View File

@ -148,7 +148,7 @@ int fsk_fm_init(fsk_fm_demod_t *fsk, cnetz_t *cnetz, int samplerate, double bitr
goto error; goto error;
} }
fsk->level_threshold = 655; fsk->level_threshold = 0.1;
return 0; return 0;
@ -170,9 +170,10 @@ void fsk_fm_exit(fsk_fm_demod_t *fsk)
} }
/* get levels, sync time and jitter from sync sequence or frame data */ /* get levels, sync time and jitter from sync sequence or frame data */
static inline void get_levels(fsk_fm_demod_t *fsk, int *_min, int *_max, int *_avg, int *_probes, int num, double *_time, double *_jitter) static inline void get_levels(fsk_fm_demod_t *fsk, double *_min, double *_max, double *_avg, int *_probes, int num, double *_time, double *_jitter)
{ {
int min = 32767, max = -32768, avg = 0, count = 0, level; int count = 0;
double min = 0, max = 0, avg = 0, level;
double time = 0, t, sync_average, sync_time, jitter = 0; double time = 0, t, sync_average, sync_time, jitter = 0;
int bit_offset; int bit_offset;
int i; int i;
@ -192,19 +193,20 @@ static inline void get_levels(fsk_fm_demod_t *fsk, int *_min, int *_max, int *_a
if (t > BITS_PER_SUPERFRAME / 2) if (t > BITS_PER_SUPERFRAME / 2)
t -= BITS_PER_SUPERFRAME; t -= BITS_PER_SUPERFRAME;
//if (fsk->cnetz->dsp_mode == DSP_MODE_SPK_V) //if (fsk->cnetz->dsp_mode == DSP_MODE_SPK_V)
// printf("%d: level=%d%% @%.2f difference=%.2f\n", bit_offset, level * 100 / 65536, fsk->change_when[(fsk->change_pos - 1 - i) & 0xff], t); // printf("%d: level=%.0f%% @%.2f difference=%.2f\n", bit_offset, level * 100, fsk->change_when[(fsk->change_pos - 1 - i) & 0xff], t);
time += t; time += t;
if (level < min) if (i == 0 || level < min)
min = level; min = level;
if (level > max) if (i == 0 || level > max)
max = level; max = level;
avg += level; avg += level;
count++; count++;
} }
/* should never happen */
if (!count) { if (!count) {
*_min = *_max = *_avg = 0; *_min = *_max = *_avg = 0.0;
return; return;
} }
@ -219,7 +221,7 @@ static inline void get_levels(fsk_fm_demod_t *fsk, int *_min, int *_max, int *_a
*_probes = count; *_probes = count;
*_min = min; *_min = min;
*_max = max; *_max = max;
*_avg = avg / count; *_avg = avg / (double)count;
if (_time) { if (_time) {
// if (fsk->cnetz->dsp_mode == DSP_MODE_SPK_V) // if (fsk->cnetz->dsp_mode == DSP_MODE_SPK_V)
@ -254,15 +256,16 @@ static inline void get_levels(fsk_fm_demod_t *fsk, int *_min, int *_max, int *_a
} }
} }
static inline void got_bit(fsk_fm_demod_t *fsk, int bit, int change_level) static inline void got_bit(fsk_fm_demod_t *fsk, int bit, double change_level)
{ {
int min, max, avg, probes; int probes;
double min, max, avg;
/* count bits, but do not exceed 4 bits per SPK block */ /* count bits, but do not exceed 4 bits per SPK block */
if (fsk->cnetz->dsp_mode == DSP_MODE_SPK_V) { if (fsk->cnetz->dsp_mode == DSP_MODE_SPK_V) {
/* for first bit, we have only half of the modulation deviation, so we multiply level by two */ /* for first bit, we have only half of the modulation deviation, so we multiply level by two */
if (fsk->bit_count == 0) if (fsk->bit_count == 0)
change_level *= 2; change_level *= 2.0;
if (fsk->bit_count == 4) if (fsk->bit_count == 4)
return; return;
} }
@ -284,20 +287,20 @@ static inline void got_bit(fsk_fm_demod_t *fsk, int bit, int change_level)
* for all other bits in the sync sequence. * for all other bits in the sync sequence.
* after sync, the theshold is set to half of the average of * after sync, the theshold is set to half of the average of
* all changes in the sync sequence */ * all changes in the sync sequence */
if (change_level) { if (change_level > 0.0) {
fsk->level_threshold = (double)change_level / 2.0; fsk->level_threshold = change_level / 2.0;
} else if ((fsk->rx_sync & 0x1f) == 0x00 || (fsk->rx_sync & 0x1f) == 0x1f) { } else if ((fsk->rx_sync & 0x1f) == 0x00 || (fsk->rx_sync & 0x1f) == 0x1f) {
if (fsk->cnetz->dsp_mode != DSP_MODE_SPK_V) if (fsk->cnetz->dsp_mode != DSP_MODE_SPK_V)
fsk->level_threshold = 655; fsk->level_threshold = 0.01;
} }
if (detect_sync(fsk->rx_sync)) { if (detect_sync(fsk->rx_sync)) {
fsk->sync = FSK_SYNC_POSITIVE; fsk->sync = FSK_SYNC_POSITIVE;
got_sync: got_sync:
get_levels(fsk, &min, &max, &avg, &probes, 30, &fsk->sync_time, &fsk->sync_jitter); get_levels(fsk, &min, &max, &avg, &probes, 30, &fsk->sync_time, &fsk->sync_jitter);
fsk->sync_level = (double)avg / 65535.0; fsk->sync_level = avg / 2.0;
if (fsk->sync == FSK_SYNC_NEGATIVE) if (fsk->sync == FSK_SYNC_NEGATIVE)
fsk->sync_level = -fsk->sync_level; fsk->sync_level = -fsk->sync_level;
// printf("sync (change min=%d%% max=%d%% avg=%d%% sync_time=%.2f jitter=%.2f probes=%d)\n", min * 100 / 65535, max * 100 / 65535, avg * 100 / 65535, fsk->sync_time, fsk->sync_jitter, probes); // printf("sync (change min=%.0f%% max=%.0f%% avg=%.0f%% sync_time=%.2f jitter=%.2f probes=%d)\n", min * 100, max * 100, avg * 100, fsk->sync_time, fsk->sync_jitter, probes);
fsk->level_threshold = (double)avg / 2.0; fsk->level_threshold = (double)avg / 2.0;
fsk->rx_sync = 0; fsk->rx_sync = 0;
fsk->rx_buffer_count = 0; fsk->rx_buffer_count = 0;
@ -342,6 +345,10 @@ static inline void find_change(fsk_fm_demod_t *fsk)
change_at = -1; change_at = -1;
change_positive = -1; change_positive = -1;
/* get level range (level_min and level_max) and also
* get maximum slope (change_max) and where it was
* (change_at) and what direction it went (change_positive)
*/
for (i = 0; i < fsk->bit_buffer_len; i++) { for (i = 0; i < fsk->bit_buffer_len; i++) {
last_s = s; last_s = s;
s = fsk->bit_buffer_spl[fsk->bit_buffer_pos++]; s = fsk->bit_buffer_spl[fsk->bit_buffer_pos++];
@ -417,7 +424,7 @@ void fsk_fm_demod(fsk_fm_demod_t *fsk, sample_t *samples, int length)
if (fsk->cnetz->dsp_mode != DSP_MODE_SPK_V) { if (fsk->cnetz->dsp_mode != DSP_MODE_SPK_V) {
#ifdef DEBUG_DECODER #ifdef DEBUG_DECODER
DEBUG_DECODER DEBUG_DECODER
puts(debug_amplitude(samples[i] / 32768.0)); puts(debug_amplitude(samples[i]));
#endif #endif
find_change(fsk); find_change(fsk);
} else { } else {
@ -441,7 +448,7 @@ void fsk_fm_demod(fsk_fm_demod_t *fsk, sample_t *samples, int length)
if (t >= 0.5 && t < 5.5) { if (t >= 0.5 && t < 5.5) {
#ifdef DEBUG_DECODER #ifdef DEBUG_DECODER
DEBUG_DECODER DEBUG_DECODER
puts(debug_amplitude(samples[i] / 32768.0)); puts(debug_amplitude(samples[i]));
#endif #endif
find_change(fsk); find_change(fsk);
} else } else

View File

@ -24,7 +24,7 @@ typedef struct fsk_fm_demod {
int bit_buffer_len; /* number of samples in ring buffer */ int bit_buffer_len; /* number of samples in ring buffer */
int bit_buffer_half; /* half of ring buffer */ int bit_buffer_half; /* half of ring buffer */
int bit_buffer_pos; /* current position to write next sample */ int bit_buffer_pos; /* current position to write next sample */
int level_threshold; /* threshold for detection of next level change */ double level_threshold; /* threshold for detection of next level change */
double bits_per_sample; /* duration of one sample in bits */ double bits_per_sample; /* duration of one sample in bits */
double next_bit; /* count time to detect bits */ double next_bit; /* count time to detect bits */
int bit_count; /* counts bits, to match 4 bits at distributed signaling */ int bit_count; /* counts bits, to match 4 bits at distributed signaling */
@ -45,7 +45,7 @@ typedef struct fsk_fm_demod {
int rx_buffer_count; /* counter when receiving bits */ int rx_buffer_count; /* counter when receiving bits */
/* statistics */ /* statistics */
int change_levels[256]; /* ring buffer to store levels */ double change_levels[256]; /* ring buffer to store levels */
double change_when[256]; /* ring buffer to store time when level has changed */ double change_when[256]; /* ring buffer to store time when level has changed */
uint8_t change_pos; /* index for next write */ uint8_t change_pos; /* index for next write */
} fsk_fm_demod_t; } fsk_fm_demod_t;

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@ -36,22 +36,22 @@
#define TEST_1000HZ_DB 55.0 #define TEST_1000HZ_DB 55.0
/* sine wave for carrier to modulate to */ /* sine wave for carrier to modulate to */
static double carrier[256]; static double carrier[65536];
void scrambler_init(void) void scrambler_init(void)
{ {
int i; int i;
for (i = 0; i < 256; i++) { for (i = 0; i < 65536; i++) {
/* our amplitude must be doubled, since we have one spectrum above and one below carrier */ /* our amplitude must be doubled, since we have one spectrum above and one below carrier */
carrier[i] = sin((double)i / 256.0 * 2 * PI) * 2.0; carrier[i] = sin((double)i / 65536.0 * 2 * PI) * 2.0;
} }
} }
void scrambler_setup(scrambler_t *scrambler, int samplerate) void scrambler_setup(scrambler_t *scrambler, int samplerate)
{ {
filter_lowpass_init(&scrambler->lp, CARRIER_HZ - FILTER_BELOW, samplerate, FILTER_TURNS); filter_lowpass_init(&scrambler->lp, CARRIER_HZ - FILTER_BELOW, samplerate, FILTER_TURNS);
scrambler->carrier_phaseshift256 = 256.0 / ((double)samplerate / CARRIER_HZ); scrambler->carrier_phaseshift65536 = 65536.0 / ((double)samplerate / CARRIER_HZ);
} }
/* Modulate samples to carriere that is twice the mirror frequency. /* Modulate samples to carriere that is twice the mirror frequency.
@ -63,18 +63,18 @@ void scrambler(scrambler_t *scrambler, sample_t *samples, int length)
double phaseshift, phase; double phaseshift, phase;
int i; int i;
phaseshift = scrambler->carrier_phaseshift256; phaseshift = scrambler->carrier_phaseshift65536;
phase = scrambler->carrier_phase256; phase = scrambler->carrier_phase65536;
for (i = 0; i < length; i++) { for (i = 0; i < length; i++) {
/* modulate samples to carrier */ /* modulate samples to carrier */
samples[i] *= carrier[((uint8_t)phase) & 0xff]; samples[i] *= carrier[(uint16_t)phase];
phase += phaseshift; phase += phaseshift;
if (phase >= 256.0) if (phase >= 65536.0)
phase -= 256.0; phase -= 65536.0;
} }
scrambler->carrier_phase256 = phase; scrambler->carrier_phase65536 = phase;
/* cut off carrier frequency and modulation above carrier frequency */ /* cut off carrier frequency and modulation above carrier frequency */
filter_process(&scrambler->lp, samples, length); filter_process(&scrambler->lp, samples, length);

