mirror of
https://github.com/f4exb/sdrangel.git
synced 2024-11-25 09:18:54 -05:00
328 lines
9.5 KiB
C++
328 lines
9.5 KiB
C++
/* amd.c
|
|
|
|
This file is part of a program that implements a Software-Defined Radio.
|
|
|
|
Copyright (C) 2012, 2013 Warren Pratt, NR0V
|
|
Copyright (C) 2024 Edouard Griffiths, F4EXB Adapted to SDRangel
|
|
|
|
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 2
|
|
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, write to the Free Software
|
|
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
|
|
The author can be reached by email at
|
|
|
|
warren@wpratt.com
|
|
|
|
*/
|
|
|
|
#include <cmath>
|
|
|
|
#include "comm.hpp"
|
|
#include "amd.hpp"
|
|
#include "anf.hpp"
|
|
#include "emnr.hpp"
|
|
#include "anr.hpp"
|
|
#include "snba.hpp"
|
|
#include "RXA.hpp"
|
|
|
|
namespace WDSP {
|
|
|
|
AMD* AMD::create_amd
|
|
(
|
|
int run,
|
|
int buff_size,
|
|
float *in_buff,
|
|
float *out_buff,
|
|
int mode,
|
|
int levelfade,
|
|
int sbmode,
|
|
int sample_rate,
|
|
double fmin,
|
|
double fmax,
|
|
double zeta,
|
|
double omegaN,
|
|
double tauR,
|
|
double tauI
|
|
)
|
|
{
|
|
AMD *a = new AMD();
|
|
a->run = run;
|
|
a->buff_size = buff_size;
|
|
a->in_buff = in_buff;
|
|
a->out_buff = out_buff;
|
|
a->mode = mode;
|
|
a->levelfade = levelfade;
|
|
a->sbmode = sbmode;
|
|
a->sample_rate = (float)sample_rate;
|
|
a->fmin = fmin;
|
|
a->fmax = fmax;
|
|
a->zeta = zeta;
|
|
a->omegaN = omegaN;
|
|
a->tauR = tauR;
|
|
a->tauI = tauI;
|
|
|
|
init_amd(a);
|
|
return a;
|
|
}
|
|
|
|
void AMD::destroy_amd(AMD *a)
|
|
{
|
|
delete a;
|
|
}
|
|
|
|
void AMD::init_amd(AMD *a)
|
|
{
|
|
//pll
|
|
a->omega_min = 2 * M_PI * a->fmin / a->sample_rate;
|
|
a->omega_max = 2 * M_PI * a->fmax / a->sample_rate;
|
|
a->g1 = 1.0 - std::exp(-2.0 * a->omegaN * a->zeta / a->sample_rate);
|
|
a->g2 = -a->g1 + 2.0 * (1 - exp(-a->omegaN * a->zeta / a->sample_rate) * cos(a->omegaN / a->sample_rate * sqrt(1.0 - a->zeta * a->zeta)));
|
|
a->phs = 0.0;
|
|
a->fil_out = 0.0;
|
|
a->omega = 0.0;
|
|
|
|
//fade leveler
|
|
a->dc = 0.0;
|
|
a->dc_insert = 0.0;
|
|
a->mtauR = exp(-1.0 / (a->sample_rate * a->tauR));
|
|
a->onem_mtauR = 1.0 - a->mtauR;
|
|
a->mtauI = exp(-1.0 / (a->sample_rate * a->tauI));
|
|
a->onem_mtauI = 1.0 - a->mtauI;
|
|
|
|
//sideband separation
|
|
a->c0[0] = -0.328201924180698;
|
|
a->c0[1] = -0.744171491539427;
|
|
a->c0[2] = -0.923022915444215;
|
|
a->c0[3] = -0.978490468768238;
|
|
a->c0[4] = -0.994128272402075;
|
|
a->c0[5] = -0.998458978159551;
|
|
a->c0[6] = -0.999790306259206;
|
|
|
|
a->c1[0] = -0.0991227952747244;
|
|
a->c1[1] = -0.565619728761389;
|
|
a->c1[2] = -0.857467122550052;
|
|
a->c1[3] = -0.959123933111275;
|
|
a->c1[4] = -0.988739372718090;
|
|
a->c1[5] = -0.996959189310611;
|
|
a->c1[6] = -0.999282492800792;
|
|
}
|
|
|
|
void AMD::flush_amd (AMD *a)
|
|
{
|
|
a->dc = 0.0;
|
|
a->dc_insert = 0.0;
|
|
}
|
|
|
|
void AMD::xamd (AMD *a)
|
|
{
|
|
int i;
|
|
double audio;
|
|
double vco[2];
|
|
double corr[2];
|
|
double det;
|
|
double del_out;
|
|
double ai, bi, aq, bq;
|
|
double ai_ps, bi_ps, aq_ps, bq_ps;
|
|
int j, k;
|
|
|
|
if (a->run)
|
|
{
|
|
switch (a->mode)
|
|
{
|
|
|
|
case 0: //AM Demodulator
|
|
{
|
|
for (i = 0; i < a->buff_size; i++)
|
|
{
|
|
double xr = a->in_buff[2 * i + 0];
|
|
double xi = a->in_buff[2 * i + 1];
|
|
audio = sqrt(xr*xr + xi*xi);
|
|
|
|
if (a->levelfade)
|
|
{
|
|
a->dc = a->mtauR * a->dc + a->onem_mtauR * audio;
|
|
a->dc_insert = a->mtauI * a->dc_insert + a->onem_mtauI * audio;
|
|
audio += a->dc_insert - a->dc;
|
|
}
|
|
|
|
