* Normalize a complex number's magnitude to 1
*/
static inline COMP comp_normalize(COMP a){
- COMP b;
- float av = sqrtf((a.real*a.real)+(a.imag*a.imag));
- b.real = a.real/av;
- b.imag = a.imag/av;
- return b;
+ COMP b;
+ float av = sqrtf((a.real*a.real)+(a.imag*a.imag));
+ b.real = a.real/av;
+ b.imag = a.imag/av;
+ return b;
}
fsk->est_space = Rs-(Rs/5);
/* Set up rx state */
- fsk->phi1_c = comp_exp_j(0);
- fsk->phi2_c = comp_exp_j(0);
- fsk->phi3_c = comp_exp_j(0);
- fsk->phi4_c = comp_exp_j(0);
- fsk->phi1_c.real = 0;
- fsk->phi1_c.imag = 1;
+ for( i=0; i<M; i++)
+ fsk->phi_c[i] = comp_exp_j(0);
memold = (4*fsk->Ts);
/* Set up demod stats */
fsk->EbNodB = 0;
- fsk->f1_est = 0;
- fsk->f2_est = 0;
- fsk->f3_est = 0;
- fsk->f4_est = 0;
+
+ for( i=0; i<M; i++)
+ fsk->f_est[i] = 0;
+
fsk->ppm = 0;
fsk->stats = NULL;
fsk->est_space = HORUS_MIN_SPACING;
/* Set up rx state */
- fsk->phi1_c = comp_exp_j(0);
- fsk->phi2_c = comp_exp_j(0);
- fsk->phi3_c = comp_exp_j(0);
- fsk->phi4_c = comp_exp_j(0);
-
- fsk->phi1_c.real = 0;
- fsk->phi1_c.imag = 1;
+ for( i=0; i<M; i++)
+ fsk->phi_c[i] = comp_exp_j(0);
memold = (4*fsk->Ts);
/* Set up demod stats */
fsk->EbNodB = 0;
- fsk->f1_est = 0;
- fsk->f2_est = 0;
- fsk->f3_est = 0;
- fsk->f4_est = 0;
+
+ for( i=0; i<M; i++)
+ fsk->f_est[i] = 0;
+
fsk->ppm = 0;
fsk->stats = NULL;
*/
void fsk_set_est_limits(struct FSK *fsk,int est_min, int est_max){
- fsk->est_min = est_min;
+ fsk->est_min = est_min;
if(fsk->est_min<0) fsk->est_min = 0;
fsk->est_max = est_max;
int Ndft = fsk->Ndft;
int Fs = fsk->Fs;
int nin = fsk->nin;
- int i,j;
+ size_t i,j;
int fft_samps;
float hann;
float max;
kiss_fft_cfg fft_cfg = fsk->fft_cfg;
int freqi[M];
int f_min,f_max,f_zero;
- /* Array to do complex FFT from using kiss_fft */
+ /* Array to do complex FFT from using kiss_fft */
#ifdef DEMOD_ALLOC_STACK
kiss_fft_cpx *fftin = (kiss_fft_cpx*)alloca(sizeof(kiss_fft_cpx)*Ndft);
kiss_fft_cpx *fftout = (kiss_fft_cpx*)alloca(sizeof(kiss_fft_cpx)*Ndft);
int fft_loops = nin/Ndft;
for(j=0; j<fft_loops; j++){
/* Copy FSK buffer into reals of FFT buffer and apply a hann window */
- for(i=0; i<fft_samps; i++){
- hann = 1-cosf((2*M_PI*(float)(i))/((float)fft_samps-1));
-
- fftin[i].r = 0.5*hann*fsk_in[i+Ndft*j].real;
- fftin[i].i = 0.5*hann*fsk_in[i+Ndft*j].imag;
- }
- /* Zero out the remaining slots */
- for(; i<Ndft;i++){
- fftin[i].r = 0;
- fftin[i].i = 0;
- }
-
- /* Do the FFT */
- kiss_fft(fft_cfg,fftin,fftout);
-
- /* Find the magnitude^2 of each freq slot and stash away in the real
- * value, so this only has to be done once. Since we're only comparing
- * these values and only need the mag of 2 points, we don't need to do
- * a sqrt to each value */
- for(i=0; i<Ndft/2; i++){
- fftout[i].r = (fftout[i].r*fftout[i].r) + (fftout[i].i*fftout[i].i) ;
- }
-
- /* Zero out the minimum and maximum ends */
- for(i=0; i<f_min; i++){
- fftout[i].r = 0;
- }
- for(i=f_max-1; i<Ndft/2; i++){
- fftout[i].r = 0;
- }
- /* Mix back in with the previous fft block */
- /* Copy new fft est into imag of fftout for frequency divination below */
- for(i=0; i<Ndft/2; i++){
- fsk->fft_est[i] = (fsk->fft_est[i]*(1-tc)) + (sqrtf(fftout[i].r)*tc);
- fftout[i].i = fsk->fft_est[i];
- }
- }
-
+ for(i=0; i<fft_samps; i++){
+ hann = 1-cosf((2*M_PI*(float)(i))/((float)fft_samps-1));