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@ -1,8 +1,8 @@
#include "../common/filter.h" #include "../common/filter.h"
typedef struct scrambler { typedef struct scrambler {
double carrier_phaseshift256; /* carrier phase shift per sample */ double carrier_phaseshift65536;/* carrier phase shift per sample */
double carrier_phase256; /* current phase of carrier frequency */ double carrier_phase65536; /* current phase of carrier frequency */
filter_t lp; /* filter to remove carrier frequency */ filter_t lp; /* filter to remove carrier frequency */
} scrambler_t; } scrambler_t;

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@ -1492,9 +1492,9 @@ void cnetz_decode_telegramm(cnetz_t *cnetz, const char *bits, double level, doub
telegramm.jitter = jitter; telegramm.jitter = jitter;
if (bit_errors) if (bit_errors)
PDEBUG_CHAN(DDSP, DEBUG_INFO, "RX Level: %.0f%% Jitter: %.2f Sync Time: %.2f (TS %.2f) Bit errors: %d %s\n", fabs(level) * 32767.0 / cnetz->fsk_deviation * 100.0, jitter, sync_time, sync_time / 396.0, bit_errors, (level < 0) ? "NEGATIVE (phone's mode)" : "POSITIVE (base station's mode)"); PDEBUG_CHAN(DDSP, DEBUG_INFO, "RX Level: %.0f%% Jitter: %.2f Sync Time: %.2f (TS %.2f) Bit errors: %d %s\n", fabs(level) / cnetz->fsk_deviation * 100.0, jitter, sync_time, sync_time / 396.0, bit_errors, (level < 0) ? "NEGATIVE (phone's mode)" : "POSITIVE (base station's mode)");
else else
PDEBUG_CHAN(DDSP, DEBUG_INFO, "RX Level: %.0f%% Jitter: %.2f Sync Time: %.2f (TS %.2f) %s\n", fabs(level) * 32767.0 / cnetz->fsk_deviation * 100.0, jitter, sync_time, sync_time / 396.0, (level < 0) ? "NEGATIVE (phone's mode)" : "POSITIVE (base station's mode)"); PDEBUG_CHAN(DDSP, DEBUG_INFO, "RX Level: %.0f%% Jitter: %.2f Sync Time: %.2f (TS %.2f) %s\n", fabs(level) / cnetz->fsk_deviation * 100.0, jitter, sync_time, sync_time / 396.0, (level < 0) ? "NEGATIVE (phone's mode)" : "POSITIVE (base station's mode)");
if (cnetz->sender.loopback) { if (cnetz->sender.loopback) {
PDEBUG(DFRAME, DEBUG_NOTICE, "Received Telegramm in loopback test mode (opcode %d = %s)\n", opcode, definition_opcode[opcode].message_name); PDEBUG(DFRAME, DEBUG_NOTICE, "Received Telegramm in loopback test mode (opcode %d = %s)\n", opcode, definition_opcode[opcode].message_name);

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@ -35,6 +35,23 @@
#define DISC_TIMEOUT 30 #define DISC_TIMEOUT 30
//#define DEBUG_LEVEL
#ifdef DEBUG_LEVEL
static double level_of(double *samples, int count)
{
double level = 0;
int i;
for (i = 0; i < count; i++) {
if (samples[i] > level)
level = samples[i];
}
return level;
}
#endif
/* stream patterns/announcements */ /* stream patterns/announcements */
int16_t *test_spl = NULL; int16_t *test_spl = NULL;
int16_t *ringback_spl = NULL; int16_t *ringback_spl = NULL;
@ -221,7 +238,7 @@ static void get_test_patterns(int16_t *samples, int length)
if (pos >= size) if (pos >= size)
*samples++ = 0; *samples++ = 0;
else else
*samples++ = spl[pos] >> 1; *samples++ = spl[pos] >> 2;
if (++pos == max) if (++pos == max)
pos = 0; pos = 0;
} }
@ -477,7 +494,8 @@ int call_init(const char *station_id, const char *audiodev, int samplerate, int
return 0; return 0;
/* open sound device for call control */ /* open sound device for call control */
call.sound = sound_open(audiodev, NULL, NULL, 1, 0.0, samplerate, 3700.0, 0.0); /* use +3.17 dBm0 (factor 1.44) for complete range of sound card */
call.sound = sound_open(audiodev, NULL, NULL, 1, 0.0, samplerate, 1.44, 4000.0);
if (!call.sound) { if (!call.sound) {
PDEBUG(DSENDER, DEBUG_ERROR, "No sound device!\n"); PDEBUG(DSENDER, DEBUG_ERROR, "No sound device!\n");
@ -677,7 +695,6 @@ void process_call(int c)
default: default:
jitter_load(&call.dejitter, samples, count); jitter_load(&call.dejitter, samples, count);
} }
samples_to_int16(spl, samples, count);
samples_list[0] = samples; samples_list[0] = samples;
rc = sound_write(call.sound, samples_list, count, NULL, NULL, 1); rc = sound_write(call.sound, samples_list, count, NULL, NULL, 1);
if (rc < 0) { if (rc < 0) {
@ -904,8 +921,6 @@ void call_in_release(int callref, int cause)
/* forward audio to MNCC or call instance */ /* forward audio to MNCC or call instance */
void call_tx_audio(int callref, sample_t *samples, int count) void call_tx_audio(int callref, sample_t *samples, int count)
{ {
int16_t spl[count];
if (!callref) if (!callref)
return; return;
@ -920,6 +935,10 @@ void call_tx_audio(int callref, sample_t *samples, int count)
/* forward audio */ /* forward audio */
data->msg_type = ANALOG_8000HZ; data->msg_type = ANALOG_8000HZ;
data->callref = callref; data->callref = callref;
#ifdef DEBUG_LEVEL
double lev = level_of(samples, count);
printf(" mobil-level: %s%.4f\n", debug_db(lev), (20 * log10(lev)));
#endif
samples_to_int16((int16_t *)data->data, samples, count); samples_to_int16((int16_t *)data->data, samples, count);
mncc_write(buf, sizeof(buf)); mncc_write(buf, sizeof(buf));
@ -934,6 +953,7 @@ void call_tx_audio(int callref, sample_t *samples, int count)
} else } else
/* else, if no sound is used, send test tone to mobile */ /* else, if no sound is used, send test tone to mobile */
if (call.state == CALL_CONNECT) { if (call.state == CALL_CONNECT) {
int16_t spl[count];
get_test_patterns(spl, count); get_test_patterns(spl, count);
int16_to_samples(samples, spl, count); int16_to_samples(samples, spl, count);
call_rx_audio(callref, samples, count); call_rx_audio(callref, samples, count);
@ -953,6 +973,13 @@ void call_mncc_clock(void)
data->callref = process->callref; data->callref = process->callref;
/* try to get patterns, else copy the samples we got */ /* try to get patterns, else copy the samples we got */
get_process_patterns(process, (int16_t *)data->data, 160); get_process_patterns(process, (int16_t *)data->data, 160);
#ifdef DEBUG_LEVEL
sample_t samples[160];
int16_to_samples(samples, (int16_t *)data->data, 160);
double lev = level_of(samples, 160);
printf(" mobil-level: %s%.4f\n", debug_db(lev), (20 * log10(lev)));
samples_to_int16((int16_t *)data->data, samples, 160);
#endif
mncc_write(buf, sizeof(buf)); mncc_write(buf, sizeof(buf));
} }
process = process->next; process = process->next;
@ -978,6 +1005,10 @@ void call_mncc_recv(uint8_t *buf, int length)
if (is_process_pattern(data->callref)) if (is_process_pattern(data->callref))
return; return;
int16_to_samples(samples, (int16_t *)data->data, count); int16_to_samples(samples, (int16_t *)data->data, count);
#ifdef DEBUG_LEVEL
double lev = level_of(samples, count);
printf("festnetz-level: %s %.4f\n", debug_db(lev), (20 * log10(lev)));
#endif
call_rx_audio(data->callref, samples, count); call_rx_audio(data->callref, samples, count);
return; return;
} }

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@ -35,6 +35,9 @@
/* Minimum level value to keep state */ /* Minimum level value to keep state */
#define ENVELOPE_MIN 0.001 #define ENVELOPE_MIN 0.001
/* Maximum level, to prevent sqrt_tab to overflow */
#define ENVELOPE_MAX 9.990
static double sqrt_tab[10000]; static double sqrt_tab[10000];
/* /*
@ -43,7 +46,7 @@ static double sqrt_tab[10000];
* Hopefully this is correct * Hopefully this is correct
* *
*/ */
void init_compandor(compandor_t *state, int samplerate, double attack_ms, double recovery_ms, int unaffected_level) void init_compandor(compandor_t *state, int samplerate, double attack_ms, double recovery_ms, double unaffected_level)
{ {
int i; int i;
@ -95,6 +98,8 @@ void compress_audio(compandor_t *state, sample_t *samples, int num)
envelope = peak; envelope = peak;
if (envelope < ENVELOPE_MIN) if (envelope < ENVELOPE_MIN)
envelope = ENVELOPE_MIN; envelope = ENVELOPE_MIN;
if (envelope > ENVELOPE_MAX)
envelope = ENVELOPE_MAX;
value = value / sqrt_tab[(int)(envelope / 0.001)]; value = value / sqrt_tab[(int)(envelope / 0.001)];
//if (i > 47000.0 && i < 48144) //if (i > 47000.0 && i < 48144)

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@ -15,7 +15,7 @@ typedef struct compandor {
} e; } e;
} compandor_t; } compandor_t;
void init_compandor(compandor_t *state, int samplerate, double attack_ms, double recovery_ms, int unaffected_level); void init_compandor(compandor_t *state, int samplerate, double attack_ms, double recovery_ms, double unaffected_level);
void compress_audio(compandor_t *state, sample_t *samples, int num); void compress_audio(compandor_t *state, sample_t *samples, int num);
void expand_audio(compandor_t *state, sample_t *samples, int num); void expand_audio(compandor_t *state, sample_t *samples, int num);