a->out_buff[2 * i + 0] = audio;
|
|
a->out_buff[2 * i + 1] = audio;
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
case 1: //Synchronous AM Demodulator with Sideband Separation
|
|
{
|
|
for (i = 0; i < a->buff_size; i++)
|
|
{
|
|
vco[0] = cos(a->phs);
|
|
vco[1] = sin(a->phs);
|
|
|
|
ai = a->in_buff[2 * i + 0] * vco[0];
|
|
bi = a->in_buff[2 * i + 0] * vco[1];
|
|
aq = a->in_buff[2 * i + 1] * vco[0];
|
|
bq = a->in_buff[2 * i + 1] * vco[1];
|
|
|
|
if (a->sbmode != 0)
|
|
{
|
|
a->a[0] = a->dsI;
|
|
a->b[0] = bi;
|
|
a->c[0] = a->dsQ;
|
|
a->d[0] = aq;
|
|
a->dsI = ai;
|
|
a->dsQ = bq;
|
|
|
|
for (j = 0; j < STAGES; j++)
|
|
{
|
|
k = 3 * j;
|
|
a->a[k + 3] = a->c0[j] * (a->a[k] - a->a[k + 5]) + a->a[k + 2];
|
|
a->b[k + 3] = a->c1[j] * (a->b[k] - a->b[k + 5]) + a->b[k + 2];
|
|
a->c[k + 3] = a->c0[j] * (a->c[k] - a->c[k + 5]) + a->c[k + 2];
|
|
a->d[k + 3] = a->c1[j] * (a->d[k] - a->d[k + 5]) + a->d[k + 2];
|
|
}
|
|
|
|
ai_ps = a->a[OUT_IDX];
|
|
bi_ps = a->b[OUT_IDX];
|
|
bq_ps = a->c[OUT_IDX];
|
|
aq_ps = a->d[OUT_IDX];
|
|
|
|
for (j = OUT_IDX + 2; j > 0; j--)
|
|
{
|
|
a->a[j] = a->a[j - 1];
|
|
a->b[j] = a->b[j - 1];
|
|
a->c[j] = a->c[j - 1];
|
|
a->d[j] = a->d[j - 1];
|
|
}
|
|
}
|
|
|
|
corr[0] = +ai + bq;
|
|
corr[1] = -bi + aq;
|
|
|
|
switch(a->sbmode)
|
|
{
|
|
case 0: //both sidebands
|
|
{
|
|
audio = corr[0];
|
|
break;
|
|
}
|
|
case 1: //LSB
|
|
{
|
|
audio = (ai_ps - bi_ps) + (aq_ps + bq_ps);
|
|
break;
|
|
}
|
|
case 2: //USB
|
|
{
|
|
audio = (ai_ps + bi_ps) - (aq_ps - bq_ps);
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (a->levelfade)
|
|
{
|
|
a->dc = a->mtauR * a->dc + a->onem_mtauR * audio;
|
|
a->dc_insert = a->mtauI * a->dc_insert + a->onem_mtauI * corr[0];
|
|
audio += a->dc_insert - a->dc;
|
|
}
|
|
|
|
a->out_buff[2 * i + 0] = audio;
|
|
a->out_buff[2 * i + 1] = audio;
|
|
|
|
if ((corr[0] == 0.0) && (corr[1] == 0.0))
|
|
corr[0] = 1.0;
|
|
|
|
det = atan2(corr[1], corr[0]);
|
|
del_out = a->fil_out;
|
|
a->omega += a->g2 * det;
|
|
|
|
if (a->omega < a->omega_min)
|
|
a->omega = a->omega_min;
|
|
|
|
if (a->omega > a->omega_max)
|
|
a->omega = a->omega_max;
|
|
|
|
a->fil_out = a->g1 * det + a->omega;
|
|
a->phs += del_out;
|
|
|
|
while (a->phs >= 2 * M_PI)
|
|
a->phs -= 2 * M_PI;
|
|
|
|
while (a->phs < 0.0)
|
|
a->phs += 2 * M_PI;
|
|
}
|
|
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
else if (a->in_buff != a->out_buff)
|
|
{
|
|
std::copy (a->in_buff, a->in_buff + a->buff_size * 2, a->out_buff);
|
|
}
|
|
}
|
|
|
|
void AMD::setBuffers_amd (AMD *a, float* in, float* out)
|
|
{
|
|
a->in_buff = in;
|
|
a->out_buff = out;
|
|
}
|
|
|
|
void AMD::setSamplerate_amd (AMD *a, int rate)
|
|
{
|
|
a->sample_rate = rate;
|
|
init_amd(a);
|
|
}
|
|
|
|
void AMD::setSize_amd (AMD *a, int size)
|
|
{
|
|
a->buff_size = size;
|
|
}
|
|
|
|
/********************************************************************************************************
|
|
* *
|
|
* RXA Properties *
|
|
* *
|
|
********************************************************************************************************/
|
|
|
|
void AMD::SetAMDRun(RXA& rxa, int run)
|
|
{
|
|
AMD *a = rxa.amd;
|
|
|
|
if (a->run != run)
|
|
{
|
|
RXA::bp1Check (
|
|
rxa,
|
|
run,
|
|
rxa.snba->run,
|
|
rxa.emnr->run,
|
|
rxa.anf->run,
|
|
rxa.anr->run
|
|
);
|
|
|
|
a->run = run;
|
|
RXA::bp1Set (rxa);
|
|
}
|
|
}
|
|
|
|
void AMD::SetAMDSBMode(RXA& rxa, int sbmode)
|
|
{
|
|
rxa.amd->sbmode = sbmode;
|
|
}
|
|
|
|
void AMD::SetAMDFadeLevel(RXA& rxa, int levelfade)
|
|
{
|
|
rxa.amd->levelfade = levelfade;
|
|
}
|
|
|
|
} // namesoace WDSP
|