+ fftin[i].r = 0.5*hann*fsk_in[i+Ndft*j].real;
+ fftin[i].i = 0.5*hann*fsk_in[i+Ndft*j].imag;
+ }
+ /* Zero out the remaining slots */
+ for(; i<Ndft;i++){
+ fftin[i].r = 0;
+ fftin[i].i = 0;
+ }
+
+ /* Do the FFT */
+ kiss_fft(fft_cfg,fftin,fftout);
+
+ /* Find the magnitude^2 of each freq slot and stash away in the real
+ * value, so this only has to be done once. Since we're only comparing
+ * these values and only need the mag of 2 points, we don't need to do
+ * a sqrt to each value */
+ for(i=0; i<Ndft/2; i++){
+ fftout[i].r = (fftout[i].r*fftout[i].r) + (fftout[i].i*fftout[i].i) ;
+ }
+
+ /* Zero out the minimum and maximum ends */
+ for(i=0; i<f_min; i++){
+ fftout[i].r = 0;
+ }
+ for(i=f_max-1; i<Ndft/2; i++){
+ fftout[i].r = 0;
+ }
+ /* Mix back in with the previous fft block */
+ /* Copy new fft est into imag of fftout for frequency divination below */
+ for(i=0; i<Ndft/2; i++){
+ fsk->fft_est[i] = (fsk->fft_est[i]*(1-tc)) + (sqrtf(fftout[i].r)*tc);
+ fftout[i].i = fsk->fft_est[i];
+ }
+ }
+
modem_probe_samp_f("t_fft_est",fsk->fft_est,Ndft/2);
max = 0;
/* Find the M frequency peaks here */
for(i=0; i<M; i++){
- imax = 0;
- max = 0;
- for(j=0;j<Ndft/2;j++){
- if(fftout[j].i > max){
- max = fftout[j].i;
- imax = j;
- }
- }
- /* Blank out FMax +/-Fspace/2 */
- f_min = imax - f_zero;
- f_min = f_min < 0 ? 0 : f_min;
- f_max = imax + f_zero;
- f_max = f_max > Ndft ? Ndft : f_max;
- for(j=f_min; j<f_max; j++)
- fftout[j].i = 0;
-
- /* Stick the freq index on the list */
- freqi[i] = imax;
- }
-
- /* Gnome sort the freq list */
- /* My favorite sort of sort*/
- i = 1;
- while(i<M){
- if(freqi[i] >= freqi[i-1]) i++;
- else{
- j = freqi[i];
- freqi[i] = freqi[i-1];
- freqi[i-1] = j;
- if(i>1) i--;
- }
- }
-
- /* Convert freqs from indices to frequencies */
- for(i=0; i<M; i++){
- freqs[i] = (float)(freqi[i])*((float)Fs/(float)Ndft);
- }
+ imax = 0;
+ max = 0;
+ for(j=0;j<Ndft/2;j++){
+ if(fftout[j].i > max){
+ max = fftout[j].i;
+ imax = j;
+ }
+ }
+ /* Blank out FMax +/-Fspace/2 */
+ f_min = imax - f_zero;
+ f_min = f_min < 0 ? 0 : f_min;
+ f_max = imax + f_zero;
+ f_max = f_max > Ndft ? Ndft : f_max;
+ for(j=f_min; j<f_max; j++)
+ fftout[j].i = 0;
+
+ /* Stick the freq index on the list */
+ freqi[i] = imax;
+ }
+
+ /* Gnome sort the freq list */
+ /* My favorite sort of sort*/
+ i = 1;
+ while(i<M){
+ if(freqi[i] >= freqi[i-1]) i++;
+ else{
+ j = freqi[i];
+ freqi[i] = freqi[i-1];
+ freqi[i-1] = j;
+ if(i>1) i--;
+ }
+ }
+
+ /* Convert freqs from indices to frequencies */
+ for(i=0; i<M; i++){
+ freqs[i] = (float)(freqi[i])*((float)Fs/(float)Ndft);
+ }
#ifndef DEMOD_ALLOC_STACK
free(fftin);
free(fftout);
int P = fsk->P;
int Nmem = fsk->Nmem;
int M = fsk->mode;
- int i,j,dc_i,cbuf_i;
+ size_t i,j,m,dc_i,cbuf_i;
float ft1;
int nstash = fsk->nstash;
- COMP *f1_int, *f2_int;
-
- COMP t1,t2;
- COMP phi1_c = fsk->phi1_c;
- COMP phi2_c = fsk->phi2_c;
- COMP phi_ft;
+ COMP* f_int[M]; /* Filtered and downsampled symbol tones */
+ COMP t[M]; /* complex number temps */
+ COMP t_c; /* another complex temp */
+ COMP phi_c[M];
+ COMP phi_ft;
int nold = Nmem-nin;
- COMP dphi1,dphi2;
+
+ COMP dphi[M];
COMP dphift;
float rx_timing,norm_rx_timing,old_norm_rx_timing,d_norm_rx_timing,appm;
int using_old_samps;
- COMP *sample_src;
-
- COMP *f1_intbuf,*f2_intbuf;
+
