kopia lustrzana https://github.com/rs1729/RS
dft_correlation window
Zilog80
rodzic
163b838795
commit
caf3065027
BIN
iq/iq_demod.pdf
BIN
iq/iq_demod.pdf
Plik binarny nie jest wyświetlany.
|
|
@ -15,7 +15,7 @@ typedef int i32_t;
|
|||
|
||||
static int option_verbose = 0, // ausfuehrliche Anzeige
|
||||
option_inv = 0, // invertiert Signal
|
||||
option_dc = 0,
|
||||
//option_dc = 0,
|
||||
option_silent = 0,
|
||||
wavloaded = 0;
|
||||
static int wav_channel = 0; // audio channel: left
|
||||
|
|
@ -76,11 +76,12 @@ static char c34_preheader[] =
|
|||
typedef struct {
|
||||
int bps; // header: here bps means baudrate ...
|
||||
int hLen;
|
||||
int N;
|
||||
int L;
|
||||
char *header;
|
||||
float BT;
|
||||
float spb;
|
||||
float thres;
|
||||
int herrs;
|
||||
float complex *Fm;
|
||||
char *type;
|
||||
ui8_t tn; // signed?
|
||||
|
|
@ -90,15 +91,15 @@ typedef struct {
|
|||
#define idxAB 7
|
||||
#define idxRS 8
|
||||
static rsheader_t rs_hdr[Nrs] = {
|
||||
{ 2500, 0, 0, dfm_header, 1.0, 0.0, 0.65, NULL, "DFM9", 2}, // DFM6: -2 (unsigned)
|
||||
{ 4800, 0, 0, rs41_header, 0.5, 0.0, 0.70, NULL, "RS41", 3},
|
||||
{ 4800, 0, 0, rs92_header, 0.5, 0.0, 0.70, NULL, "RS92", 4},
|
||||
{ 4800, 0, 0, lms6_header, 1.0, 0.0, 0.70, NULL, "LMS6", 8},
|
||||
{ 9600, 0, 0, m10_header, 1.0, 0.0, 0.76, NULL, "M10", 5},
|
||||
{ 5800, 0, 0, c34_preheader, 1.5, 0.0, 0.80, NULL, "C34C50", 9}, // C34/C50 2900 Hz tone
|
||||
{ 9600, 0, 0, imet_preamble, 0.5, 0.0, 0.80, NULL, "IMET", 6}, // IMET1AB=7, IMET1RS=8
|
||||
{ 9600, 0, 0, imet1ab_header, 1.0, 0.0, 0.80, NULL, "IMET1AB", 6},
|
||||
{ 9600, 0, 0, imet1rs_header, 0.5, 0.0, 0.80, NULL, "IMET1RS", 7} // IMET4
|
||||
{ 2500, 0, 0, dfm_header, 1.0, 0.0, 0.65, 2, NULL, "DFM9", 2}, // DFM6: -2 (unsigned)
|
||||
{ 4800, 0, 0, rs41_header, 0.5, 0.0, 0.70, 2, NULL, "RS41", 3},
|
||||
{ 4800, 0, 0, rs92_header, 0.5, 0.0, 0.70, 3, NULL, "RS92", 4},
|
||||
{ 4800, 0, 0, lms6_header, 1.0, 0.0, 0.70, 2, NULL, "LMS6", 8},
|
||||
{ 9616, 0, 0, m10_header, 1.0, 0.0, 0.76, 2, NULL, "M10", 5},
|
||||
{ 5800, 0, 0, c34_preheader, 1.5, 0.0, 0.80, 2, NULL, "C34C50", 9}, // C34/C50 2900 Hz tone
|
||||
{ 9600, 0, 0, imet_preamble, 0.5, 0.0, 0.80, 4, NULL, "IMET", 6}, // IMET1AB=7, IMET1RS=8
|
||||
{ 9600, 0, 0, imet1ab_header, 1.0, 0.0, 0.80, 2, NULL, "IMET1AB", 6},
|
||||
{ 9600, 0, 0, imet1rs_header, 0.5, 0.0, 0.80, 2, NULL, "IMET1RS", 7} // IMET4
|
||||
};
|
||||
|
||||
|
||||
|
|
@ -111,6 +112,7 @@ static rsheader_t rs_hdr[Nrs] = {
