kopia lustrzana https://github.com/rs1729/RS
IQ-baseband: rotate and decimate
Zilog80
rodzic
648bc23c99
commit
bbae81cc94
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@ -265,7 +265,7 @@ float read_wav_header(pcm_t *pcm, FILE *fp) {
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fprintf(stderr, "channels : %d\n", channels);
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if (pcm->sel_ch < 0 || pcm->sel_ch >= channels) pcm->sel_ch = 0; // default channel: 0
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fprintf(stderr, "channel-In : %d\n", pcm->sel_ch+1);
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//fprintf(stderr, "channel-In : %d\n", pcm->sel_ch+1); // nur wenn nicht IQ
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if ((bits_sample != 8) && (bits_sample != 16)) return -1;
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@ -277,6 +277,7 @@ float read_wav_header(pcm_t *pcm, FILE *fp) {
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return 0;
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}
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static int f32read_sample(dsp_t *dsp, float *s) {
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int i;
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short b = 0;
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@ -313,6 +314,29 @@ static int f32read_csample(dsp_t *dsp, float complex *z) {
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return 0;
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}
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static int f32read_cblock(dsp_t *dsp) {
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int n;
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int len;
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int sum;
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len = dsp->decM;
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if (dsp->bps == 8) {
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ui8_t u[2*dsp->decM];
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len = fread( u, dsp->bps/8, 2*dsp->decM, dsp->fp) / 2;
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for (n = 0; n < len; n++) dsp->decMbuf[n] = (u[2*n]-128)/128.0 + I*(u[2*n+1]-128)/128.0;
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}
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else { // dsp->bps == 16
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short b[2*dsp->decM];
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len = fread( b, dsp->bps/8, 2*dsp->decM, dsp->fp) / 2;
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for (n = 0; n < len; n++) dsp->decMbuf[n] = b[2*n]/32768.0 + I*b[2*n+1]/32768.0;
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}
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return len;
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}
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float get_bufvar(dsp_t *dsp, int ofs) {
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float mu = dsp->xs[(dsp->sample_out+dsp->M + ofs) % dsp->M]/dsp->Nvar;
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float var = dsp->qs[(dsp->sample_out+dsp->M + ofs) % dsp->M]/dsp->Nvar - mu*mu;
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@ -357,6 +381,55 @@ static int get_SNR(dsp_t *dsp) {
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return 0;
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}
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static int res = 1; // 1..10 Hz, exp_lut resolution
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static double *ws_dec;
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static double sinc(double x) {
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double y;
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if (x == 0) y = 1;
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else y = sin(M_PI*x)/(M_PI*x);
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return y;
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}
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static int decimate_init(int taps, float f) {
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double *h, *w;
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double norm = 0;
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int n;
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if (taps % 2 == 0) taps++; // odd/symmetric
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if ( taps < 1 ) taps = 1;
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h = (double*)calloc( taps+1, sizeof(double));
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w = (double*)calloc( taps+1, sizeof(double));
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ws_dec = (double*)calloc( taps+1, sizeof(double));
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for (n = 0; n < taps; n++) {
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w[n] = 7938/18608.0 - 9240/18608.0*cos(2*M_PI*n/(taps-1)) + 1430/18608.0*cos(4*M_PI*n/(taps-1)); // Blackmann
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h[n] = 2*f*sinc(2*f*(n-(taps-1)/2));
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ws_dec[n] = w[n]*h[n];
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norm += ws_dec[n];
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}
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for (n = 0; n < taps; n++) {
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ws_dec[n] /= norm;
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}
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free(h); h = NULL;
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free(w); w = NULL;
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return taps;
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}
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static float complex lowpass(float complex buffer[], int sample, int M) {
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int n;
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double complex w = 0;
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for (n = 0; n < M; n++) {
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w += buffer[(sample+n+1)%M]*ws_dec[M-1-n];
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}
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return (float complex)w;
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}
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int f32buf_sample(dsp_t *dsp, int inv) {
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float s = 0.0;
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float xneu, xalt;
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@ -368,10 +441,20 @@ int f32buf_sample(dsp_t *dsp, int inv) {
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if (dsp->opt_iq) {
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if ( f32read_csample(dsp, &z) == EOF ) return EOF;
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if (dsp->opt_iq == 5) {
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int j;
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if ( f32read_cblock(dsp) < dsp->decM ) return EOF;
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for (j = 0; j < dsp->decM; j++) {
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dsp->decXbuffer[dsp->sample_dec % dsp->dectaps] = dsp->decMbuf[j] * dsp->ex[dsp->sample_dec % (dsp->sr_base/res)];
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dsp->sample_dec += 1;
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}
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z = lowpass(dsp->decXbuffer, dsp->sample_dec, dsp->dectaps);
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}
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else if ( f32read_csample(dsp, &z) == EOF ) return EOF;
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dsp->raw_iqbuf[dsp->sample_in % dsp->N_IQBUF] = z;
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z *= cexp(-t*2*M_PI*dsp->df*I);
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//z *= cexp(-t*2*M_PI*dsp->df*I);
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z0 = dsp->rot_iqbuf[(dsp->sample_in-1 + dsp->N_IQBUF) % dsp->N_IQBUF];
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w = z * conj(z0);
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s = gain * carg(w)/M_PI;
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@ -672,6 +755,49 @@ int init_buffers(dsp_t *dsp) {
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float *m = NULL;