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@ -23,7 +23,7 @@ void get_win_size(int *w, int *h);
void display_wave_init(sender_t *sender, int samplerate); void display_wave_init(sender_t *sender, int samplerate);
void display_wave_on(int on); void display_wave_on(int on);
void display_wave_limit_scroll(int on); void display_wave_limit_scroll(int on);
void display_wave(sender_t *sender, sample_t *samples, int length); void display_wave(sender_t *sender, sample_t *samples, int length, double range);
void display_iq_init(int samplerate); void display_iq_init(int samplerate);
void display_iq_on(int on); void display_iq_on(int on);

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@ -20,6 +20,7 @@
#include <stdio.h> #include <stdio.h>
#include <stdint.h> #include <stdint.h>
#include <string.h> #include <string.h>
#include <math.h>
#include <sys/ioctl.h> #include <sys/ioctl.h>
#include "sample.h" #include "sample.h"
#include "sender.h" #include "sender.h"
@ -110,10 +111,10 @@ void display_wave_limit_scroll(int on)
* HEIGHT is odd, so the center line's char is '-' (otherwise '_') * HEIGHT is odd, so the center line's char is '-' (otherwise '_')
* (HEIGHT - 1) / 2 = 1, so the center line is drawn in line 1 * (HEIGHT - 1) / 2 = 1, so the center line is drawn in line 1
* *
* y is in range of 0..5, so these are 5 steps, where 2 to 2.999 is the * y is in range of 0..4, so these are 5 steps, where 2 is the
* center line. this is calculated by (HEIGHT * 2 - 1) * center line. this is calculated by (HEIGHT * 2 - 1)
*/ */
void display_wave(sender_t *sender, sample_t *samples, int length) void display_wave(sender_t *sender, sample_t *samples, int length, double range)
{ {
dispwav_t *disp = &sender->dispwav; dispwav_t *disp = &sender->dispwav;
int pos, max; int pos, max;
@ -147,9 +148,16 @@ void display_wave(sender_t *sender, sample_t *samples, int length)
if (pos == width) { if (pos == width) {
memset(&screen, ' ', sizeof(screen)); memset(&screen, ' ', sizeof(screen));
for (j = 0; j < width; j++) { for (j = 0; j < width; j++) {
y = (32767 - (int32_t)buffer[j]) * (HEIGHT * 2 - 1) / 65536; /* Input value is scaled to range -1 .. 1 and then substracted from 1,
* so the result ranges from 0 .. 2.
* HEIGHT-1 is multiplied with the range, so a HEIGHT of 3 would allow
* 0..4 (5 steps) and a HEIGHT of 11 would allow 0..20 (21 steps).
* We always use odd number of steps, so there will be a center between
* values.
*/
y = round((1.0 - buffer[j] / range) * (double)(HEIGHT - 1));
/* only display level, if it is in range */ /* only display level, if it is in range */
if (y >= 0 && y < HEIGHT * 2) if (y >= 0 && y < HEIGHT * 2 - 1)
screen[y >> 1][j] = (y & 1) ? '_' : '-'; screen[y >> 1][j] = (y & 1) ? '_' : '-';
} }
sprintf(screen[0], "(chan %d", sender->kanal); sprintf(screen[0], "(chan %d", sender->kanal);

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@ -25,10 +25,12 @@
#define PI M_PI #define PI M_PI
#define TX_PEAK_DTMF 7000 /* single dtmf tone peak (note this is half to total peak) */ static double tx_peak_dtmf_low = 0.2818 / SPEECH_LEVEL; /* -11 dBm, relative to speech level */
#define DTMF_DURATION 0.100 /* duration in seconds */ static double tx_peak_dtmf_high = 0.3548 / SPEECH_LEVEL;/* -9 dBm, relative to speech level */
#define DTMF_DURATION 0.100 /* duration in seconds */
static double dsp_sine_dtmf[256]; static sample_t dsp_sine_dtmf_low[65536];
static sample_t dsp_sine_dtmf_high[65536];
void dtmf_init(dtmf_t *dtmf, int samplerate) void dtmf_init(dtmf_t *dtmf, int samplerate)
{ {
@ -39,8 +41,10 @@ void dtmf_init(dtmf_t *dtmf, int samplerate)
dtmf->max = (int)((double)samplerate * DTMF_DURATION + 0.5); dtmf->max = (int)((double)samplerate * DTMF_DURATION + 0.5);
// FIXME: do this globally and not per instance */ // FIXME: do this globally and not per instance */
for (i = 0; i < 256; i++) for (i = 0; i < 65536; i++) {
dsp_sine_dtmf[i] = (int)(sin((double)i / 256.0 * 2.0 * PI) * TX_PEAK_DTMF); dsp_sine_dtmf_low[i] = sin((double)i / 65536.0 * 2.0 * PI) * tx_peak_dtmf_low;
dsp_sine_dtmf_high[i] = sin((double)i / 65536.0 * 2.0 * PI) * tx_peak_dtmf_high;
}
} }
/* set dtmf tone */ /* set dtmf tone */
@ -71,8 +75,8 @@ void dtmf_set_tone(dtmf_t *dtmf, char tone)
} }
dtmf->tone = tone; dtmf->tone = tone;
dtmf->pos = 0; dtmf->pos = 0;
dtmf->phaseshift256[0] = 256.0 / ((double)dtmf->samplerate / f1); dtmf->phaseshift65536[0] = 65536.0 / ((double)dtmf->samplerate / f1);
dtmf->phaseshift256[1] = 256.0 / ((double)dtmf->samplerate / f2); dtmf->phaseshift65536[1] = 65536.0 / ((double)dtmf->samplerate / f2);
} }
/* Generate audio stream from DTMF tone. Keep phase for next call of function. */ /* Generate audio stream from DTMF tone. Keep phase for next call of function. */
@ -87,20 +91,20 @@ void dtmf_tone(dtmf_t *dtmf, sample_t *samples, int length)
return; return;
} }
phaseshift = dtmf->phaseshift256; phaseshift = dtmf->phaseshift65536;
phase = dtmf->phase256; phase = dtmf->phase65536;
pos = dtmf->pos; pos = dtmf->pos;
max = dtmf->max; max = dtmf->max;
for (i = 0; i < length; i++) { for (i = 0; i < length; i++) {
*samples++ = dsp_sine_dtmf[((uint8_t)phase[0]) & 0xff] *samples++ = dsp_sine_dtmf_low[(uint16_t)phase[0]]
+ dsp_sine_dtmf[((uint8_t)phase[1]) & 0xff]; + dsp_sine_dtmf_high[(uint16_t)phase[1]];
phase[0] += phaseshift[0]; phase[0] += phaseshift[0];
if (phase[0] >= 256) if (phase[0] >= 65536)
phase[0] -= 256; phase[0] -= 65536;
phase[1] += phaseshift[1]; phase[1] += phaseshift[1];
if (phase[1] >= 256) if (phase[1] >= 65536)
phase[1] -= 256; phase[1] -= 65536;
/* tone ends */ /* tone ends */
if (++pos == max) { if (++pos == max) {

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@ -4,8 +4,8 @@ typedef struct dtmf {
char tone; /* current tone to be played */ char tone; /* current tone to be played */
int pos; /* sample counter for tone */ int pos; /* sample counter for tone */
int max; /* max number of samples for tone duration */ int max; /* max number of samples for tone duration */
double phaseshift256[2]; /* how much the phase of sine wave changes per sample */ double phaseshift65536[2]; /* how much the phase of sine wave changes per sample */
double phase256[2]; /* current phase */ double phase65536[2]; /* current phase */
} dtmf_t; } dtmf_t;
void dtmf_init(dtmf_t *dtmf, int samplerate); void dtmf_init(dtmf_t *dtmf, int samplerate);

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@ -21,6 +21,7 @@
#include <stdint.h> #include <stdint.h>
#include <string.h> #include <string.h>
#include <math.h> #include <math.h>
#include "sample.h"
#include "filter.h" #include "filter.h"
#include "emphasis.h" #include "emphasis.h"
#include "debug.h" #include "debug.h"
@ -29,7 +30,7 @@
#define CUT_OFF_H 100.0 /* cut-off frequency for high-pass filter */ #define CUT_OFF_H 100.0 /* cut-off frequency for high-pass filter */
static void gen_sine(double *samples, int num, int samplerate, double freq) static void gen_sine(sample_t *samples, int num, int samplerate, double freq)
{ {
int i; int i;
@ -37,7 +38,7 @@ static void gen_sine(double *samples, int num, int samplerate, double freq)
samples[i] = cos(2.0 * M_PI * freq / (double)samplerate * (double)i); samples[i] = cos(2.0 * M_PI * freq / (double)samplerate * (double)i);
} }
static double get_level(double *samples, int num) static double get_level(sample_t *samples, int num)
{ {
int i; int i;
double envelope = 0; double envelope = 0;
@ -52,7 +53,7 @@ static double get_level(double *samples, int num)
int init_emphasis(emphasis_t *state, int samplerate, double cut_off) int init_emphasis(emphasis_t *state, int samplerate, double cut_off)
{ {
double factor; double factor;
double test_samples[samplerate / 10]; sample_t test_samples[samplerate / 10];
memset(state, 0, sizeof(*state)); memset(state, 0, sizeof(*state));
@ -78,7 +79,7 @@ int init_emphasis(emphasis_t *state, int samplerate, double cut_off)
return 0; return 0;
} }
void pre_emphasis(emphasis_t *state, double *samples, int num) void pre_emphasis(emphasis_t *state, sample_t *samples, int num)
{ {
double x, y, x_last, factor, amp; double x, y, x_last, factor, amp;
int i; int i;
@ -101,7 +102,7 @@ void pre_emphasis(emphasis_t *state, double *samples, int num)
state->p.x_last = x_last; state->p.x_last = x_last;
} }
void de_emphasis(emphasis_t *state, double *samples, int num) void de_emphasis(emphasis_t *state, sample_t *samples, int num)
{ {
double x, y, y_last, factor, amp; double x, y, y_last, factor, amp;
int i; int i;
@ -125,7 +126,7 @@ void de_emphasis(emphasis_t *state, double *samples, int num)
} }
/* high pass filter to remove DC and low frequencies */ /* high pass filter to remove DC and low frequencies */
void dc_filter(emphasis_t *state, double *samples, int num) void dc_filter(emphasis_t *state, sample_t *samples, int num)
{ {
filter_process(&state->d.hp, samples, num); filter_process(&state->d.hp, samples, num);
} }

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@ -15,7 +15,7 @@ typedef struct emphasis {
#define CUT_OFF_EMPHASIS_DEFAULT 300.0 #define CUT_OFF_EMPHASIS_DEFAULT 300.0
int init_emphasis(emphasis_t *state, int samplerate, double cut_off); int init_emphasis(emphasis_t *state, int samplerate, double cut_off);
void pre_emphasis(emphasis_t *state, double *samples, int num); void pre_emphasis(emphasis_t *state, sample_t *samples, int num);
void de_emphasis(emphasis_t *state, double *samples, int num); void de_emphasis(emphasis_t *state, sample_t *samples, int num);
void dc_filter(emphasis_t *state, double *samples, int num); void dc_filter(emphasis_t *state, sample_t *samples, int num);