|
|||
// - pulse-shaping
|
||||
// m10: 00110011 at 9600 bps
|
||||
// rs41: 0 1 0 1 at 4800 bps
|
||||
// - after header, m10-baudrate < rs41-baudrate
|
||||
// - m10 top-carrier, fm-mean/average
|
||||
// - m10-header ..110(1)0110011()011.. bit shuffle
|
||||
// - m10 frame byte[1]=type(M2K2,M10,M10+)
|
||||
|
|
@ -128,7 +130,7 @@ static int wav_ch = 0; // 0: links bzw. mono; 1: rechts
|
|||
|
||||
static unsigned int sample_in, sample_out, delay;
|
||||
|
||||
static int M; // N
|
||||
static int M;
|
||||
|
||||
static float *bufs = NULL;
|
||||
|
||||
|
|
@ -229,60 +231,60 @@ static float get_bufmu(int ofs) {
|
|||
}
|
||||
|
||||
|
||||
static int getCorrDFT(int abs, int K, unsigned int pos, float *maxv, unsigned int *maxvpos, rsheader_t rshd) {
|
||||
static int getCorrDFT(int abs, int K, unsigned int pos, float *maxv, unsigned int *maxvpos, rsheader_t *rshd) {
|
||||
int i;
|
||||
int mp = -1;
|
||||
float mx = 0.0;
|
||||
float mx2 = 0.0;
|
||||
float re_cx = 0.0;
|
||||
double xnorm = 1;
|
||||
unsigned int mpos = 0;
|
||||
|
||||
dc = 0.0;
|
||||
|
||||
#ifdef ZEROPAD
|
||||
if (rshd.N + K > N_DFT/2 - 2) return -1;
|
||||
#else
|
||||
if (rshd.N + K > N_DFT) return -1;
|
||||
#endif
|
||||
// if (sample_in < delay+rshd.N+K) return -2;
|
||||
if (K + rshd->L > N_DFT) return -1;
|
||||
// if (sample_out < rshd->L) return -2; // nur falls K-4 < L
|
||||
|
||||
if (pos == 0) pos = sample_out;
|
||||
|
||||
|
||||
for (i = 0; i < rshd.N+K; i++) xn[i] = bufs[(pos+M -(rshd.N+K-1) + i) % M];
|
||||
for (i = 0; i < K+rshd->L; i++) xn[i] = bufs[(pos+M -(K+rshd->L-1) + i) % M];
|
||||
while (i < N_DFT) xn[i++] = 0.0;
|
||||
|
||||
dft(xn, X);
|
||||
|
||||
dc = get_bufmu(pos-sample_out); //oder: dc = creal(X[0])/N_DFT;
|
||||
dc = get_bufmu(pos-sample_out); //oder: dc = creal(X[0])/(K+rshd->L) = avg(xn) // zu lang (M10)
|
||||
|
||||
for (i = 0; i < N_DFT; i++) Z[i] = X[i]*rshd.Fm[i];
|
||||
for (i = 0; i < N_DFT; i++) Z[i] = X[i]*rshd->Fm[i];
|
||||
|
||||
Nidft(Z, cx);
|
||||
|
||||
|
||||
if (abs) {
|
||||
for (i = rshd.N; i < rshd.N+K; i++) {
|
||||
if (fabs(creal(cx[i])) > fabs(mx)) { // imag(cx)=0
|
||||
mx = creal(cx[i]);
|
||||
mp = i;
|
||||
}
|
||||
// relativ Peak - Normierung erst zum Schluss;
|
||||
// dann jedoch nicht zwingend corr-Max wenn FM-Amplitude bzw. norm(x) nicht konstant
|
||||
// (z.B. rs41 Signal-Pausen). Moeglicherweise wird dann wahres corr-Max in dem
|
||||
// K-Fenster nicht erkannt, deshalb K nicht zu gross waehlen.
