cellular-infrastructure
/
osmocom-analog
8
1
Fork 2
Code Issues 10 Pull Requests 2 Projects Releases Wiki Activity

Add power control to AM (power on/off per sample)

pull/1/head
Andreas Eversberg 2019-12-05 21:57:23 +01:00
parent 150a77b69d
commit 4af2dca10d
4 changed files with 10 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
src/libam/am.c
View File

@ -91,7 +91,7 @@ void am_mod_exit(am_mod_t __attribute__((unused)) *mod)
{
}
void am_modulate_complex(am_mod_t *mod, sample_t *amplitude, int num, float *baseband)
void am_modulate_complex(am_mod_t *mod, sample_t *amplitude, uint8_t *power, int num, float *baseband)
{
int s;
double vector;
@ -101,7 +101,10 @@ void am_modulate_complex(am_mod_t *mod, sample_t *amplitude, int num, float *bas
double bias = mod->bias;
for (s = 0; s < num; s++) {
vector = *amplitude++ * gain + bias;
if (*power++)
vector = *amplitude++ * gain + bias;
else
vector = 0.0;
if (fast_math) {
*baseband++ += cos_tab[(uint16_t)phase] * vector;
*baseband++ += sin_tab[(uint16_t)phase] * vector;

2
src/libam/am.h
View File

@ -12,7 +12,7 @@ typedef struct am_mod {
int am_mod_init(am_mod_t *mod, double samplerate, double offset, double gain, double bias);
void am_mod_exit(am_mod_t *mod);
void am_modulate_complex(am_mod_t *mod, sample_t *amplitude, int num, float *baseband);
void am_modulate_complex(am_mod_t *mod, sample_t *amplitude, uint8_t *power, int num, float *baseband);
typedef struct am_demod {
double rot; /* angle to rotate vector per sample */

3
src/libsdr/sdr.c
View File

@ -775,8 +775,7 @@ int sdr_write(void *inst, sample_t **samples, uint8_t **power, int num, enum pag
if (on[c] && sdr->paging_channel)
fm_modulate_complex(&sdr->chan[sdr->paging_channel].fm_mod, samples[c], power[c], num, buff);
else if (sdr->chan[c].am) {
if (power[c][0])
am_modulate_complex(&sdr->chan[c].am_mod, samples[c], num, buff);
am_modulate_complex(&sdr->chan[c].am_mod, samples[c], power[c], num, buff);
} else
fm_modulate_complex(&sdr->chan[c].fm_mod, samples[c], power[c], num, buff);
}

6
src/radio/radio.c
View File

@ -546,12 +546,12 @@ int radio_tx(radio_t *radio, float *baseband, int signal_num)
/* prepare baseband */
memset(baseband, 0, sizeof(float) * 2 * signal_num);
memset(signal_power, 1, signal_num);
/* filter audio (remove DC, remove high frequencies, pre-emphasis)
* and modulate */
switch (radio->modulation) {
case MODULATION_FM:
memset(signal_power, 1, signal_num);
pre_emphasis(&radio->fm_emphasis[0], signal_samples[0], signal_num);
clipper_process(signal_samples[0], signal_num);
if (radio->stereo) {
@ -577,14 +577,14 @@ int radio_tx(radio_t *radio, float *baseband, int signal_num)
/* also clip to prevent overshooting after audio filtering */
clipper_process(signal_samples[0], signal_num);
iir_process(&radio->tx_am_bw_limit, signal_samples[0], signal_num);
am_modulate_complex(&radio->am_mod, signal_samples[0], signal_num, baseband);
am_modulate_complex(&radio->am_mod, signal_samples[0], signal_power, signal_num, baseband);
break;
case MODULATION_AM_USB:
case MODULATION_AM_LSB:
/* also clip to prevent overshooting after audio filtering */
clipper_process(signal_samples[0], signal_num);
iir_process(&radio->tx_am_bw_limit, signal_samples[0], signal_num);
am_modulate_complex(&radio->am_mod, signal_samples[0], signal_num, baseband);
am_modulate_complex(&radio->am_mod, signal_samples[0], signal_power, signal_num, baseband);
break;
default:
break;