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@ -22,6 +22,7 @@
#include <string.h> #include <string.h>
#include <stdlib.h> #include <stdlib.h>
#include <math.h> #include <math.h>
#include "sample.h"
#include "filter.h" #include "filter.h"
#define PI M_PI #define PI M_PI
@ -65,7 +66,7 @@ void filter_highpass_init(filter_t *bq, double frequency, int samplerate, int it
bq->b2 = (1 - K / Q + K * K) * norm; bq->b2 = (1 - K / Q + K * K) * norm;
} }
void filter_process(filter_t *bq, double *samples, int length) void filter_process(filter_t *bq, sample_t *samples, int length)
{ {
double a0, a1, a2, b1, b2; double a0, a1, a2, b1, b2;
double *z1, *z2; double *z1, *z2;

View File

@ -9,6 +9,6 @@ typedef struct filter {
void filter_lowpass_init(filter_t *bq, double frequency, int samplerate, int iterations); void filter_lowpass_init(filter_t *bq, double frequency, int samplerate, int iterations);
void filter_highpass_init(filter_t *bq, double frequency, int samplerate, int iterations); void filter_highpass_init(filter_t *bq, double frequency, int samplerate, int iterations);
void filter_process(filter_t *bq, double *samples, int length); void filter_process(filter_t *bq, sample_t *samples, int length);
#endif /* _FILTER_H */ #endif /* _FILTER_H */

View File

@ -1,27 +1,64 @@
/* Sample definition
*
* (C) 2017 by Andreas Eversberg <jolly@eversberg.eu>
* All Rights Reserved
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdint.h> #include <stdint.h>
#include "sample.h" #include "sample.h"
/*
* A regular voice conversation takes place at this factor below the full range
* of 16 bits signed value:
*/
static double int_16_speech_level = SPEECH_LEVEL * 0.7079; /* 16 dBm below dBm0, which is about 3dBm below full 16 bit range */
/* A sample_t is a value that has virtually infinite precision but will also
* support high numbers. 'double' or 'float' types are sufficient.
*
* When using sample_t inside signal processing of each base station, the
* level of +- 1 is relative to the normal speach evenlope.
*
* When converting sample_t to int16_t, the level of +- 1 is reduced by factor.
* This way the speech may be louder before clipping happens.
*
* When using sample_t to modulate (SDR or sound card), the level is changed,
* so it represents the frequency deviation in Hz. The deviation of speech
* envelope is network dependant.
*/
void samples_to_int16(int16_t *spl, sample_t *samples, int length) void samples_to_int16(int16_t *spl, sample_t *samples, int length)
{ {
int32_t value;
while (length--) { while (length--) {
if (*samples > 32767.0) value = *samples++ * int_16_speech_level * 32768.0;
*spl = 32767; if (value > 32767.0)
else if (*samples < -32767.0) *spl++ = 32767;
*spl = -32767; else if (value < -32767.0)
*spl++ = -32767;
else else
*spl = (uint16_t)(*samples); *spl++ = (uint16_t)value;
samples++;
spl++;
} }
} }
void int16_to_samples(sample_t *samples, int16_t *spl, int length) void int16_to_samples(sample_t *samples, int16_t *spl, int length)
{ {
while (length--) { while (length--) {
*samples = (double)(*spl); *samples++ = (double)(*spl++) / 32767.0 / int_16_speech_level;
samples++;
spl++;
} }
} }

View File

@ -1,6 +1,8 @@
typedef double sample_t; typedef double sample_t;
#define SPEECH_LEVEL 0.1585
void samples_to_int16(int16_t *spl, sample_t *samples, int length); void samples_to_int16(int16_t *spl, sample_t *samples, int length);
void int16_to_samples(sample_t *samples, int16_t *spl, int length); void int16_to_samples(sample_t *samples, int16_t *spl, int length);

View File

@ -124,7 +124,7 @@ int samplerate_upsample(samplerate_t *state, sample_t *input, int input_num, sam
if (input == output) { if (input == output) {
/* copy samples */ /* copy samples */
for (i = 0; i < input_num; i++) for (i = 0; i < output_num; i++)
*output++ = samples[i]; *output++ = samples[i];
} }

View File

@ -47,7 +47,6 @@ typedef struct sdr {
sdr_chan_t *chan; /* settings for all channels */ sdr_chan_t *chan; /* settings for all channels */
int paging_channel; /* if set, points to paging channel */ int paging_channel; /* if set, points to paging channel */
sdr_chan_t paging_chan; /* settings for extra paging channel */ sdr_chan_t paging_chan; /* settings for extra paging channel */
double spl_deviation; /* how to convert a sample step into deviation (Hz) */
int channels; /* number of frequencies */ int channels; /* number of frequencies */
double samplerate; /* IQ rate */ double samplerate; /* IQ rate */
double amplitude; /* amplitude of each carrier */ double amplitude; /* amplitude of each carrier */
@ -84,15 +83,19 @@ int sdr_init(const char *device_args, double rx_gain, double tx_gain, const char
return 0; return 0;
} }
void *sdr_open(const char __attribute__((__unused__)) *audiodev, double *tx_frequency, double *rx_frequency, int channels, double paging_frequency, int samplerate, double bandwidth, double sample_deviation) void *sdr_open(const char __attribute__((__unused__)) *audiodev, double *tx_frequency, double *rx_frequency, int channels, double paging_frequency, int samplerate, double max_deviation, double max_modulation)
{ {
sdr_t *sdr; sdr_t *sdr;
double bandwidth;
double tx_center_frequency, rx_center_frequency; double tx_center_frequency, rx_center_frequency;
int rc; int rc;
int c; int c;
display_iq_init(samplerate); display_iq_init(samplerate);
bandwidth = 2.0 * (max_deviation + max_modulation);
PDEBUG(DSDR, DEBUG_INFO, "Using Bandwidth of 2 * (%.1f + %.1f) = %.1f\n", max_deviation / 1000, max_modulation / 1000, bandwidth / 1000);
if (channels < 1) { if (channels < 1) {
PDEBUG(DSDR, DEBUG_ERROR, "No channel given, please fix!\n"); PDEBUG(DSDR, DEBUG_ERROR, "No channel given, please fix!\n");
abort(); abort();
@ -105,7 +108,6 @@ void *sdr_open(const char __attribute__((__unused__)) *audiodev, double *tx_freq
} }
sdr->channels = channels; sdr->channels = channels;
sdr->samplerate = samplerate; sdr->samplerate = samplerate;
sdr->spl_deviation = sample_deviation;
sdr->amplitude = 0.4 / (double)channels; // FIXME: actual amplitude 0.1? sdr->amplitude = 0.4 / (double)channels; // FIXME: actual amplitude 0.1?
/* special case where we use a paging frequency */ /* special case where we use a paging frequency */
@ -124,8 +126,8 @@ void *sdr_open(const char __attribute__((__unused__)) *audiodev, double *tx_freq
PDEBUG(DSDR, DEBUG_INFO, "Frequency #%d: TX = %.6f MHz, RX = %.6f MHz\n", c, tx_frequency[c] / 1e6, rx_frequency[c] / 1e6); PDEBUG(DSDR, DEBUG_INFO, "Frequency #%d: TX = %.6f MHz, RX = %.6f MHz\n", c, tx_frequency[c] / 1e6, rx_frequency[c] / 1e6);
sdr->chan[c].tx_frequency = tx_frequency[c]; sdr->chan[c].tx_frequency = tx_frequency[c];
sdr->chan[c].rx_frequency = rx_frequency[c]; sdr->chan[c].rx_frequency = rx_frequency[c];
filter_lowpass_init(&sdr->chan[c].rx_lp[0], bandwidth, samplerate, 1); filter_lowpass_init(&sdr->chan[c].rx_lp[0], bandwidth / 2.0, samplerate, 1);
filter_lowpass_init(&sdr->chan[c].rx_lp[1], bandwidth, samplerate, 1); filter_lowpass_init(&sdr->chan[c].rx_lp[1], bandwidth / 2.0, samplerate, 1);
} }
if (sdr->paging_channel) { if (sdr->paging_channel) {
PDEBUG(DSDR, DEBUG_INFO, "Paging Frequency: TX = %.6f MHz\n", paging_frequency / 1e6); PDEBUG(DSDR, DEBUG_INFO, "Paging Frequency: TX = %.6f MHz\n", paging_frequency / 1e6);
@ -190,21 +192,21 @@ void *sdr_open(const char __attribute__((__unused__)) *audiodev, double *tx_freq
PDEBUG(DSDR, DEBUG_INFO, "Using gain: TX %.1f dB, RX %.1f dB\n", sdr_tx_gain, sdr_rx_gain); PDEBUG(DSDR, DEBUG_INFO, "Using gain: TX %.1f dB, RX %.1f dB\n", sdr_tx_gain, sdr_rx_gain);
if (sdr_write_iq_rx_wave) { if (sdr_write_iq_rx_wave) {
rc = wave_create_record(&sdr->wave_rx_rec, sdr_write_iq_rx_wave, sdr->samplerate, 2); rc = wave_create_record(&sdr->wave_rx_rec, sdr_write_iq_rx_wave, sdr->samplerate, 2, 1.0);
if (rc < 0) { if (rc < 0) {
PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE recoding instance!\n"); PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE recoding instance!\n");
goto error; goto error;
} }
} }
if (sdr_write_iq_tx_wave) { if (sdr_write_iq_tx_wave) {
rc = wave_create_record(&sdr->wave_tx_rec, sdr_write_iq_tx_wave, sdr->samplerate, 2); rc = wave_create_record(&sdr->wave_tx_rec, sdr_write_iq_tx_wave, sdr->samplerate, 2, 1.0);
if (rc < 0) { if (rc < 0) {
PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE recoding instance!\n"); PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE recoding instance!\n");
goto error; goto error;
} }
} }
if (sdr_read_iq_rx_wave) { if (sdr_read_iq_rx_wave) {
rc = wave_create_playback(&sdr->wave_rx_play, sdr_read_iq_rx_wave, sdr->samplerate, 2); rc = wave_create_playback(&sdr->wave_rx_play, sdr_read_iq_rx_wave, sdr->samplerate, 2, 1.0);
if (rc < 0) { if (rc < 0) {
PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE playback instance!\n"); PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE playback instance!\n");
goto error; goto error;
@ -269,7 +271,7 @@ int sdr_write(void *inst, sample_t **samples, int num, enum paging_signal __attr
/* modulate */ /* modulate */
for (s = 0, ss = 0; s < num; s++) { for (s = 0, ss = 0; s < num; s++) {
/* deviation is defined by the sample value and the offset */ /* deviation is defined by the sample value and the offset */
dev = offset + (double)samples[c][s] * sdr->spl_deviation; dev = offset + samples[c][s];
#ifdef FAST_SINE #ifdef FAST_SINE
phase += 256.0 * dev / rate; phase += 256.0 * dev / rate;
if (phase < 0.0) if (phase < 0.0)
@ -294,20 +296,8 @@ int sdr_write(void *inst, sample_t **samples, int num, enum paging_signal __attr
if (sdr->wave_tx_rec.fp) { if (sdr->wave_tx_rec.fp) {
sample_t spl[2][num], *spl_list[2] = { spl[0], spl[1] }; sample_t spl[2][num], *spl_list[2] = { spl[0], spl[1] };
for (s = 0, ss = 0; s < num; s++) { for (s = 0, ss = 0; s < num; s++) {
if (buff[ss] >= 1.0) spl[0][s] = buff[ss++];
spl[0][s] = 32767.0; spl[1][s] = buff[ss++];
else if (buff[ss] <= -1.0)
spl[0][s] = -32767.0;
else
spl[0][s] = 32767.0 * buff[ss];
ss++;
if (buff[ss] >= 1.0)
spl[1][s] = 32767.0;
else if (buff[ss] <= -1.0)
spl[1][s] = -32767.0;
else
spl[1][s] = 32767.0 * buff[ss];
ss++;
} }
wave_write(&sdr->wave_tx_rec, spl_list, num); wave_write(&sdr->wave_tx_rec, spl_list, num);
} }
@ -325,7 +315,7 @@ int sdr_read(void *inst, sample_t **samples, int num, int channels)
{ {
sdr_t *sdr = (sdr_t *)inst; sdr_t *sdr = (sdr_t *)inst;
float buff[num * 2]; float buff[num * 2];
double I[num], Q[num], i, q; sample_t I[num], Q[num], i, q;
int count; int count;
int c, s, ss; int c, s, ss;
double phase, rot, last_phase, dev, rate; double phase, rot, last_phase, dev, rate;
@ -341,20 +331,8 @@ int sdr_read(void *inst, sample_t **samples, int num, int channels)
if (sdr->wave_rx_rec.fp) { if (sdr->wave_rx_rec.fp) {
sample_t spl[2][count], *spl_list[2] = { spl[0], spl[1] }; sample_t spl[2][count], *spl_list[2] = { spl[0], spl[1] };
for (s = 0, ss = 0; s < count; s++) { for (s = 0, ss = 0; s < count; s++) {
if (buff[ss] >= 1.0) spl[0][s] = buff[ss++];
spl[0][s] = 32767.0; spl[1][s] = buff[ss++];
else if (buff[ss] <= -1.0)
spl[0][s] = -32767.0;
else
spl[0][s] = 32767.0 * buff[ss];
ss++;
if (buff[ss] >= 1.0)
spl[1][s] = 32767.0;
else if (buff[ss] <= -1.0)
spl[1][s] = -32767.0;
else
spl[1][s] = 32767.0 * buff[ss];
ss++;
} }
wave_write(&sdr->wave_rx_rec, spl_list, count); wave_write(&sdr->wave_rx_rec, spl_list, count);
} }
@ -362,8 +340,8 @@ int sdr_read(void *inst, sample_t **samples, int num, int channels)
sample_t spl[2][count], *spl_list[2] = { spl[0], spl[1] }; sample_t spl[2][count], *spl_list[2] = { spl[0], spl[1] };
wave_read(&sdr->wave_rx_play, spl_list, count); wave_read(&sdr->wave_rx_play, spl_list, count);
for (s = 0, ss = 0; s < count; s++) { for (s = 0, ss = 0; s < count; s++) {
buff[ss++] = spl[0][s] / 32767.0; buff[ss++] = spl[0][s];
buff[ss++] = spl[1][s] / 32767.0; buff[ss++] = spl[1][s];
} }
} }
display_iq(buff, count); display_iq(buff, count);
@ -391,7 +369,7 @@ int sdr_read(void *inst, sample_t **samples, int num, int channels)
else if (dev > 0.49) else if (dev > 0.49)
dev -= 1.0; dev -= 1.0;
dev *= rate; dev *= rate;
samples[c][s] = dev / sdr->spl_deviation; samples[c][s] = dev;
} }
sdr->chan[c].rx_last_phase = last_phase; sdr->chan[c].rx_last_phase = last_phase;
} }