|
||||
//
|
||||
mx2 = 0.0; // t = L-1
|
||||
for (i = rshd->L-1; i < K+rshd->L; i++) { // i=t .. i=t+K < t+1+K
|
||||
re_cx = creal(cx[i]); // imag(cx)=0
|
||||
//if (fabs(re_cx) > fabs(mx)) {
|
||||
if (re_cx*re_cx > mx2) {
|
||||
mx = re_cx;
|
||||
mx2 = mx*mx;
|
||||
mp = i;
|
||||
}
|
||||
}
|
||||
else {
|
||||
for (i = rshd.N; i < rshd.N+K; i++) {
|
||||
if (creal(cx[i]) > mx) { // imag(cx)=0
|
||||
mx = creal(cx[i]);
|
||||
mp = i;
|
||||
}
|
||||
}
|
||||
if (abs == 0) {
|
||||
// mx = 0;
|
||||
}
|
||||
if (mp == rshd.N || mp == rshd.N+K-1) return -4; // Randwert
|
||||
if (mp == rshd->L-1 || mp == K+rshd->L-1) return -4; // Randwert
|
||||
// mp == t mp == K+t
|
||||
|
||||
mpos = pos - ( rshd.N+K-1 - mp );
|
||||
mpos = pos - (K + rshd->L-1) + mp; // t = L-1
|
||||
|
||||
//xnorm = sqrt(qs[(mpos + 2*M) % M]);
|
||||
xnorm = 0.0;
|
||||
for (i = 0; i < rshd.N; i++) xnorm += bufs[(mpos-i + M) % M]*bufs[(mpos-i + M) % M];
|
||||
xnorm = 0.0; //xn[mp-t + i]
|
||||
for (i = 0; i < rshd->L; i++) xnorm += bufs[(mpos-i + M) % M]*bufs[(mpos-i + M) % M];
|
||||
xnorm = sqrt(xnorm);
|
||||
|
||||
mx /= xnorm*N_DFT;
|
||||
|
|
@ -409,7 +411,7 @@ static int f32buf_sample(FILE *fp, int inv) {
|
|||
return 0;
|
||||
}
|
||||
|
||||
static int read_bufbit(int symlen, char *bits, unsigned int mvp, int reset, float spb) {
|
||||
static int read_bufbit(int symlen, char *bits, unsigned int mvp, int reset, float dc, float spb) {
|
||||
// symlen==2: manchester2 0->10,1->01->1: 2.bit
|
||||
|
||||
static unsigned int rcount;
|
||||
|
|
@ -422,17 +424,19 @@ static int read_bufbit(int symlen, char *bits, unsigned int mvp, int reset, floa
|
|||
rbitgrenze = 0;
|
||||
}
|
||||
|
||||
// bei symlen=2 (Manchester) kein dc noetig,
|
||||
// allerdings M10-header mit symlen=1
|
||||
|
||||
rbitgrenze += spb;
|
||||
do {
|
||||
sum += bufs[(rcount + mvp + M) % M];
|
||||
sum += bufs[(rcount + mvp + M) % M] - dc;
|
||||
rcount++;
|
||||
} while (rcount < rbitgrenze); // n < spb
|
||||
|
||||
if (symlen == 2) {
|
||||
rbitgrenze += spb;
|
||||
do {
|
||||
sum -= bufs[(rcount + mvp + M) % M];
|
||||
sum -= bufs[(rcount + mvp + M) % M] - dc;
|
||||
rcount++;
|
||||
} while (rcount < rbitgrenze); // n < spb
|
||||
}
|
||||
|
|
@ -450,29 +454,38 @@ static int read_bufbit(int symlen, char *bits, unsigned int mvp, int reset, floa
|
|||
return 0;
|
||||
}
|
||||
|
||||
static int headcmp(int symlen, char *hdr, int len, unsigned int mvp, int inv, int option_dc, float spb) {
|
||||