+ COMP* sample_src;
+ COMP* f_intbuf_m;
float f_est[M],fc_avg,fc_tx;
float meanebno,stdebno,eye_max;
int neyesamp,neyeoffset;
+ #ifdef MODEMPROBE_ENABLE
+ char mp_name_tmp[20]; /* Temporary string for modem probe trace names */
+ #endif
+
+ /* Load up demod phases from struct */
+ for( m=0; m<M; m++)
+ phi_c[m] = fsk->phi_c[m];
+
/* Estimate tone frequencies */
fsk_demod_freq_est(fsk,fsk_in,f_est,M);
modem_probe_samp_f("t_f_est",f_est,M);
- /* allocate memory for the integrated samples */
- #ifdef DEMOD_ALLOC_STACK
- /* allocate memory for the integrated samples */
- /* Note: This must be kept after fsk_demod_freq_est for memory usage reasons */
- f1_int = (COMP*) alloca(sizeof(COMP)*(nsym+1)*P);
- f2_int = (COMP*) alloca(sizeof(COMP)*(nsym+1)*P);
- /* Allocate circular buffers for integration */
- f1_intbuf = (COMP*) alloca(sizeof(COMP)*Ts);
- f2_intbuf = (COMP*) alloca(sizeof(COMP)*Ts);
+ /* Allocate circular buffer for integration */
+ #ifdef DEMOD_ALLOC_STACK
+ f_intbuf_m = (COMP*) alloca(sizeof(COMP)*Ts);
#else
- f1_int = (COMP*) malloc(sizeof(COMP)*(nsym+1)*P);
- f2_int = (COMP*) malloc(sizeof(COMP)*(nsym+1)*P);
-
- f1_intbuf = (COMP*) malloc(sizeof(COMP)*Ts);
- f2_intbuf = (COMP*) malloc(sizeof(COMP)*Ts);
+ f_intbuf_m = (COMP*) malloc(sizeof(COMP)*Ts);
#endif
+ /* allocate memory for the integrated samples */
+ for( m=0; m<M; m++){
+ #ifdef DEMOD_ALLOC_STACK
+ /* allocate memory for the integrated samples */
+ /* Note: This must be kept after fsk_demod_freq_est for memory usage reasons */
+ f_int[m] = (COMP*) alloca(sizeof(COMP)*(nsym+1)*P);
+
+ #else
+ f_int[m] = (COMP*) malloc(sizeof(COMP)*(nsym+1)*P);
+ #endif
+ }
+
/* If this is the first run, we won't have any valid f_est */
- if(fsk->f1_est<1){
- fsk->f1_est = f_est[0];
- fsk->f2_est = f_est[1];
- }
-
- /* Back the stored phase off to account for re-integraton of old samples */
- dphi1 = comp_exp_j(-2*(Nmem-nin-(Ts/P))*M_PI*((fsk->f1_est)/(float)(Fs)));
- dphi2 = comp_exp_j(-2*(Nmem-nin-(Ts/P))*M_PI*((fsk->f2_est)/(float)(Fs)));
-
- phi1_c = cmult(dphi1,phi1_c);
- phi2_c = cmult(dphi2,phi2_c);
-
- /* Figure out how much to nudge each sample downmixer for every sample */
- dphi1 = comp_exp_j(2*M_PI*((fsk->f1_est)/(float)(Fs)));
- dphi2 = comp_exp_j(2*M_PI*((fsk->f2_est)/(float)(Fs)));
-
- dc_i = 0;
- cbuf_i = 0;
- sample_src = &(fsk->samp_old[nstash-nold]);
- using_old_samps = 1;
- /* Pre-fill integration buffer */
- for(dc_i=0; dc_i<Ts-(Ts/P); dc_i++){
- /* Switch sample source to new samples when we run out of old ones */
- if(dc_i>=nold && using_old_samps){
- sample_src = &fsk_in[0];
- dc_i = 0;
- using_old_samps = 0;
-
- /* Recalculate delta-phi after switching to new sample source */
- phi1_c = comp_normalize(phi1_c);
- phi2_c = comp_normalize(phi2_c);
- dphi1 = comp_exp_j(2*M_PI*(f_est[0]/(float)(Fs)));
- dphi2 = comp_exp_j(2*M_PI*(f_est[1]/(float)(Fs)));
- }
- /* Downconvert and place into integration buffer */
- f1_intbuf[dc_i]=cmult(sample_src[dc_i],cconj(phi1_c));
- f2_intbuf[dc_i]=cmult(sample_src[dc_i],cconj(phi2_c));
-
- modem_probe_samp_c("t_f1_dc",&f1_intbuf[dc_i],1);
- modem_probe_samp_c("t_f2_dc",&f2_intbuf[dc_i],1);
- /* Spin downconversion phases */
- phi1_c = cmult(phi1_c,dphi1);
- phi2_c = cmult(phi2_c,dphi2);
+ /* TODO: add first_run flag to FSK to make negative freqs possible */