View File

@ -41,8 +41,6 @@ int sender_create(sender_t *sender, int kanal, double sendefrequenz, double empf
sender->kanal = kanal; sender->kanal = kanal;
sender->sendefrequenz = sendefrequenz; sender->sendefrequenz = sendefrequenz;
sender->empfangsfrequenz = empfangsfrequenz; sender->empfangsfrequenz = empfangsfrequenz;
sender->bandwidth = 4000; /* default is overwritten by dsp.c */
sender->sample_deviation = 0.2; /* default is overwritten by dsp.c */
strncpy(sender->audiodev, audiodev, sizeof(sender->audiodev) - 1); strncpy(sender->audiodev, audiodev, sizeof(sender->audiodev) - 1);
sender->samplerate = samplerate; sender->samplerate = samplerate;
sender->rx_gain = rx_gain; sender->rx_gain = rx_gain;
@ -168,21 +166,21 @@ int sender_open_audio(void)
} }
if (master->write_rx_wave) { if (master->write_rx_wave) {
rc = wave_create_record(&master->wave_rx_rec, master->write_rx_wave, master->samplerate, channels); rc = wave_create_record(&master->wave_rx_rec, master->write_rx_wave, master->samplerate, channels, master->max_deviation);
if (rc < 0) { if (rc < 0) {
PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE recoding instance!\n"); PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE recoding instance!\n");
return rc; return rc;
} }
} }
if (master->write_tx_wave) { if (master->write_tx_wave) {
rc = wave_create_record(&master->wave_tx_rec, master->write_tx_wave, master->samplerate, channels); rc = wave_create_record(&master->wave_tx_rec, master->write_tx_wave, master->samplerate, channels, master->max_deviation);
if (rc < 0) { if (rc < 0) {
PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE recoding instance!\n"); PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE recoding instance!\n");
return rc; return rc;
} }
} }
if (master->read_rx_wave) { if (master->read_rx_wave) {
rc = wave_create_playback(&master->wave_rx_play, master->read_rx_wave, master->samplerate, channels); rc = wave_create_playback(&master->wave_rx_play, master->read_rx_wave, master->samplerate, channels, master->max_deviation);
if (rc < 0) { if (rc < 0) {
PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE playback instance!\n"); PDEBUG(DSENDER, DEBUG_ERROR, "Failed to create WAVE playback instance!\n");
return rc; return rc;
@ -190,7 +188,7 @@ int sender_open_audio(void)
} }
/* open device */ /* open device */
master->audio = master->audio_open(master->audiodev, tx_f, rx_f, channels, paging_frequency, master->samplerate, master->bandwidth, master->sample_deviation); master->audio = master->audio_open(master->audiodev, tx_f, rx_f, channels, paging_frequency, master->samplerate, master->max_deviation, master->max_modulation);
if (!master->audio) { if (!master->audio) {
PDEBUG(DSENDER, DEBUG_ERROR, "No audio device!\n"); PDEBUG(DSENDER, DEBUG_ERROR, "No audio device!\n");
return -EIO; return -EIO;
@ -225,6 +223,17 @@ void sender_destroy(sender_t *sender)
jitter_destroy(&sender->dejitter); jitter_destroy(&sender->dejitter);
} }
void sender_set_fm(sender_t *sender, double max_deviation, double max_modulation, double dBm0_deviation, double max_display)
{
sender->max_deviation = max_deviation;
sender->max_modulation = max_modulation;
sender->dBm0_deviation = dBm0_deviation;
sender->max_display = max_display;
PDEBUG_CHAN(DSENDER, DEBUG_DEBUG, "Maxium deviation: %.1f kHz, Maximum modulation: %.1f kHz\n", max_deviation / 1000.0, max_modulation / 1000.0);
PDEBUG_CHAN(DSENDER, DEBUG_DEBUG, "Deviation at dBm0 (audio level): %.1f kHz\n", dBm0_deviation / 1000.0);
}
static void gain_samples(sample_t *samples, int length, double gain) static void gain_samples(sample_t *samples, int length, double gain)
{ {
int i; int i;
@ -278,12 +287,14 @@ cant_recover:
sender_send(inst, samples[i], count); sender_send(inst, samples[i], count);
/* internal loopback: loop back TX audio to RX */ /* internal loopback: loop back TX audio to RX */
if (inst->loopback == 1) { if (inst->loopback == 1) {
display_wave(inst, samples[i], count); display_wave(inst, samples[i], count, inst->max_display);
sender_receive(inst, samples[i], count); sender_receive(inst, samples[i], count);
} }
/* do pre emphasis towards radio */ /* do pre emphasis towards radio */
if (inst->pre_emphasis) if (inst->pre_emphasis)
pre_emphasis(&inst->estate, samples[i], count); pre_emphasis(&inst->estate, samples[i], count);
/* normal level to frequency deviation of dBm0 */
gain_samples(samples[i], count, inst->dBm0_deviation);
/* set paging signal */ /* set paging signal */
paging_signal[i] = inst->paging_signal; paging_signal[i] = inst->paging_signal;
on[i] = inst->paging_on; on[i] = inst->paging_on;
@ -328,6 +339,8 @@ transmit_later:
/* loop through all channels */ /* loop through all channels */
for (i = 0, inst = sender; inst; i++, inst = inst->slave) { for (i = 0, inst = sender; inst; i++, inst = inst->slave) {
/* frequency deviation of dBm0 to normal level */
gain_samples(samples[i], count, 1.0 / inst->dBm0_deviation);
/* rx gain */ /* rx gain */
if (inst->rx_gain != 1.0) if (inst->rx_gain != 1.0)
gain_samples(samples[i], count, inst->rx_gain); gain_samples(samples[i], count, inst->rx_gain);
@ -337,7 +350,7 @@ transmit_later:
de_emphasis(&inst->estate, samples[i], count); de_emphasis(&inst->estate, samples[i], count);
} }
if (inst->loopback != 1) { if (inst->loopback != 1) {
display_wave(inst, samples[i], count); display_wave(inst, samples[i], count, inst->max_display);
sender_receive(inst, samples[i], count); sender_receive(inst, samples[i], count);
} }
if (inst->loopback == 3) if (inst->loopback == 3)

View File

@ -31,8 +31,12 @@ typedef struct sender {
double sendefrequenz; /* transmitter frequency */ double sendefrequenz; /* transmitter frequency */
double empfangsfrequenz; /* receiver frequency */ double empfangsfrequenz; /* receiver frequency */
double ruffrequenz; /* special paging frequency used for B-Netz */ double ruffrequenz; /* special paging frequency used for B-Netz */
double bandwidth; /* max NF frequency to be transmitted unaffected by filtering */
double sample_deviation; /* frequency deviation of one sample step (after pre-emphasis) */ /* fm levels */
double max_deviation; /* max frequency deviation */
double max_modulation; /* max frequency modulated */
double dBm0_deviation; /* deviation of 1000 Hz reference tone at dBm0 */
double max_display; /* level of displaying wave form */
/* audio */ /* audio */
void *audio; void *audio;
@ -85,6 +89,7 @@ extern int cant_recover;
int sender_create(sender_t *sender, int kanal, double sendefrequenz, double empfangsfrequenz, const char *audiodev, int samplerate, double rx_gain, int pre_emphasis, int de_emphasis, const char *write_rx_wave, const char *write_tx_wave, const char *read_rx_wave, int loopback, double loss_volume, enum paging_signal paging_signal); int sender_create(sender_t *sender, int kanal, double sendefrequenz, double empfangsfrequenz, const char *audiodev, int samplerate, double rx_gain, int pre_emphasis, int de_emphasis, const char *write_rx_wave, const char *write_tx_wave, const char *read_rx_wave, int loopback, double loss_volume, enum paging_signal paging_signal);
void sender_destroy(sender_t *sender); void sender_destroy(sender_t *sender);
void sender_set_fm(sender_t *sender, double max_deviation, double max_modulation, double dBm0_deviation, double max_display);
int sender_open_audio(void); int sender_open_audio(void);
void process_sender_audio(sender_t *sender, int *quit, int latspl); void process_sender_audio(sender_t *sender, int *quit, int latspl);
void sender_send(sender_t *sender, sample_t *samples, int count); void sender_send(sender_t *sender, sample_t *samples, int count);

