kopia lustrzana https://github.com/rs1729/RS
rs41iq: freq-shift memfix, snr
Zilog80
rodzic
e43d074965
commit
27283be3ed
|
|
@ -127,7 +127,8 @@ ui8_t mask[MASK_LEN] = { 0x96, 0x83, 0x3E, 0x51, 0xB1, 0x49, 0x08, 0x98,
|
|||
int LOG2N;
|
||||
int N_DFT, M_DFT;
|
||||
int N_IQBUF;
|
||||
double complex *iqbuf = NULL;
|
||||
double complex *raw_iqbuf = NULL;
|
||||
double complex *rot_iqbuf = NULL;
|
||||
|
||||
|
||||
int Nvar = 0;
|
||||
|
|
@ -252,8 +253,14 @@ int read_csample(FILE *fp, double complex *z) {
|
|||
|
||||
int sample_head_start = 0;
|
||||
int sample_framestart = 0;
|
||||
int sample_posnoise = 0;
|
||||
double df = 0.0;
|
||||
|
||||
int len_sq = 0;
|
||||
double V_noise = 0.0;
|
||||
double V_signal = 0.0;
|
||||
double SNRdB = 0.0;
|
||||
|
||||
int read_signed_sample(FILE *fp, double *s) { // int = i32_t
|
||||
double x=0, x0=0;
|
||||
double complex z, w;
|
||||
|
|
@ -261,14 +268,43 @@ int read_signed_sample(FILE *fp, double *s) { // int = i32_t
|
|||
double gain = 1.0;
|
||||
|
||||
if (option_iq) {
|
||||
|
||||
if ( read_csample(fp, &z) == EOF ) return EOF;
|
||||
raw_iqbuf[sample_count % N_IQBUF] = z;
|
||||
double t = (double)(sample_count) / sample_rate;
|
||||
|
||||
z *= cexp(-t*2*M_PI*df*I);
|
||||
w = z * conj(z0);
|
||||
x = gain * carg(w)/M_PI; // d1
|
||||
//x = _gain * cimag(w) / (cabs(z0)*cabs(z0)); // for small angles ... d2
|
||||
z0 = z;
|
||||
iqbuf[sample_count % N_IQBUF] = z;
|
||||
rot_iqbuf[sample_count % N_IQBUF] = z;
|
||||
|
||||
if (sample_posnoise > 0)
|
||||
{
|
||||
if (sample_count >= sample_framestart && sample_count < sample_framestart+len_sq) {
|
||||
if (sample_count == sample_framestart) V_signal = 0.0;
|
||||
V_signal += cabs(z);
|
||||
}
|
||||
if (sample_count == sample_framestart+len_sq) V_signal /= (double)len_sq;
|
||||
|
||||
if (sample_count >= sample_posnoise && sample_count < sample_posnoise+len_sq) {
|
||||
if (sample_count == sample_posnoise) V_noise = 0.0;
|
||||
V_noise += cabs(z);
|
||||
}
|
||||
if (sample_count == sample_posnoise+len_sq) {
|
||||
V_noise = V_noise/(double)len_sq;
|
||||
#if defined(DBG) || defined(DBG1)
|
||||
if (V_signal > 0 && V_noise > 0) {
|
||||
// iq-samples/V [-1..1]
|
||||
// dBw = 2*dBv, P=c*U*U
|
||||
// dBw = 2*10*log10(V/V0)
|
||||
SNRdB = 20.0 * log10(V_signal/V_noise+1e-20);
|
||||
fprintf(stderr, "SNR: %.2f dB\n", SNRdB);
|
||||
}
|
||||
#endif
|
||||
}
|
||||
}
|
||||
|
||||
#ifdef DBG1
|
||||
if ( sample_framestart > 0 && sample_count >= (unsigned long)sample_framestart &&
|
||||
|
|
@ -380,7 +416,7 @@ int read_rawbit(FILE *fp, int *bit) {
|
|||
double f2 = -f1;
|
||||
while (n > 0) {
|
||||
t = -n / (double)sample_rate;
|
||||
z = iqbuf[(sample_count-n + N_IQBUF) % N_IQBUF];
|
||||
z = rot_iqbuf[(sample_count-n + N_IQBUF) % N_IQBUF];
|
||||
X1 += z*cexp(-t*2*M_PI*f1*I);
|
||||
X2 += z*cexp(-t*2*M_PI*f2*I);