+ if(fsk->f_est[0]<1){
+ for( m=0; m<M; m++)
+ fsk->f_est[m] = f_est[m];
}
- cbuf_i = dc_i;
- /* Integrate over Ts at offsets of Ts/P */
- for(i=0; i<(nsym+1)*P; i++){
- /* Downconvert and Place Ts/P samples in the integration buffers */
- for(j=0; j<(Ts/P); j++,dc_i++){
+ /* Initalize downmixers for each symbol tone */
+ for( m=0; m<M; m++){
+ /* Back the stored phase off to account for re-integraton of old samples */
+ dphi[m] = comp_exp_j(-2*(Nmem-nin-(Ts/P))*M_PI*((fsk->f_est[m])/(float)(Fs)));
+ phi_c[m] = cmult(dphi[m],phi_c[m]);
+
+ /* Figure out how much to nudge each sample downmixer for every sample */
+ dphi[m] = comp_exp_j(2*M_PI*((fsk->f_est[m])/(float)(Fs)));
+ }
+
+ /* Integrate and downsample for symbol tones */
+ for(m=0; m<M; m++){
+ /* Copy buffer pointers in to avoid second buffer indirection */
+ float f_est_m = f_est[m];
+ COMP* f_int_m = &(f_int[m][0]);
+ COMP dphi_m = dphi[m];
+
+ dc_i = 0;
+ cbuf_i = 0;
+ sample_src = &(fsk->samp_old[nstash-nold]);
+ using_old_samps = 1;
+
+ /* Pre-fill integration buffer */
+ for(dc_i=0; dc_i<Ts-(Ts/P); dc_i++){
/* Switch sample source to new samples when we run out of old ones */
if(dc_i>=nold && using_old_samps){
sample_src = &fsk_in[0];
dc_i = 0;
using_old_samps = 0;
- /* Recalculate delta-phi after switching to new sample source */
- phi1_c = comp_normalize(phi1_c);
- phi2_c = comp_normalize(phi2_c);
- dphi1 = comp_exp_j(2*M_PI*((f_est[0])/(float)(Fs)));
- dphi2 = comp_exp_j(2*M_PI*((f_est[1])/(float)(Fs)));
+ /* Recalculate delta-phi after switching to new sample source */
+ phi_c[m] = comp_normalize(phi_c[m]);
+ dphi_m = comp_exp_j(2*M_PI*((f_est_m)/(float)(Fs)));
}
/* Downconvert and place into integration buffer */
- f1_intbuf[cbuf_i+j]=cmult(sample_src[dc_i],cconj(phi1_c));
- f2_intbuf[cbuf_i+j]=cmult(sample_src[dc_i],cconj(phi2_c));
-
- modem_probe_samp_c("t_f1_dc",&f1_intbuf[cbuf_i+j],1);
- modem_probe_samp_c("t_f2_dc",&f2_intbuf[cbuf_i+j],1);
- /* Spin downconversion phases */
- phi1_c = cmult(phi1_c,dphi1);
- phi2_c = cmult(phi2_c,dphi2);
+ f_intbuf_m[dc_i]=cmult(sample_src[dc_i],cconj(phi_c[m]));
+ #ifdef MODEMPROBE_ENABLE
+ snprintf(mp_name_tmp,19,"t_f%zd_dc",m+1);
+ modem_probe_samp_c(mp_name_tmp,&f_intbuf_m[dc_i],1);
+ #endif
+ /* Spin downconversion phases */
+ phi_c[m] = cmult(phi_c[m],dphi_m);
}
-
- /* Dump internal samples */
-
- cbuf_i += Ts/P;
- if(cbuf_i>=Ts) cbuf_i = 0;
-
- /* Integrate over the integration buffers, save samples */
- t1 = t2 = comp0();
- for(j=0; j<Ts; j++){
- t1 = cadd(t1,f1_intbuf[j]);
- t2 = cadd(t2,f2_intbuf[j]);
+ cbuf_i = dc_i;
+
+ /* Integrate over Ts at offsets of Ts/P */
+ for(i=0; i<(nsym+1)*P; i++){
+ /* Downconvert and Place Ts/P samples in the integration buffers */
+ for(j=0; j<(Ts/P); j++,dc_i++){
+ /* Switch sample source to new samples when we run out of old ones */
+ if(dc_i>=nold && using_old_samps){
+ sample_src = &fsk_in[0];
+ dc_i = 0;
+ using_old_samps = 0;
+
+ /* Recalculate delta-phi after switching to new sample source */
+ phi_c[m] = comp_normalize(phi_c[m]);
+ dphi_m = comp_exp_j(2*M_PI*((f_est_m)/(float)(Fs)));
+ }
+ /* Downconvert and place into integration buffer */
+ f_intbuf_m[cbuf_i+j]=cmult(sample_src[dc_i],cconj(phi_c[m]));
+
+ #ifdef MODEMPROBE_ENABLE
+ snprintf(mp_name_tmp,19,"t_f%zd_dc",m+1);
