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Faster carrier signal generation

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OSQZSS 2015-11-29 13:05:32 +09:00
parent 84f1c29f93
commit 38c5245484
1 changed files with 29 additions and 31 deletions
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60
gpssim.c
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@ -225,7 +225,7 @@ typedef struct
double f_carr; /*< Carrier frequency */ double f_carr; /*< Carrier frequency */
double f_code; /*< Code frequency */ double f_code; /*< Code frequency */
unsigned int carr_phase; /*< Carrier phase */ unsigned int carr_phase; /*< Carrier phase */
int carr_phasestep; /*< Carrier phasestep */ int carr_phasestep; /*< Carrier phasestep */
double code_phase; /*< Code phase */ double code_phase; /*< Code phase */
gpstime_t g0; /*!< GPS time at start */ gpstime_t g0; /*!< GPS time at start */
unsigned long dwrd[N_DWRD]; /*!< Data words of sub-frame */ unsigned long dwrd[N_DWRD]; /*!< Data words of sub-frame */
@ -1570,22 +1570,22 @@ int main(int argc, char *argv[])
//////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////
// Allocate I/Q buffer // Allocate I/Q buffer
iq_buff = calloc(2*iq_buff_size, 2); iq_buff = calloc(2*iq_buff_size, 2);
if (iq_buff==NULL) if (iq_buff==NULL)
{ {
printf("Faild to allocate IQ buffer.\n"); printf("Faild to allocate IQ buffer.\n");
exit(1); exit(1);
} }
if (data_format==SC08) if (data_format==SC08)
{ {
iq8_buff = calloc(2*iq_buff_size, 1); iq8_buff = calloc(2*iq_buff_size, 1);
if (iq8_buff==NULL) if (iq8_buff==NULL)
{ {
printf("Faild to allocate IQ buffer.\n"); printf("Faild to allocate IQ buffer.\n");
exit(1); exit(1);
} }
} }
// Open output file // Open output file
if (NULL==(fp=fopen(outfile,"wb"))) if (NULL==(fp=fopen(outfile,"wb")))
@ -1624,8 +1624,8 @@ int main(int argc, char *argv[])
r_xyz = tmp.range; r_xyz = tmp.range;
phase_ini = (2.0*r_ref - r_xyz)/LAMBDA_L1; phase_ini = (2.0*r_ref - r_xyz)/LAMBDA_L1;
phase_ini -= floor(phase_ini); phase_ini -= floor(phase_ini);
chan[i].carr_phase = 512 * 65536.0 * phase_ini; chan[i].carr_phase = (unsigned int)(512 * 65536.0 * phase_ini);
} }
//////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////
@ -1695,8 +1695,6 @@ int main(int argc, char *argv[])
for (iumd=1; iumd<numd; iumd++) for (iumd=1; iumd<numd; iumd++)
{ {
//#pragma omp parallel for private(isamp) // !!!FIXME!!! The current code runs faster without OpenMP support
// Properties -> Configuration Properties -> C/C++ -> Language -> Open MP Support -> Yes (/openmp)
for (i=0; i<nsat; i++) for (i=0; i<nsat; i++)
{ {
// Refresh code phase and data bit counters // Refresh code phase and data bit counters
@ -1708,27 +1706,27 @@ int main(int argc, char *argv[])
// Update code phase and data bit counters // Update code phase and data bit counters
computeCodePhase(&chan[i], rho0[sv], rho, 0.1); computeCodePhase(&chan[i], rho0[sv], rho, 0.1);
chan[i].carr_phasestep = 512 * 65536.0 * chan[i].f_carr * delt; chan[i].carr_phasestep = (int)(512 * 65536.0 * chan[i].f_carr * delt);
// Save current pseudorange // Save current pseudorange
rho0[sv] = rho; rho0[sv] = rho;
} }
for (isamp=0; isamp<iq_buff_size; isamp++) for (isamp=0; isamp<iq_buff_size; isamp++)
{ {
int i_acc = 0; int i_acc = 0;
int q_acc = 0; int q_acc = 0;
for (i=0; i<nsat; i++) for (i=0; i<nsat; i++)
{ {
#ifdef _SINE_LUT #ifdef _SINE_LUT
iTable = (chan[i].carr_phase >> 16) & 511; iTable = (chan[i].carr_phase >> 16) & 511;
ip = chan[i].dataBit * chan[i].codeCA * cosTable512[iTable]; ip = chan[i].dataBit * chan[i].codeCA * cosTable512[iTable];
qp = chan[i].dataBit * chan[i].codeCA * sinTable512[iTable]; qp = chan[i].dataBit * chan[i].codeCA * sinTable512[iTable];
i_acc += ip; i_acc += ip;
q_acc += qp; q_acc += qp;
#else #else
ip = chan[i].dataBit * chan[i].codeCA * cos(2.0*PI*chan[i].carr_phase); ip = chan[i].dataBit * chan[i].codeCA * cos(2.0*PI*chan[i].carr_phase);
qp = chan[i].dataBit * chan[i].codeCA * sin(2.0*PI*chan[i].carr_phase); qp = chan[i].dataBit * chan[i].codeCA * sin(2.0*PI*chan[i].carr_phase);
@ -1769,17 +1767,17 @@ int main(int argc, char *argv[])
chan[i].carr_phase += chan[i].carr_phasestep; chan[i].carr_phase += chan[i].carr_phasestep;
} }
// Store I/Q samples into buffer // Store I/Q samples into buffer
iq_buff[isamp*2] = (short)i_acc; iq_buff[isamp*2] = (short)i_acc;
iq_buff[isamp*2+1] = (short)q_acc; iq_buff[isamp*2+1] = (short)q_acc;
} // End of omp parallel for } // End of omp parallel for
if (data_format==SC08) if (data_format==SC08)
{ {
for (isamp=0; isamp<2*iq_buff_size; isamp++) for (isamp=0; isamp<2*iq_buff_size; isamp++)
{ {
iq8_buff[isamp] = iq_buff[isamp]>>4; // 12-bit bladeRF -> 8-bit HackRF iq8_buff[isamp] = iq_buff[isamp]>>4; // 12-bit bladeRF -> 8-bit HackRF
} }
fwrite(iq8_buff, 1, 2*iq_buff_size, fp); fwrite(iq8_buff, 1, 2*iq_buff_size, fp);
} }