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if (dsp->opt_iq == 5)
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{
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int dec_sr = 48000;
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int decM = 1;
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int sr_base = dsp->sr;
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if (dec_sr > sr_base) dec_sr = sr_base;
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if (dec_sr < sr_base) {
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while (sr_base % dec_sr) dec_sr += 1;
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decM = sr_base / dec_sr;
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}
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int IF = dsp->sr/decM; fprintf(stderr, "IF: %d\n", IF);
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float f_lp = (IF+20e3)/(4.0*sr_base);
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float t_bw = (IF-20e3)/*2.0*/; if (t_bw < 0) t_bw = 8e3;
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int taps = 4*sr_base/t_bw; if (taps%2==0) taps++; // 4/0.01+1=401
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dsp->dectaps = decimate_init(taps, f_lp);
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dsp->sr_base = sr_base;
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dsp->sr = IF; // dsp->sr/decM
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dsp->sps /= (float)decM;
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dsp->_spb /= (float)decM;
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dsp->decM = decM; fprintf(stderr, "dec: %d\n", decM);
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}
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if (dsp->opt_iq == 5)
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{
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dsp->decXbuffer = calloc( dsp->dectaps+1, sizeof(float complex));
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if (dsp->decXbuffer == NULL) return -1;
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dsp->decMbuf = calloc( dsp->decM+1, sizeof(float complex));
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if (dsp->decMbuf == NULL) return -1;
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dsp->ex = calloc(dsp->sr_base/res+1, sizeof(float complex));
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if (dsp->ex == NULL) return -1;
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for (n = 0; n < dsp->sr_base/res; n++) {
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t = (double)n*dsp->xlt_fq; // xlt_fq=xltFq/sample_rate , integer xltFq frequency
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dsp->ex[n] = cexp(t*2*M_PI*I);
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}
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}
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L = dsp->hdrlen * dsp->sps + 0.5;
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M = 3*L;
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//if (dsp->sps < 6) M = 6*L;
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@ -800,8 +926,17 @@ int free_buffers(dsp_t *dsp) {
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if (dsp->opt_iq)
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{
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if (dsp->raw_iqbuf) { free(dsp->raw_iqbuf); dsp->raw_iqbuf = NULL; }
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if (dsp->rot_iqbuf) { free(dsp->rot_iqbuf); dsp->rot_iqbuf = NULL; }
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if (dsp->raw_iqbuf) { free(dsp->raw_iqbuf); dsp->raw_iqbuf = NULL; }
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if (dsp->rot_iqbuf) { free(dsp->rot_iqbuf); dsp->rot_iqbuf = NULL; }
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}
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if (dsp->opt_iq == 5)
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{
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if (dsp->decXbuffer) { free(dsp->decXbuffer); dsp->decXbuffer = NULL; }
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if (dsp->decMbuf) { free(dsp->decMbuf); dsp->decMbuf = NULL; }
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if (dsp->ex) { free(dsp->ex); dsp->ex = NULL; }
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if (ws_dec) { free(ws_dec); ws_dec = NULL; }
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}
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return 0;
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@ -92,6 +92,15 @@ typedef struct {
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double V_signal;
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double SNRdB;
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int sr_base;
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int decM;
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int dectaps;
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float complex *decXbuffer;
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float complex *decMbuf;
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float complex *ex; // exp_lut
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ui32_t sample_dec;
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double xlt_fq;
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} dsp_t;
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@ -940,6 +940,16 @@ int main(int argc, char **argv) {
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else if (strcmp(*argv, "--iq0") == 0) { option_iq = 1; } // differential/FM-demod
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else if (strcmp(*argv, "--iq2") == 0) { option_iq = 2; }
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else if (strcmp(*argv, "--iq3") == 0) { option_iq = 3; } // iq2==iq3
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else if (strcmp(*argv, "--IQ") == 0) { // baseband -> IF (rotate and decimate)
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double fq = 0.0; // --IQ <fq> , -0.5 < fq < 0.5
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++argv;
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if (*argv) fq = atof(*argv);
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else return -1;
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if (fq < -0.5) fq = -0.5;
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if (fq > 0.5) fq = 0.5;
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dsp.xlt_fq = fq;
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option_iq = 5;
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}
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else if (strcmp(*argv, "--dbg") == 0) { gpx.option.dbg = 1; }
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else {
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fp = fopen(*argv, "rb");
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@ -1634,6 +1634,16 @@ int main(int argc, char *argv[]) {
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else if (strcmp(*argv, "--iq0") == 0) { option_iq = 1; } // differential/FM-demod
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else if (strcmp(*argv, "--iq2") == 0) { option_iq = 2; }
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else if (strcmp(*argv, "--iq3") == 0) { option_iq = 3; } // iq2==iq3
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else if (strcmp(*argv, "--IQ") == 0) { // baseband -> IF (rotate and decimate)
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double fq = 0.0; // --IQ <fq> , -0.5 < fq < 0.5
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++argv;
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if (*argv) fq = atof(*argv);
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else return -1;
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if (fq < -0.5) fq = -0.5;
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if (fq > 0.5) fq = 0.5;
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dsp.xlt_fq = fq;
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option_iq = 5;
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}
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else if (strcmp(*argv, "--ofs") == 0) { option_ofs = 1; }
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else if (strcmp(*argv, "--rawhex") == 0) { rawhex = 2; } // raw hex input
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else if (strcmp(*argv, "--xorhex") == 0) { rawhex = 2; xorhex = 1; } // raw xor input
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