+ modem_probe_samp_c(mp_name_tmp,&f_intbuf_m[cbuf_i+j],1);
+ #endif
+ /* Spin downconversion phases */
+ phi_c[m] = cmult(phi_c[m],dphi_m);
+
+ }
+
+ /* Dump internal samples */
+ cbuf_i += Ts/P;
+ if(cbuf_i>=Ts) cbuf_i = 0;
+
+ /* Integrate over the integration buffers, save samples */
+ float it_r = 0;
+ float it_i = 0;
+ for(j=0; j<Ts; j++){
+ it_r += f_intbuf_m[j].real;
+ it_i += f_intbuf_m[j].imag;
+ }
+ f_int_m[i].real = it_r;
+ f_int_m[i].imag = it_i;
}
- f1_int[i] = t1;
- f2_int[i] = t2;
-
}
- fsk->phi1_c = phi1_c;
- fsk->phi2_c = phi2_c;
-
- fsk->f1_est = f_est[0];
- fsk->f2_est = f_est[1];
+ /* Save phases back into FSK struct */
+ for(m=0; m<M; m++){
+ fsk->phi_c[m] = phi_c[m];
+ fsk->f_est[m] = f_est[m];
+ }
/* Stash samples away in the old sample buffer for the next round of bit getting */
memcpy((void*)&(fsk->samp_old[0]),(void*)&(fsk_in[nin-nstash]),sizeof(COMP)*nstash);
dphift = comp_exp_j(2*M_PI*((float)(Rs)/(float)(P*Rs)));
phi_ft.real = 1;
phi_ft.imag = 0;
- t1=comp0();
+ t_c=comp0();
for(i=0; i<(nsym+1)*P; i++){
/* Get abs^2 of fx_int[i], and add 'em */
- ft1 = (f1_int[i].real*f1_int[i].real) + (f1_int[i].imag*f1_int[i].imag);
- ft1 += (f2_int[i].real*f2_int[i].real) + (f2_int[i].imag*f2_int[i].imag);
+ ft1 = 0;
+ for( m=0; m<M; m++){
+ ft1 += (f_int[m][i].real*f_int[m][i].real) + (f_int[m][i].imag*f_int[m][i].imag);
+ }
/* Down shift and accumulate magic line */
- t1 = cadd(t1,fcmult(ft1,phi_ft));
+ t_c = cadd(t_c,fcmult(ft1,phi_ft));
/* Spin the oscillator for the magic line shift */
phi_ft = cmult(phi_ft,dphift);
}
/* Get the magic angle */
- norm_rx_timing = atan2f(t1.imag,t1.real)/(2*M_PI);
+ norm_rx_timing = atan2f(t_c.imag,t_c.real)/(2*M_PI);
rx_timing = norm_rx_timing*(float)P;
old_norm_rx_timing = fsk->norm_rx_timing;
}
/* Figure out how many samples are needed the next modem cycle */
- if(norm_rx_timing > 0.25){
+ if(norm_rx_timing > 0.25)
fsk->nin = N+Ts/2;
- }
- else if(norm_rx_timing < -0.25){
+ else if(norm_rx_timing < -0.25)
fsk->nin = N-Ts/2;
- }
else
fsk->nin = N;
float fract = rx_timing - (float)low_sample;
int high_sample = (int)ceilf(rx_timing);
- /* Vars for finding the max-of-4 for each bit */
- float tmax[2];
+ /* Vars for finding the max-of-4 for each bit */
+ float tmax[M];
#ifdef EST_EBNO
meanebno = 0;
/* also, resample fx_int */
for(i=0; i<nsym; i++){
int st = (i+1)*P;
- t1 = fcmult(1-fract,f1_int[st+ low_sample]);
- t1 = cadd(t1,fcmult( fract,f1_int[st+high_sample]));
- t2 = fcmult(1-fract,f2_int[st+ low_sample]);
- t2 = cadd(t2,fcmult( fract,f2_int[st+high_sample]));
+ for( m=0; m<M; m++){
+ t[m] = fcmult(1-fract,f_int[m][st+ low_sample]);
+ t[m] = cadd(t[m],fcmult( fract,f_int[m][st+high_sample]));
+ /* Figure mag^2 of each resampled fx_int */
+ tmax[m] = (t[m].real*t[m].real) + (t[m].imag*t[m].imag);
+ }
- /* Figure mag^2 of each resampled fx_int */
- tmax[0] = (t1.real*t1.real) + (t1.imag*t1.imag);
- tmax[1] = (t2.real*t2.real) + (t2.imag*t2.imag);
+ float max = tmax[0]; /* Maximum for figuring correct symbol */
+ float min = tmax[0];
+ int sym = 0; /* Index of maximum */
+ for( m=0; m<M; m++){
+ if(tmax[m]>max){
+ max = tmax[m];
+ sym = m;
+ }
+ if(tmax[m]<min){
+ min = tmax[m];
+ }
+ }
/* Get the actual bit */
if(rx_bits != NULL){
- rx_bits[i] = (tmax[1]>tmax[0])?1:0;
+ /* Get bits for 2FSK and 4FSK */