|
||||
n--;
|
||||
|
|
@ -392,7 +428,7 @@ int read_rawbit(FILE *fp, int *bit) {
|
|||
double complex x1 = xi1;
|
||||
double complex x2 = xi2;
|
||||
while (n > 0) {
|
||||
z = iqbuf[(sample_count-n + N_IQBUF) % N_IQBUF];
|
||||
z = rot_iqbuf[(sample_count-n + N_IQBUF) % N_IQBUF];
|
||||
X1 += z*x1; x1 *= xi1;
|
||||
X2 += z*x2; x2 *= xi2;
|
||||
n--;
|
||||
|
|
@ -426,8 +462,8 @@ int init_dft() {
|
|||
int i, k, n;
|
||||
int WLEN = M_DFT;
|
||||
|
||||
xn = calloc(N_DFT, sizeof(complex double)); if (xn == NULL) return -1;
|
||||
Z = calloc(N_DFT, sizeof(complex double)); if (Z == NULL) return -1;
|
||||
xn = calloc(N_DFT, sizeof(complex double)); if (xn == NULL) return -1;
|
||||
Z = calloc(N_DFT, sizeof(complex double)); if (Z == NULL) return -1;
|
||||
ew = calloc(LOG2N, sizeof(complex double)); if (ew == NULL) return -1;
|
||||
db = calloc(N_DFT, sizeof(double)); if (db == NULL) return -1;
|
||||
|
||||
|
|
@ -1695,8 +1731,10 @@ int main(int argc, char *argv[]) {
|
|||
N_DFT = (1 << LOG2N);
|
||||
init_dft();
|
||||
N_IQBUF = M_DFT + samples_per_bit*(64+16);
|
||||
iqbuf = calloc(N_IQBUF+1, sizeof(complex double)); if (iqbuf == NULL) return -1;
|
||||
raw_iqbuf = calloc(N_IQBUF+1, sizeof(complex double)); if (raw_iqbuf == NULL) return -1;
|
||||
rot_iqbuf = calloc(N_IQBUF+1, sizeof(complex double)); if (rot_iqbuf == NULL) return -1;
|
||||
|
||||
len_sq = samples_per_bit*8;
|
||||
}
|
||||
|
||||
if (option_b)
|
||||
|
|
@ -1732,7 +1770,7 @@ int main(int argc, char *argv[]) {
|
|||
int buf_start = sample_count - (HEADOFS+HEADLEN+(len-i)+256)*samples_per_bit;
|
||||
while (buf_start < 0) buf_start += N_IQBUF;
|
||||
for (j = 0; j < M_DFT; j++) {
|
||||
xn[j] = Hann[j]*iqbuf[(buf_start+j) % N_IQBUF]; // Hann[j]*buffer[(ptr + j + 1)%N];
|
||||
xn[j] = Hann[j]*raw_iqbuf[(buf_start+j) % N_IQBUF]; // Hann[j]*buffer[(ptr + j + 1)%N];
|
||||
}
|
||||
dft2();
|
||||
db_power(Z, db);
|
||||
|
|
@ -1743,8 +1781,9 @@ int main(int argc, char *argv[]) {
|
|||
if (fabs(df) > 1000.0) df = 0.0;
|
||||
sample_head_start = sample_count - (HEADOFS+HEADLEN+(len-i-1))*samples_per_bit;
|
||||
sample_framestart = sample_head_start + 64*samples_per_bit;
|
||||
double phase0 = carg(iqbuf[sample_head_start % N_IQBUF]);
|
||||
sample_posnoise = sample_framestart + sample_rate*7/8.0;
|
||||
#ifdef DBG1
|
||||
double phase0 = carg(rot_iqbuf[sample_head_start % N_IQBUF]);
|
||||
fprintf(stderr, "%lu phase0 : %+.2f\n", sample_count, phase0/M_PI);
|
||||
#endif
|
||||
}
|
||||
|
|
@ -1818,7 +1857,8 @@ int main(int argc, char *argv[]) {
|
|||
}
|
||||
if (option_iq)
|
||||
{
|
||||
if (iqbuf) { free(iqbuf); iqbuf = NULL; }
|
||||
if (raw_iqbuf) { free(raw_iqbuf); raw_iqbuf = NULL; }
|
||||
if (rot_iqbuf) { free(rot_iqbuf); rot_iqbuf = NULL; }
|
||||
free_dft();
|
||||
}
|
||||
|
||||
|
|
|
|||
Ładowanie…
Reference in New Issue