static int headcmp(int symlen, unsigned int mvp, int inv, rsheader_t *rshd) {
|
||||
int errs = 0;
|
||||
int pos;
|
||||
int step = 1;
|
||||
char sign = 0;
|
||||
int len = 0;
|
||||
|
||||
float dc = 0.0;
|
||||
/*
|
||||
if (option_dc)
|
||||
{
|
||||
len = rshd->L;
|
||||
for (pos = 0; pos < len; pos++) {
|
||||
dc += bufs[(mvp - 1 - pos + M) % M];
|
||||
}
|
||||
dc /= (float)len;
|
||||
}
|
||||
*/
|
||||
if (symlen != 1) step = 2;
|
||||
if (inv) sign=1;
|
||||
|
||||
len = rshd->hLen;
|
||||
for (pos = 0; pos < len; pos += step) {
|
||||
read_bufbit(symlen, rawbits+pos, mvp+1-(int)(len*spb), pos==0, spb);
|
||||
read_bufbit(symlen, rawbits+pos, mvp+1-(int)(rshd->hLen*rshd->spb), pos==0, dc, rshd->spb);
|
||||
}
|
||||
rawbits[pos] = '\0';
|
||||
|
||||
while (len > 0) {
|
||||
if ((rawbits[len-1]^sign) != hdr[len-1]) errs += 1;
|
||||
if ((rawbits[len-1]^sign) != rshd->header[len-1]) errs += 1;
|
||||
len--;
|
||||
}
|
||||
|
||||
if (option_dc && errs < 3) {
|
||||
dc_ofs += dc;
|
||||
}
|
||||
|
||||
return errs;
|
||||
}
|
||||
|
||||
|
|
@ -510,7 +523,7 @@ static int init_buffers() {
|
|||
float normMatch;
|
||||
|
||||
int p2 = 1;
|
||||
int K, NN;
|
||||
int K, L;
|
||||
int n, k;
|
||||
float *match = NULL;
|
||||
float *m = NULL;
|
||||
|
|
@ -522,37 +535,36 @@ static int init_buffers() {
|
|||
float spb = 0.0;
|
||||
|
||||
int hLen = 0;
|
||||
int Lmax = 0;
|
||||
|
||||
for (j = 0; j < Nrs; j++) {
|
||||
rs_hdr[j].spb = sample_rate/(float)rs_hdr[j].bps;
|
||||
rs_hdr[j].hLen = strlen(rs_hdr[j].header);
|
||||
rs_hdr[j].N = rs_hdr[j].hLen * rs_hdr[j].spb + 0.5;
|
||||
rs_hdr[j].L = rs_hdr[j].hLen * rs_hdr[j].spb + 0.5;
|
||||
if (rs_hdr[j].hLen > hLen) hLen = rs_hdr[j].hLen;
|
||||
if (rs_hdr[j].L > Lmax) Lmax = rs_hdr[j].L;
|
||||
}
|
||||
|
||||
NN = hLen * sample_rate/2500.0 + 0.5; // max(hLen*spb)
|
||||
// L = hLen * sample_rate/2500.0 + 0.5; // max(hLen*spb)
|
||||
L = 2*Lmax;
|
||||
|
||||
M = 2*NN;
|
||||
M = 3*L;
|
||||
//if (samples_per_bit < 6) M = 6*N;
|
||||
|
||||
delay = NN/16;
|
||||
sample_in = 0;
|
||||
|
||||
p2 = 1;
|
||||
while (p2 < M) p2 <<= 1;
|
||||
while (p2 < 0x2000) p2 <<= 1; // or 0x4000, if sample not too short
|
||||
M = p2;
|
||||
N_DFT = p2;
|
||||
#ifdef ZEROPAD
|
||||
M -= 1;
|
||||
N_DFT <<= 1;
|
||||
#endif
|
||||
K = N_DFT - L;
|
||||
LOG2N = log(N_DFT)/log(2)+0.1; // 32bit cpu ... intermediate floating-point precision
|
||||
//while ((1 << LOG2N) < N_DFT) LOG2N++; // better N_DFT = (1 << LOG2N) ...