View File

@ -27,6 +27,7 @@
typedef struct sound { typedef struct sound {
snd_pcm_t *phandle, *chandle; snd_pcm_t *phandle, *chandle;
int pchannels, cchannels; int pchannels, cchannels;
double spl_deviation; /* how much deviation is one sample step */
double paging_phaseshift; /* phase to shift every sample */ double paging_phaseshift; /* phase to shift every sample */
double paging_phase; /* current phase */ double paging_phase; /* current phase */
} sound_t; } sound_t;
@ -131,7 +132,7 @@ static int sound_prepare(sound_t *sound)
return 0; return 0;
} }
void *sound_open(const char *audiodev, double __attribute__((unused)) *tx_frequency, double __attribute__((unused)) *rx_frequency, int channels, double __attribute__((unused)) paging_frequency, int samplerate, double __attribute__((unused)) bandwidth, double __attribute__((unused)) sample_deviation) void *sound_open(const char *audiodev, double __attribute__((unused)) *tx_frequency, double __attribute__((unused)) *rx_frequency, int channels, double __attribute__((unused)) paging_frequency, int samplerate, double max_deviation, double __attribute__((unused)) max_modulation)
{ {
sound_t *sound; sound_t *sound;
int rc; int rc;
@ -147,6 +148,7 @@ void *sound_open(const char *audiodev, double __attribute__((unused)) *tx_freque
return NULL; return NULL;
} }
sound->spl_deviation = max_deviation / 32767.0;
sound->paging_phaseshift = 1.0 / ((double)samplerate / 1000.0); sound->paging_phaseshift = 1.0 / ((double)samplerate / 1000.0);
rc = snd_pcm_open(&sound->phandle, audiodev, SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK); rc = snd_pcm_open(&sound->phandle, audiodev, SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
@ -252,6 +254,7 @@ static void gen_paging_tone(sound_t *sound, int16_t *samples, int length, enum p
int sound_write(void *inst, sample_t **samples, int num, enum paging_signal *paging_signal, int *on, int channels) int sound_write(void *inst, sample_t **samples, int num, enum paging_signal *paging_signal, int *on, int channels)
{ {
sound_t *sound = (sound_t *)inst; sound_t *sound = (sound_t *)inst;
double spl_deviation = sound->spl_deviation;
int32_t value; int32_t value;
int16_t buff[num << 1]; int16_t buff[num << 1];
int rc; int rc;
@ -263,7 +266,7 @@ int sound_write(void *inst, sample_t **samples, int num, enum paging_signal *pag
int16_t paging[num << 1]; int16_t paging[num << 1];
gen_paging_tone(sound, paging, num, paging_signal[0], on[0]); gen_paging_tone(sound, paging, num, paging_signal[0], on[0]);
for (i = 0, ii = 0; i < num; i++) { for (i = 0, ii = 0; i < num; i++) {
value = samples[0][i]; value = samples[0][i] / spl_deviation;
if (value > 32767) if (value > 32767)
value = 32767; value = 32767;
else if (value < -32767) else if (value < -32767)
@ -273,13 +276,13 @@ int sound_write(void *inst, sample_t **samples, int num, enum paging_signal *pag
} }
} else if (channels == 2) { } else if (channels == 2) {
for (i = 0, ii = 0; i < num; i++) { for (i = 0, ii = 0; i < num; i++) {
value = samples[0][i]; value = samples[0][i] / spl_deviation;
if (value > 32767) if (value > 32767)
value = 32767; value = 32767;
else if (value < -32767) else if (value < -32767)
value = -32767; value = -32767;
buff[ii++] = value; buff[ii++] = value;
value = samples[1][i]; value = samples[1][i] / spl_deviation;
if (value > 32767) if (value > 32767)
value = 32767; value = 32767;
else if (value < -32767) else if (value < -32767)
@ -288,7 +291,7 @@ int sound_write(void *inst, sample_t **samples, int num, enum paging_signal *pag
} }
} else { } else {
for (i = 0, ii = 0; i < num; i++) { for (i = 0, ii = 0; i < num; i++) {
value = samples[0][i]; value = samples[0][i] / spl_deviation;
if (value > 32767) if (value > 32767)
value = 32767; value = 32767;
else if (value < -32767) else if (value < -32767)
@ -300,7 +303,7 @@ int sound_write(void *inst, sample_t **samples, int num, enum paging_signal *pag
} else { } else {
/* one channel */ /* one channel */
for (i = 0, ii = 0; i < num; i++) { for (i = 0, ii = 0; i < num; i++) {
value = samples[0][i]; value = samples[0][i] / spl_deviation;
if (value > 32767) if (value > 32767)
value = 32767; value = 32767;
else if (value < -32767) else if (value < -32767)
@ -328,6 +331,7 @@ int sound_write(void *inst, sample_t **samples, int num, enum paging_signal *pag
int sound_read(void *inst, sample_t **samples, int num, int channels) int sound_read(void *inst, sample_t **samples, int num, int channels)
{ {
sound_t *sound = (sound_t *)inst; sound_t *sound = (sound_t *)inst;
double spl_deviation = sound->spl_deviation;
int16_t buff[num << 1]; int16_t buff[num << 1];
int32_t spl; int32_t spl;
int in, rc; int in, rc;
@ -361,17 +365,17 @@ int sound_read(void *inst, sample_t **samples, int num, int channels)
for (i = 0, ii = 0; i < rc; i++) { for (i = 0, ii = 0; i < rc; i++) {
spl = buff[ii++]; spl = buff[ii++];
spl += buff[ii++]; spl += buff[ii++];
samples[0][i] = (sample_t)spl; samples[0][i] = (double)spl * spl_deviation;
} }
} else { } else {
for (i = 0, ii = 0; i < rc; i++) { for (i = 0, ii = 0; i < rc; i++) {
samples[0][i] = (sample_t)buff[ii++]; samples[0][i] = (double)buff[ii++] * spl_deviation;
samples[1][i] = (sample_t)buff[ii++]; samples[1][i] = (double)buff[ii++] * spl_deviation;
} }
} }
} else { } else {
for (i = 0, ii = 0; i < rc; i++) { for (i = 0, ii = 0; i < rc; i++) {
samples[0][i] = (sample_t)buff[ii++]; samples[0][i] = (double)buff[ii++] * spl_deviation;
} }
} }

View File

@ -34,7 +34,7 @@ struct fmt {
uint16_t bits_sample; /* bits per sample (one channel) */ uint16_t bits_sample; /* bits per sample (one channel) */
}; };
int wave_create_record(wave_rec_t *rec, const char *filename, int samplerate, int channels) int wave_create_record(wave_rec_t *rec, const char *filename, int samplerate, int channels, double max_deviation)
{ {
/* RIFFxxxxWAVEfmt xxxx(fmt size)dataxxxx... */ /* RIFFxxxxWAVEfmt xxxx(fmt size)dataxxxx... */
char dummyheader[4 + 4 + 4 + 4 + 4 + sizeof(struct fmt) + 4 + 4]; char dummyheader[4 + 4 + 4 + 4 + 4 + sizeof(struct fmt) + 4 + 4];
@ -43,6 +43,7 @@ int wave_create_record(wave_rec_t *rec, const char *filename, int samplerate, in
memset(rec, 0, sizeof(*rec)); memset(rec, 0, sizeof(*rec));
rec->samplerate = samplerate; rec->samplerate = samplerate;
rec->channels = channels; rec->channels = channels;
rec->max_deviation = max_deviation;
rec->fp = fopen(filename, "w"); rec->fp = fopen(filename, "w");
if (!rec->fp) { if (!rec->fp) {
@ -58,7 +59,7 @@ int wave_create_record(wave_rec_t *rec, const char *filename, int samplerate, in
return 0; return 0;
} }
int wave_create_playback(wave_play_t *play, const char *filename, int samplerate, int channels) int wave_create_playback(wave_play_t *play, const char *filename, int samplerate, int channels, double max_deviation)
{ {
uint8_t buffer[256]; uint8_t buffer[256];
struct fmt fmt; struct fmt fmt;
@ -68,6 +69,7 @@ int wave_create_playback(wave_play_t *play, const char *filename, int samplerate
memset(play, 0, sizeof(*play)); memset(play, 0, sizeof(*play));
play->channels = channels; play->channels = channels;
play->max_deviation = max_deviation;
play->fp = fopen(filename, "r"); play->fp = fopen(filename, "r");
if (!play->fp) { if (!play->fp) {
@ -196,6 +198,8 @@ error:
int wave_read(wave_play_t *play, sample_t **samples, int length) int wave_read(wave_play_t *play, sample_t **samples, int length)
{ {
double max_deviation = play->max_deviation;
int16_t value; /* must be int16, so assembling bytes work */
uint8_t buff[2 * length * play->channels]; uint8_t buff[2 * length * play->channels];
int __attribute__((__unused__)) len; int __attribute__((__unused__)) len;
int i, j, c; int i, j, c;
@ -212,11 +216,12 @@ int wave_read(wave_play_t *play, sample_t **samples, int length)
if (!play->left) if (!play->left)
printf("*** Finished reading WAVE file.\n"); printf("*** Finished reading WAVE file.\n");
/* read and correct endiness */ /* read and correct endianness */
len = fread(buff, 1, 2 * length * play->channels, play->fp); len = fread(buff, 1, 2 * length * play->channels, play->fp);
for (i = 0, j = 0; i < length; i++) { for (i = 0, j = 0; i < length; i++) {
for (c = 0; c < play->channels; c++) { for (c = 0; c < play->channels; c++) {
samples[c][i] = (double)(buff[j] + (buff[j + 1] << 8)); value = buff[j] + (buff[j + 1] << 8);
samples[c][i] = (double)value / 32767.0 * max_deviation;
j += 2; j += 2;
} }
} }
@ -226,15 +231,16 @@ int wave_read(wave_play_t *play, sample_t **samples, int length)
int wave_write(wave_rec_t *rec, sample_t **samples, int length) int wave_write(wave_rec_t *rec, sample_t **samples, int length)
{ {
double max_deviation = rec->max_deviation;
int32_t value; int32_t value;
uint8_t buff[2 * length * rec->channels]; uint8_t buff[2 * length * rec->channels];
int __attribute__((__unused__)) len; int __attribute__((__unused__)) len;
int i, j, c; int i, j, c;
/* write and correct endiness */ /* write and correct endianness */
for (i = 0, j = 0; i < length; i++) { for (i = 0, j = 0; i < length; i++) {
for (c = 0; c < rec->channels; c++) { for (c = 0; c < rec->channels; c++) {
value = samples[c][i]; value = samples[c][i] / max_deviation * 32767.0;
if (value > 32767) if (value > 32767)
value = 32767; value = 32767;
else if (value < -32767) else if (value < -32767)