+ /* TODO: Replace this with something more generic maybe */
+ if(M==2){
+ rx_bits[i] = sym==1; /* 2FSK. 1 bit per symbol */
+ }else if(M==4){
+ rx_bits[(i*2)+1] = (sym&0x1); /* 4FSK. 2 bits per symbol */
+ rx_bits[(i*2) ] = (sym&0x2)>>1;
+ }
}
+
/* Produce soft decision symbols */
if(rx_sd != NULL){
- rx_sd[i] = sqrtf(tmax[0]) - sqrtf(tmax[1]);
+ /* Convert symbols from max^2 into max */
+ for( m=0; m<M; m++)
+ tmax[m] = sqrtf(tmax[m]);
+
+ if(M==2){
+ rx_sd[i] = tmax[0] - tmax[1];
+ }else if(M==4){
+ /* TODO: Find a soft-decision mode that works for 4FSK */
+ min = sqrtf(min);
+ rx_sd[(i*2)+1] = - tmax[0] ; /* Bits=00 */
+ rx_sd[(i*2) ] = - tmax[0] ;
+ rx_sd[(i*2)+1]+= tmax[1] ; /* Bits=01 */
+ rx_sd[(i*2) ]+= - tmax[1] ;
+ rx_sd[(i*2)+1]+= - tmax[2] ; /* Bits=10 */
+ rx_sd[(i*2) ]+= tmax[2] ;
+ rx_sd[(i*2)+1]+= tmax[3] ; /* Bits=11 */
+ rx_sd[(i*2) ]+= tmax[3] ;
+ }
}
/* Accumulate resampled int magnitude for EbNodB estimation */
/* Standard deviation is calculated by algorithm devised by crafty soviets */
#ifdef EST_EBNO
/* Accumulate the square of the sampled value */
- ft1 = tmax[ (tmax[1]>tmax[0]) ];
+ ft1 = max;
stdebno += ft1;
/* Figure the abs value of the max tone */
neyesamp = fsk->stats->neyesamp = P*2;
neyeoffset = high_sample+1+(P*28);
- fsk->stats->neyetr = fsk->mode*3;
- for(j=0; j<neyesamp; j++)
- fsk->stats->rx_eye[0][j] = cabsolute(f1_int[neyeoffset+j]);
- for(j=0; j<neyesamp; j++)
- fsk->stats->rx_eye[1][j] = cabsolute(f2_int[neyeoffset+j]);
- for(j=0; j<neyesamp; j++)
- fsk->stats->rx_eye[2][j] = cabsolute(f1_int[neyeoffset+neyesamp+j]);
- for(j=0; j<neyesamp; j++)
- fsk->stats->rx_eye[3][j] = cabsolute(f2_int[neyeoffset+neyesamp+j]);
- for(j=0; j<neyesamp; j++)
- fsk->stats->rx_eye[4][j] = cabsolute(f1_int[neyeoffset+2*neyesamp+j]);
- for(j=0; j<neyesamp; j++)
- fsk->stats->rx_eye[5][j] = cabsolute(f2_int[neyeoffset+2*neyesamp+j]);
+ int eye_traces = MODEM_STATS_ET_MAX/M;
+
+ fsk->stats->neyetr = fsk->mode*eye_traces;
+ for( i=0; i<eye_traces; i++){
+ for ( m=0; m<M; m++){
+ for(j=0; j<neyesamp; j++)
+ fsk->stats->rx_eye[i*M+m][j] = cabsolute(f_int[m][neyesamp*i+neyeoffset+j]);
+ }
+ }
eye_max = 0;
/* Normalize eye to +/- 1 */
- for(i=0; i<fsk->mode*3; i++)
+ for(i=0; i<M*eye_traces; i++)
for(j=0; j<neyesamp; j++)
if(fabsf(fsk->stats->rx_eye[i][j])>eye_max)
eye_max = fabsf(fsk->stats->rx_eye[i][j]);
- for(i=0; i<fsk->mode*3; i++)
+ for(i=0; i<M*eye_traces; i++)
for(j=0; j<neyesamp; j++)
fsk->stats->rx_eye[i][j] = fsk->stats->rx_eye[i][j]/eye_max;
/* Dump some internal samples */
modem_probe_samp_f("t_EbNodB",&(fsk->EbNodB),1);
modem_probe_samp_f("t_ppm",&(fsk->ppm),1);
- modem_probe_samp_f("t_f1",&f_est[0],1);
- modem_probe_samp_f("t_f2",&f_est[1],1);
- modem_probe_samp_c("t_f1_int",f1_int,(nsym+1)*P);
- modem_probe_samp_c("t_f2_int",f2_int,(nsym+1)*P);
modem_probe_samp_f("t_rx_timing",&(rx_timing),1);
- #ifndef DEMOD_ALLOC_STACK
- free(f1_int);
- free(f2_int);
- free(f1_intbuf);
- free(f2_intbuf);
- #endif
-}
-
-void fsk4_demod(struct FSK *fsk, uint8_t rx_bits[], COMP fsk_in[]){
- int N = fsk->N;
- int Ts = fsk->Ts;
- int Rs = fsk->Rs;
- int Fs = fsk->Fs;
- int nsym = fsk->Nsym;
- int nin = fsk->nin;
- int P = fsk->P;
- int Nmem = fsk->Nmem;
- int M = fsk->mode;
- int i,j,dc_i,cbuf_i;
- float ft1;
- int nstash = fsk->nstash;
