caiyu/gps-sdr-sim
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Add 1-bit I/Q data format to reduce output file size

Browse Source
This commit is contained in:
OSQZSS 2015-12-29 11:40:46 +09:00
parent 88647f482e
commit 0106011ce3
1 changed files with 34 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

41
gpssim.c
View File

@ -76,6 +76,7 @@ typedef int bool;
#define CARR_TO_CODE (1.0/1540.0)
// Sampling data format
#define SC01 (1)
#define SC08 (8)
#define SC16 (16)
@ -1536,8 +1537,8 @@ void usage(void)
" -d <duration> Duration [sec] (max: %.0f)\n"
" -o <output> I/Q sampling data file (default: gpssim.bin)\n"
" -s <frequency> Sampling frequency [Hz] (default: 2600000)\n"
" -b <iq_bits> I/Q data format [8/16] (default: 16)\n"
" -v <verbose> Show details about simulated channels\n",
" -b <iq_bits> I/Q data format [1/8/16] (default: 16)\n"
" -v Show details about simulated channels\n",
((double)USER_MOTION_SIZE)/10.0);
return;
@ -1658,7 +1659,7 @@ int main(int argc, char *argv[])
break;
case 'b':
data_format = atoi(optarg);
if (data_format!=SC08 && data_format!=SC16)
if (data_format!=SC01 && data_format!=SC08 && data_format!=SC16)
{
printf("ERROR: Invalid I/Q data format.\n");
exit(1);
@ -1856,7 +1857,7 @@ int main(int argc, char *argv[])
if (iq_buff==NULL)
{
printf("ERROR: Faild to allocate IQ buffer.\n");
printf("ERROR: Faild to allocate 16-bit I/Q buffer.\n");
exit(1);
}
@ -1865,7 +1866,16 @@ int main(int argc, char *argv[])
iq8_buff = calloc(2*iq_buff_size, 1);
if (iq8_buff==NULL)
{
printf("ERROR: Faild to allocate IQ buffer.\n");
printf("ERROR: Faild to allocate 8-bit I/Q buffer.\n");
exit(1);
}
}
else if (data_format==SC01)
{
iq8_buff = calloc(iq_buff_size/4, 1); // byte = {I0, Q0, I1, Q1, I2, Q2, I3, Q3}
if (iq8_buff==NULL)
{
printf("ERROR: Faild to allocate compressed 1-bit I/Q buffer.\n");
exit(1);
}
}
@ -2009,15 +2019,32 @@ int main(int argc, char *argv[])
} // End of omp parallel for
if (data_format==SC08)
if (data_format==SC01)
{
for (isamp=0; isamp<2*iq_buff_size; isamp++)
{
if (isamp%8==0)
iq8_buff[isamp/8] = 0x00;
iq8_buff[isamp/8] |= (iq_buff[isamp]>0?0x01:0x00)<<(7-isamp%8);
}
fwrite(iq8_buff, 1, iq_buff_size/4, fp);
}
else if (data_format==SC08)
{
for (isamp=0; isamp<2*iq_buff_size; isamp++)
iq8_buff[isamp] = iq_buff[isamp]>>4; // 12-bit bladeRF -> 8-bit HackRF
fwrite(iq8_buff, 1, 2*iq_buff_size, fp);
}
else
else // data_format==SC16
{
for (isamp=0; isamp<2*iq_buff_size; isamp++)
iq_buff[isamp] = iq_buff[isamp]>0?1000:-1000; // Emulated 1-bit I/Q
fwrite(iq_buff, 2, 2*iq_buff_size, fp);
}
//
// Update navigation message and channel allocation every 30 seconds