View File

@ -2,6 +2,7 @@
typedef struct wave_rec { typedef struct wave_rec {
FILE *fp; FILE *fp;
int channels; int channels;
double max_deviation;
int samplerate; int samplerate;
uint32_t written; /* how much samples written */ uint32_t written; /* how much samples written */
} wave_rec_t; } wave_rec_t;
@ -9,11 +10,12 @@ typedef struct wave_rec {
typedef struct wave_play { typedef struct wave_play {
FILE *fp; FILE *fp;
int channels; int channels;
double max_deviation;
uint32_t left; /* how much samples left */ uint32_t left; /* how much samples left */
} wave_play_t; } wave_play_t;
int wave_create_record(wave_rec_t *rec, const char *filename, int samplerate, int channels); int wave_create_record(wave_rec_t *rec, const char *filename, int samplerate, int channels, double max_deviation);
int wave_create_playback(wave_play_t *play, const char *filename, int samplerate, int channels); int wave_create_playback(wave_play_t *play, const char *filename, int samplerate, int channels, double max_deviation);
int wave_read(wave_play_t *play, sample_t **samples, int length); int wave_read(wave_play_t *play, sample_t **samples, int length);
int wave_write(wave_rec_t *rec, sample_t **samples, int length); int wave_write(wave_rec_t *rec, sample_t **samples, int length);
void wave_destroy_record(wave_rec_t *rec); void wave_destroy_record(wave_rec_t *rec);

View File

@ -34,23 +34,36 @@
#define PI M_PI #define PI M_PI
/* Notes on frequency deviation of supervidory signal: /* Notes on TX_PEAK_FSK level:
* *
* The FSK deviation at 1500 Hz is 3.5 KHz. If we use a level of 10000 * This deviation is -2.2db below the dBm0 deviation.
* The supervisory deviation shall be 0.3 KHz: 10000 / 3.5 * 0.3 = 857 *
* Supervisory is raised by pre-emphasis by factor 2.68 (4015 / 1500), * At 1800 Hz the deviation shall be 4.2 kHz, so with emphasis the deviation
* so we need to lower it: 857 / 2.68 = 320 * at 1000 Hz would be theoretically 2.333 kHz. This is factor 0.777 below
* 3 kHz deviation we want at dBm0.
*/
/* Notes on TX_PEAK_SUPER (supervisory signal) level:
*
* This level has 0.3 kHz deviation at 4015 Hz.
*
* Same calculation as above, but now we want 0.3 kHz deviation after emphasis,
* so we calculate what we would need at 1000 Hz in relation to 3 kHz
* deviation.
*/ */
/* signaling */ /* signaling */
#define BANDWIDTH 6000.0 /* maximum bandwidth FIXME */ #define MAX_DEVIATION 4700.0
#define COMPANDOR_0DB 32767 /* works quite well */ #define MAX_MODULATION 4055.0
#define TX_PEAK_FSK 10000.0 /* peak amplitude of signaling FSK +-3.5 KHz @ 1500 Hz */ #define DBM0_DEVIATION 3000.0 /* deviation of dBm0 at 1 kHz */
#define TX_PEAK_SUPER (TX_PEAK_FSK / 3.5 * 0.3 / 2.68) /* peak amplitude of supervisory signal +-0.3 KHz @ 4015 Hz */ #define COMPANDOR_0DB 1.0 /* A level of 0dBm (1.0) shall be unaccected */
#define TX_PEAK_FSK (4200.0 / 1800.0 * 1000.0 / DBM0_DEVIATION)
#define TX_PEAK_SUPER (300.0 / 4015.0 * 1000.0 / DBM0_DEVIATION)
#define MAX_DISPLAY 1.4 /* something above dBm0 */
#define BIT_RATE 1200 /* baud rate */ #define BIT_RATE 1200 /* baud rate */
#define STEPS_PER_BIT 10 /* step every 1/12000 sec */ #define FILTER_STEPS 0.1 /* step every 1/12000 sec */
#define DIALTONE_HZ 425.0 /* dial tone frequency */ #define DIALTONE_HZ 425.0 /* dial tone frequency */
#define TX_PEAK_DIALTONE 16000.0 /* dial tone peak */ #define TX_PEAK_DIALTONE 0.5 /* dial tone peak FIXME */
#define SUPER_DURATION 0.25 /* duration of supervisory signal measurement */ #define SUPER_DURATION 0.25 /* duration of supervisory signal measurement */
#define SUPER_DETECT_COUNT 4 /* number of measures to detect supervisory signal */ #define SUPER_DETECT_COUNT 4 /* number of measures to detect supervisory signal */
#define MUTE_DURATION 0.280 /* a tiny bit more than two frames */ #define MUTE_DURATION 0.280 /* a tiny bit more than two frames */
@ -71,9 +84,9 @@ static double super_freq[5] = {
}; };
/* table for fast sine generation */ /* table for fast sine generation */
static double dsp_tone_bit[2][2][256]; /* polarity, bit, phase */ static sample_t dsp_tone_bit[2][2][65536]; /* polarity, bit, phase */
static double dsp_sine_super[256]; static sample_t dsp_sine_super[65536];
static double dsp_sine_dialtone[256]; static sample_t dsp_sine_dialtone[65536];
/* global init for FSK */ /* global init for FSK */
void dsp_init(void) void dsp_init(void)
@ -82,8 +95,8 @@ void dsp_init(void)
double s; double s;
PDEBUG(DDSP, DEBUG_DEBUG, "Generating sine table for supervisory signal.\n"); PDEBUG(DDSP, DEBUG_DEBUG, "Generating sine table for supervisory signal.\n");
for (i = 0; i < 256; i++) { for (i = 0; i < 65536; i++) {
s = sin((double)i / 256.0 * 2.0 * PI); s = sin((double)i / 65536.0 * 2.0 * PI);
/* supervisor sine */ /* supervisor sine */
dsp_sine_super[i] = s * TX_PEAK_SUPER; dsp_sine_super[i] = s * TX_PEAK_SUPER;
/* dialtone sine */ /* dialtone sine */
@ -92,7 +105,7 @@ void dsp_init(void)
dsp_tone_bit[0][1][i] = s * TX_PEAK_FSK; dsp_tone_bit[0][1][i] = s * TX_PEAK_FSK;
dsp_tone_bit[1][1][i] = -s * TX_PEAK_FSK; dsp_tone_bit[1][1][i] = -s * TX_PEAK_FSK;
/* bit(0) 1.5 cycles */ /* bit(0) 1.5 cycles */
s = sin((double)i / 256.0 * 3.0 * PI); s = sin((double)i / 65536.0 * 3.0 * PI);
dsp_tone_bit[0][0][i] = s * TX_PEAK_FSK; dsp_tone_bit[0][0][i] = s * TX_PEAK_FSK;
dsp_tone_bit[1][0][i] = -s * TX_PEAK_FSK; dsp_tone_bit[1][0][i] = -s * TX_PEAK_FSK;
} }
@ -115,9 +128,8 @@ int dsp_init_sender(nmt_t *nmt)
PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Init DSP for Transceiver.\n"); PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Init DSP for Transceiver.\n");
/* set deviation and modulation parameters */ /* set modulation parameters */
nmt->sender.bandwidth = BANDWIDTH; sender_set_fm(&nmt->sender, MAX_DEVIATION, MAX_MODULATION, DBM0_DEVIATION, MAX_DISPLAY);
nmt->sender.sample_deviation = 2500.0 / (double)TX_PEAK_FSK; // FIXME: calc real value
PDEBUG(DDSP, DEBUG_DEBUG, "Using FSK level of %.0f (3.5 KHz deviation @ 1500 Hz)\n", TX_PEAK_FSK); PDEBUG(DDSP, DEBUG_DEBUG, "Using FSK level of %.0f (3.5 KHz deviation @ 1500 Hz)\n", TX_PEAK_FSK);
PDEBUG(DDSP, DEBUG_DEBUG, "Using Supervisory level of %.0f (0.3 KHz deviation @ 4015 Hz)\n", TX_PEAK_SUPER); PDEBUG(DDSP, DEBUG_DEBUG, "Using Supervisory level of %.0f (0.3 KHz deviation @ 4015 Hz)\n", TX_PEAK_SUPER);
@ -166,22 +178,22 @@ int dsp_init_sender(nmt_t *nmt)
/* count symbols */ /* count symbols */
for (i = 0; i < 2; i++) for (i = 0; i < 2; i++)
audio_goertzel_init(&nmt->fsk_goertzel[i], fsk_freq[i], nmt->sender.samplerate); audio_goertzel_init(&nmt->fsk_goertzel[i], fsk_freq[i], nmt->sender.samplerate);
nmt->fsk_phaseshift256 = 256.0 / nmt->fsk_samples_per_bit; nmt->fsk_phaseshift65536 = 65536.0 / nmt->fsk_samples_per_bit;
PDEBUG(DDSP, DEBUG_DEBUG, "fsk_phaseshift = %.4f\n", nmt->fsk_phaseshift256); PDEBUG(DDSP, DEBUG_DEBUG, "fsk_phaseshift = %.4f\n", nmt->fsk_phaseshift65536);
/* count supervidory tones */ /* count supervidory tones */
for (i = 0; i < 5; i++) { for (i = 0; i < 5; i++) {
audio_goertzel_init(&nmt->super_goertzel[i], super_freq[i], nmt->sender.samplerate); audio_goertzel_init(&nmt->super_goertzel[i], super_freq[i], nmt->sender.samplerate);
if (i < 4) { if (i < 4) {
nmt->super_phaseshift256[i] = 256.0 / ((double)nmt->sender.samplerate / super_freq[i]); nmt->super_phaseshift65536[i] = 65536.0 / ((double)nmt->sender.samplerate / super_freq[i]);
PDEBUG(DDSP, DEBUG_DEBUG, "super_phaseshift[%d] = %.4f\n", i, nmt->super_phaseshift256[i]); PDEBUG(DDSP, DEBUG_DEBUG, "super_phaseshift[%d] = %.4f\n", i, nmt->super_phaseshift65536[i]);
} }
} }
super_reset(nmt); super_reset(nmt);
/* dial tone */ /* dial tone */
nmt->dial_phaseshift256 = 256.0 / ((double)nmt->sender.samplerate / DIALTONE_HZ); nmt->dial_phaseshift65536 = 65536.0 / ((double)nmt->sender.samplerate / DIALTONE_HZ);
PDEBUG(DDSP, DEBUG_DEBUG, "dial_phaseshift = %.4f\n", nmt->dial_phaseshift256); PDEBUG(DDSP, DEBUG_DEBUG, "dial_phaseshift = %.4f\n", nmt->dial_phaseshift65536);
/* dtmf */ /* dtmf */
dtmf_init(&nmt->dtmf, 8000); dtmf_init(&nmt->dtmf, 8000);
@ -305,9 +317,8 @@ static inline void fsk_decode_step(nmt_t *nmt, int pos)
level = audio_level(spl, max); level = audio_level(spl, max);
/* limit level to prevent division by zero */ /* limit level to prevent division by zero */
if (level < 0.01) if (level < 0.001)
level = 0.01; level = 0.001;
// level = 0.63662 / 2.0;
audio_goertzel(nmt->fsk_goertzel, spl, max, pos, result, 2); audio_goertzel(nmt->fsk_goertzel, spl, max, pos, result, 2);
@ -353,9 +364,9 @@ static inline void fsk_decode_step(nmt_t *nmt, int pos)
printf("|%s|\n", debug_amplitude(quality)); printf("|%s|\n", debug_amplitude(quality));
#endif #endif
/* adjust level, so a peak level becomes 100% */ /* adjust level, so a peak level becomes 100% */
fsk_receive_bit(nmt, bit, quality, level / 0.63662 * 32768.0 / TX_PEAK_FSK); fsk_receive_bit(nmt, bit, quality, level / 0.63662 / TX_PEAK_FSK);
if (nmt->dms_call) if (nmt->dms_call)
fsk_receive_bit_dms(nmt, bit, quality, level / 0.63662 * 32768.0 / TX_PEAK_FSK); fsk_receive_bit_dms(nmt, bit, quality, level / 0.63662 / TX_PEAK_FSK);
nmt->fsk_filter_sample = 10; nmt->fsk_filter_sample = 10;
} }
} }
@ -368,26 +379,19 @@ static void super_decode(nmt_t *nmt, sample_t *samples, int length)
audio_goertzel(&nmt->super_goertzel[nmt->supervisory - 1], samples, length, 0, &result[0], 1); audio_goertzel(&nmt->super_goertzel[nmt->supervisory - 1], samples, length, 0, &result[0], 1);
audio_goertzel(&nmt->super_goertzel[4], samples, length, 0, &result[1], 1); /* noise floor detection */ audio_goertzel(&nmt->super_goertzel[4], samples, length, 0, &result[1], 1); /* noise floor detection */
#if 0
/* normalize levels */
result[0] *= 32768.0 / TX_PEAK_SUPER / 0.63662;
result[1] *= 32768.0 / TX_PEAK_SUPER / 0.63662;
printf("signal=%.4f noise=%.4f\n", result[0], result[1]);
#endif
quality = (result[0] - result[1]) / result[0]; quality = (result[0] - result[1]) / result[0];
if (quality < 0) if (quality < 0)
quality = 0; quality = 0;
if (nmt->state == STATE_ACTIVE) if (nmt->state == STATE_ACTIVE)
PDEBUG_CHAN(DDSP, DEBUG_NOTICE, "Supervisory level %.0f%% quality %.0f%%\n", result[0] / 0.63662 * 32768.0 / TX_PEAK_SUPER * 100.0, quality * 100.0); PDEBUG_CHAN(DDSP, DEBUG_NOTICE, "Supervisory level %.0f%% quality %.0f%%\n", result[0] / 0.63662 / TX_PEAK_SUPER * 100.0, quality * 100.0);
if (quality > 0.5) { if (quality > 0.5) {
if (nmt->super_detected == 0) { if (nmt->super_detected == 0) {
nmt->super_detect_count++; nmt->super_detect_count++;
if (nmt->super_detect_count == SUPER_DETECT_COUNT) { if (nmt->super_detect_count == SUPER_DETECT_COUNT) {
nmt->super_detected = 1; nmt->super_detected = 1;
nmt->super_detect_count = 0; nmt->super_detect_count = 0;
PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Supervisory signal detected with level=%.0f%%, quality=%.0f%%.\n", result[0] / 0.63662 * 32768.0 / TX_PEAK_SUPER * 100.0, quality * 100.0); PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Supervisory signal detected with level=%.0f%%, quality=%.0f%%.\n", result[0] / 0.63662 / TX_PEAK_SUPER * 100.0, quality * 100.0);
nmt_rx_super(nmt, 1, quality); nmt_rx_super(nmt, 1, quality);
} }
} else } else
@ -497,21 +501,21 @@ int fsk_render_frame(nmt_t *nmt, const char *frame, int length, sample_t *sample
int count = 0, i; int count = 0, i;
polarity = nmt->fsk_polarity; polarity = nmt->fsk_polarity;
phaseshift = nmt->fsk_phaseshift256; phaseshift = nmt->fsk_phaseshift65536;
phase = nmt->fsk_phase256; phase = nmt->fsk_phase65536;
for (i = 0; i < length; i++) { for (i = 0; i < length; i++) {
bit = (frame[i] == '1'); bit = (frame[i] == '1');
do { do {
*sample++ = dsp_tone_bit[polarity][bit][(uint8_t)phase]; *sample++ = dsp_tone_bit[polarity][bit][(uint16_t)phase];
count++; count++;
phase += phaseshift; phase += phaseshift;
} while (phase < 256.0); } while (phase < 65536.0);
phase -= 256.0; phase -= 65536.0;
/* flip polarity when we have 1.5 sine waves */ /* flip polarity when we have 1.5 sine waves */
if (bit == 0) if (bit == 0)
polarity = 1 - polarity; polarity = 1 - polarity;
} }
nmt->fsk_phase256 = phase; nmt->fsk_phase65536 = phase;
nmt->fsk_polarity = polarity; nmt->fsk_polarity = polarity;
/* return number of samples created for frame */ /* return number of samples created for frame */
@ -570,17 +574,17 @@ static void super_encode(nmt_t *nmt, sample_t *samples, int length)
double phaseshift, phase; double phaseshift, phase;
int i; int i;
phaseshift = nmt->super_phaseshift256[nmt->supervisory - 1]; phaseshift = nmt->super_phaseshift65536[nmt->supervisory - 1];
phase = nmt->super_phase256; phase = nmt->super_phase65536;
for (i = 0; i < length; i++) { for (i = 0; i < length; i++) {
*samples++ += dsp_sine_super[(uint8_t)phase]; *samples++ += dsp_sine_super[(uint16_t)phase];
phase += phaseshift; phase += phaseshift;
if (phase >= 256) if (phase >= 65536)
phase -= 256; phase -= 65536;
} }
nmt->super_phase256 = phase; nmt->super_phase65536 = phase;
} }
/* Generate audio stream from dial tone. Keep phase for next call of function. */ /* Generate audio stream from dial tone. Keep phase for next call of function. */
@ -589,17 +593,17 @@ static void dial_tone(nmt_t *nmt, sample_t *samples, int length)
double phaseshift, phase; double phaseshift, phase;
int i; int i;
phaseshift = nmt->dial_phaseshift256; phaseshift = nmt->dial_phaseshift65536;
phase = nmt->dial_phase256; phase = nmt->dial_phase65536;
for (i = 0; i < length; i++) { for (i = 0; i < length; i++) {
*samples++ = dsp_sine_dialtone[(uint8_t)phase]; *samples++ = dsp_sine_dialtone[(uint16_t)phase];
phase += phaseshift; phase += phaseshift;
if (phase >= 256) if (phase >= 65536)
phase -= 256; phase -= 65536;
} }
nmt->dial_phase256 = phase; nmt->dial_phase65536 = phase;
} }
/* Provide stream of audio toward radio unit */ /* Provide stream of audio toward radio unit */