- COMP *f1_int, *f2_int, *f3_int, *f4_int;
- COMP t1,t2,t3,t4;
- COMP phi1_c = fsk->phi1_c;
- COMP phi2_c = fsk->phi2_c;
- COMP phi3_c = fsk->phi3_c;
- COMP phi4_c = fsk->phi4_c;
- COMP phi_ft;
- int nold = Nmem-nin;
- COMP dphi1,dphi2,dphi3,dphi4;
- COMP dphift;
- float rx_timing,norm_rx_timing,old_norm_rx_timing,d_norm_rx_timing,appm;
- int using_old_samps;
- COMP *sample_src;
- COMP *f1_intbuf,*f2_intbuf,*f3_intbuf,*f4_intbuf;
- float f_est[M],fc_avg,fc_tx;
- float meanebno,stdebno,eye_max;
- int neyesamp,neyeoffset;
-
- /* Estimate tone frequencies */
- fsk_demod_freq_est(fsk,fsk_in,f_est,M);
- modem_probe_samp_f("t_f_est",f_est,M);
-
- #ifdef DEMOD_ALLOC_STACK
- /* allocate memory for the integrated samples */
- /* Note: This must be kept after fsk_demod_freq_est for memory usage reasons */
- f1_int = (COMP*) alloca(sizeof(COMP)*(nsym+1)*P);
- f2_int = (COMP*) alloca(sizeof(COMP)*(nsym+1)*P);
- f3_int = (COMP*) alloca(sizeof(COMP)*(nsym+1)*P);
- f4_int = (COMP*) alloca(sizeof(COMP)*(nsym+1)*P);
-
- /* Allocate circular buffers for integration */
- f1_intbuf = (COMP*) alloca(sizeof(COMP)*Ts);
- f2_intbuf = (COMP*) alloca(sizeof(COMP)*Ts);
- f3_intbuf = (COMP*) alloca(sizeof(COMP)*Ts);
- f4_intbuf = (COMP*) alloca(sizeof(COMP)*Ts);
- #else
- f1_int = (COMP*) malloc(sizeof(COMP)*(nsym+1)*P);
- f2_int = (COMP*) malloc(sizeof(COMP)*(nsym+1)*P);
- f3_int = (COMP*) malloc(sizeof(COMP)*(nsym+1)*P);
- f4_int = (COMP*) malloc(sizeof(COMP)*(nsym+1)*P);
-
- f1_intbuf = (COMP*) malloc(sizeof(COMP)*Ts);
- f2_intbuf = (COMP*) malloc(sizeof(COMP)*Ts);
- f3_intbuf = (COMP*) malloc(sizeof(COMP)*Ts);
- f4_intbuf = (COMP*) malloc(sizeof(COMP)*Ts);
- #endif
- /* If this is the first run, we won't have any valid f_est */
- if(fsk->f1_est<1){
- fsk->f1_est = f_est[0];
- fsk->f2_est = f_est[1];
- fsk->f3_est = f_est[2];
- fsk->f4_est = f_est[3];
- }
-
- /* Back the stored phase off to account for re-integraton of old samples */
- dphi1 = comp_exp_j(-2*(Nmem-nin-(Ts/P))*M_PI*((fsk->f1_est)/(float)(Fs)));
- dphi2 = comp_exp_j(-2*(Nmem-nin-(Ts/P))*M_PI*((fsk->f2_est)/(float)(Fs)));
- dphi3 = comp_exp_j(-2*(Nmem-nin-(Ts/P))*M_PI*((fsk->f3_est)/(float)(Fs)));
- dphi4 = comp_exp_j(-2*(Nmem-nin-(Ts/P))*M_PI*((fsk->f4_est)/(float)(Fs)));
-
- phi1_c = cmult(dphi1,phi1_c);
- phi2_c = cmult(dphi2,phi2_c);
- phi3_c = cmult(dphi3,phi3_c);
- phi4_c = cmult(dphi4,phi4_c);
-
- /* Figure out how much to nudge each sample downmixer for every sample */
- dphi1 = comp_exp_j(2*M_PI*((fsk->f1_est)/(float)(Fs)));
- dphi2 = comp_exp_j(2*M_PI*((fsk->f2_est)/(float)(Fs)));
- dphi3 = comp_exp_j(2*M_PI*((fsk->f3_est)/(float)(Fs)));
- dphi4 = comp_exp_j(2*M_PI*((fsk->f4_est)/(float)(Fs)));
-
- dc_i = 0;
- cbuf_i = 0;
- sample_src = &(fsk->samp_old[nstash-nold]);
- using_old_samps = 1;
-
- /* Pre-fill integration buffer */
- for(dc_i=0; dc_i<Ts-(Ts/P); dc_i++){
- /* Switch sample source to new samples when we run out of old ones */
- if(dc_i>=nold && using_old_samps){
- sample_src = &fsk_in[0];
- dc_i = 0;
- using_old_samps = 0;
-
- /* Recalculate delta-phi after switching to new sample source */
- phi1_c = comp_normalize(phi1_c);
- phi2_c = comp_normalize(phi2_c);
- phi3_c = comp_normalize(phi3_c);
- phi4_c = comp_normalize(phi4_c);
- dphi1 = comp_exp_j(2*M_PI*((f_est[0])/(float)(Fs)));