|
||||
|
||||
K = M-NN - delay; // N+K < M
|
||||
delay = L/16;
|
||||
M = N_DFT + delay + 8; // L+K < M
|
||||
|
||||
Nvar = NN; // wenn Nvar fuer xnorm, dann Nvar=rshd.N
|
||||
Nvar = Lmax; // wenn Nvar fuer xnorm, dann Nvar=rshd.L
|
||||
|
||||
rawbits = (char *)calloc( hLen+1, sizeof(char)); if (rawbits == NULL) return -100;
|
||||
bufs = (float *)calloc( M+1, sizeof(float)); if (bufs == NULL) return -100;
|
||||
|
|
@ -574,7 +586,7 @@ static int init_buffers() {
|
|||
ew[n] = cexp(-I*M_PI/(float)k);
|
||||
}
|
||||
|
||||
match = (float *)calloc( NN+1, sizeof(float)); if (match == NULL) return -1;
|
||||
match = (float *)calloc( L+1, sizeof(float)); if (match == NULL) return -1;
|
||||
m = (float *)calloc(N_DFT+1, sizeof(float)); if (m == NULL) return -1;
|
||||
|
||||
|
||||
|
|
@ -585,7 +597,7 @@ static int init_buffers() {
|
|||
spb = rs_hdr[j].spb;
|
||||
sigma = sqrt(log(2)) / (2*M_PI*rs_hdr[j].BT);
|
||||
|
||||
for (i = 0; i < rs_hdr[j].N; i++) {
|
||||
for (i = 0; i < rs_hdr[j].L; i++) {
|
||||
|
||||
pos = i/spb;
|
||||
t = (i - pos*spb)/spb - 0.5;
|
||||
|
|
@ -606,12 +618,12 @@ static int init_buffers() {
|
|||
match[i] = b;
|
||||
}
|
||||
|
||||
normMatch = sqrt(norm2_match(match, rs_hdr[j].N));
|
||||
for (i = 0; i < rs_hdr[j].N; i++) {
|
||||
normMatch = sqrt(norm2_match(match, rs_hdr[j].L));
|
||||
for (i = 0; i < rs_hdr[j].L; i++) {
|
||||
match[i] /= normMatch;
|
||||
}
|
||||
|
||||
for (i = 0; i < rs_hdr[j].N; i++) m[rs_hdr[j].N-1 - i] = match[i];
|
||||
for (i = 0; i < rs_hdr[j].L; i++) m[rs_hdr[j].L-1 - i] = match[i]; // t = L-1
|
||||
while (i < N_DFT) m[i++] = 0.0;
|
||||
dft(m, rs_hdr[j].Fm);
|
||||
|
||||
|
|
@ -752,7 +764,7 @@ int main(int argc, char **argv) {
|
|||
if ( strncmp(rs_hdr[j].type, "C34C50", 6) == 0 ) continue;
|
||||
#endif
|
||||
mv0_pos[j] = mv_pos[j];
|
||||
mp[j] = getCorrDFT(-1, K, 0, mv+j, mv_pos+j, rs_hdr[j]);
|
||||
mp[j] = getCorrDFT(-1, K, 0, mv+j, mv_pos+j, rs_hdr+j);
|
||||
}
|
||||
k = 0;
|
||||
}
|
||||
|
|
@ -767,8 +779,8 @@ int main(int argc, char **argv) {
|
|||
if (mp[j] > 0 && (mv[j] > rs_hdr[j].thres || mv[j] < -rs_hdr[j].thres)) {
|
||||
if (mv_pos[j] > mv0_pos[j]) {
|
||||
|
||||
herrs = headcmp(1, rs_hdr[j].header, rs_hdr[j].hLen, mv_pos[j], mv[j]<0, 0, rs_hdr[j].spb);
|
||||
if (herrs < 2) { // max 1 bitfehler in header
|
||||
herrs = headcmp(1, mv_pos[j], mv[j]<0, rs_hdr+j);
|
||||
if (herrs < rs_hdr[j].herrs) { // max bit-errors in header
|
||||
|
||||
if ( strncmp(rs_hdr[j].type, "IMET", 4) == 0 )
|
||||
{
|
||||
|
|
@ -835,7 +847,7 @@ int main(int argc, char **argv) {
|
|||
|
||||
if (k >= K-4) {
|
||||
mv0_pos[j] = mv_pos[j];
|
||||
mp[j] = getCorrDFT(-1, K, 0, mv+j, mv_pos+j, rs_hdr[j]);
|
||||
mp[j] = getCorrDFT(-1, K, 0, mv+j, mv_pos+j, rs_hdr+j);
|
||||
k = 0;
|
||||
}
|
||||
else {
|
||||
|
|
@ -852,7 +864,9 @@ int main(int argc, char **argv) {
|
|||
}
|
||||
}
|
||||
}
|
||||
else header_found = 1;
|
||||
else {
|
||||
header_found = 1;
|
||||
}
|
||||
|
||||
if (header_found) {
|
||||
if (!option_silent) {
|
||||
|
|
|
|||
Ładowanie…
Reference in New Issue