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@ -1452,7 +1452,7 @@ void nmt_receive_frame(nmt_t *nmt, const char *bits, double quality, double leve
frame_t frame; frame_t frame;
int rc; int rc;
PDEBUG_CHAN(DDSP, DEBUG_INFO, "RX Level: %.0f%% Quality=%.0f\n", level * 100.0 + 0.5, quality * 100.0 + 0.5); PDEBUG_CHAN(DDSP, DEBUG_INFO, "RX Level: %.0f%% Quality=%.0f\n", level * 100.0, quality * 100.0);
rc = decode_frame(&frame, bits, (nmt->sender.loopback) ? MTX_TO_XX : XX_TO_MTX, (nmt->state == STATE_MT_PAGING)); rc = decode_frame(&frame, bits, (nmt->sender.loopback) ? MTX_TO_XX : XX_TO_MTX, (nmt->state == STATE_MT_PAGING));
if (rc < 0) { if (rc < 0) {

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@ -113,12 +113,12 @@ typedef struct nmt {
double fsk_filter_quality[256];/* quality infos */ double fsk_filter_quality[256];/* quality infos */
sample_t *super_filter_spl; /* array with sample buffer for supervisory detection */ sample_t *super_filter_spl; /* array with sample buffer for supervisory detection */
int super_filter_pos; /* current sample position in filter_spl */ int super_filter_pos; /* current sample position in filter_spl */
double super_phaseshift256[4]; /* how much the phase of sine wave changes per sample */ double super_phaseshift65536[4];/* how much the phase of sine wave changes per sample */
double super_phase256; /* current phase */ double super_phase65536; /* current phase */
double dial_phaseshift256; /* how much the phase of sine wave changes per sample */ double dial_phaseshift65536; /* how much the phase of sine wave changes per sample */
double dial_phase256; /* current phase */ double dial_phase65536; /* current phase */
double fsk_phaseshift256; /* how much the phase of fsk synbol changes per sample */ double fsk_phaseshift65536; /* how much the phase of fsk synbol changes per sample */
double fsk_phase256; /* current phase */ double fsk_phase65536; /* current phase */
sample_t *frame_spl; /* samples to store a complete rendered frame */ sample_t *frame_spl; /* samples to store a complete rendered frame */
int frame_size; /* total size of sample buffer */ int frame_size; /* total size of sample buffer */
int frame_length; /* current length of data in sample buffer */ int frame_length; /* current length of data in sample buffer */

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@ -12,7 +12,7 @@
#define SAMPLERATE 48000 #define SAMPLERATE 48000
static double get_level(double *samples) static double get_level(sample_t *samples)
{ {
int i; int i;
double envelope = 0; double envelope = 0;
@ -24,7 +24,7 @@ static double get_level(double *samples)
return envelope; return envelope;
} }
static void gen_samples(double *samples, double freq) static void gen_samples(sample_t *samples, double freq)
{ {
int i; int i;
double value; double value;
@ -39,7 +39,7 @@ int main(void)
{ {
emphasis_t estate; emphasis_t estate;
double cut_off = CUT_OFF_EMPHASIS_DEFAULT; double cut_off = CUT_OFF_EMPHASIS_DEFAULT;
double samples[SAMPLERATE]; sample_t samples[SAMPLERATE];
double level; double level;
double i; double i;

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@ -11,7 +11,7 @@
#define SAMPLERATE 48000 #define SAMPLERATE 48000
static double get_level(double *samples) static double get_level(sample_t *samples)
{ {
int i; int i;
double envelope = 0; double envelope = 0;
@ -23,7 +23,7 @@ static double get_level(double *samples)
return envelope; return envelope;
} }
static void gen_samples(double *samples, double freq) static void gen_samples(sample_t *samples, double freq)
{ {
int i; int i;
double value; double value;
@ -38,7 +38,7 @@ int main(void)
{ {
filter_t filter_low; filter_t filter_low;
filter_t filter_high; filter_t filter_high;
double samples[SAMPLERATE]; sample_t samples[SAMPLERATE];
double level; double level;
int iter = 2; int iter = 2;
int i; int i;