- dphi2 = comp_exp_j(2*M_PI*((f_est[1])/(float)(Fs)));
- dphi3 = comp_exp_j(2*M_PI*((f_est[2])/(float)(Fs)));
- dphi4 = comp_exp_j(2*M_PI*((f_est[3])/(float)(Fs)));
- }
- /* Downconvert and place into integration buffer */
- f1_intbuf[dc_i]=cmult(sample_src[dc_i],phi1_c);
- f2_intbuf[dc_i]=cmult(sample_src[dc_i],phi2_c);
- f3_intbuf[dc_i]=cmult(sample_src[dc_i],phi3_c);
- f4_intbuf[dc_i]=cmult(sample_src[dc_i],phi4_c);
-
- modem_probe_samp_c("t_f1_dc",&f1_intbuf[dc_i],1);
- modem_probe_samp_c("t_f2_dc",&f2_intbuf[dc_i],1);
- modem_probe_samp_c("t_f3_dc",&f3_intbuf[dc_i],1);
- modem_probe_samp_c("t_f4_dc",&f4_intbuf[dc_i],1);
- /* Spin downconversion phases */
- phi1_c = cmult(phi1_c,dphi1);
- phi2_c = cmult(phi2_c,dphi2);
- phi3_c = cmult(phi3_c,dphi3);
- phi4_c = cmult(phi4_c,dphi4);
+ #ifdef MODEMPROBE_ENABLE
+ for( m=0; m<M; m++){
+ snprintf(mp_name_tmp,19,"t_f%zd_int",m+1);
+ modem_probe_samp_c(mp_name_tmp,f_int[m],(nsym+1)*P);
+ snprintf(mp_name_tmp,19,"t_f%zd",m+1);
+ modem_probe_samp_f(mp_name_tmp,&f_est[m],1);
}
- cbuf_i = dc_i;
-
- /* Integrate over Ts at offsets of Ts/P */
- for(i=0; i<(nsym+1)*P; i++){
- /* Downconvert and Place Ts/P samples in the integration buffers */
- for(j=0; j<(Ts/P); j++,dc_i++){
- /* Switch sample source to new samples when we run out of old ones */
- if(dc_i>=nold && using_old_samps){
- sample_src = &fsk_in[0];
- dc_i = 0;
- using_old_samps = 0;
-
- /* Recalculate delta-phi after switching to new sample source */
- phi1_c = comp_normalize(phi1_c);
- phi2_c = comp_normalize(phi2_c);
- phi3_c = comp_normalize(phi3_c);
- phi4_c = comp_normalize(phi4_c);
- dphi1 = comp_exp_j(2*M_PI*((f_est[0])/(float)(Fs)));
- dphi2 = comp_exp_j(2*M_PI*((f_est[1])/(float)(Fs)));
- dphi3 = comp_exp_j(2*M_PI*((f_est[2])/(float)(Fs)));
- dphi4 = comp_exp_j(2*M_PI*((f_est[3])/(float)(Fs)));
- }
- /* Downconvert and place into integration buffer */
- f1_intbuf[cbuf_i+j]=cmult(sample_src[dc_i],phi1_c);
- f2_intbuf[cbuf_i+j]=cmult(sample_src[dc_i],phi2_c);
- f3_intbuf[cbuf_i+j]=cmult(sample_src[dc_i],phi3_c);
- f4_intbuf[cbuf_i+j]=cmult(sample_src[dc_i],phi4_c);
-
- modem_probe_samp_c("t_f1_dc",&f1_intbuf[cbuf_i+j],1);
- modem_probe_samp_c("t_f2_dc",&f2_intbuf[cbuf_i+j],1);
- modem_probe_samp_c("t_f3_dc",&f3_intbuf[cbuf_i+j],1);
- modem_probe_samp_c("t_f4_dc",&f4_intbuf[cbuf_i+j],1);
- /* Spin downconversion phases */
- phi1_c = cmult(phi1_c,dphi1);
- phi2_c = cmult(phi2_c,dphi2);
- phi3_c = cmult(phi3_c,dphi3);
- phi4_c = cmult(phi4_c,dphi4);
-
- }
-
- /* Dump internal samples */
-
- cbuf_i += Ts/P;
- if(cbuf_i>=Ts) cbuf_i = 0;
- /* Integrate over the integration buffers, save samples */
- t1 = t2 = t3 = t4 = comp0();
- for(j=0; j<Ts; j++){
- t1 = cadd(t1,f1_intbuf[j]);
- t2 = cadd(t2,f2_intbuf[j]);
- t3 = cadd(t3,f3_intbuf[j]);
- t4 = cadd(t4,f4_intbuf[j]);
- }
- f1_int[i] = t1;
- f2_int[i] = t2;
- f3_int[i] = t3;
- f4_int[i] = t4;
-
- }
-
- fsk->phi1_c = phi1_c;
- fsk->phi2_c = phi2_c;
- fsk->phi3_c = phi3_c;
- fsk->phi4_c = phi4_c;
-
- fsk->f1_est = f_est[0];
- fsk->f2_est = f_est[1];
- fsk->f3_est = f_est[2];
- fsk->f4_est = f_est[3];
-
- /* Stash samples away in the old sample buffer for the next round of bit getting */
- memcpy((void*)&(fsk->samp_old[0]),(void*)&(fsk_in[nin-nstash]),sizeof(COMP)*nstash);
-
- /* Fine Timing Estimation */
- /* Apply magic nonlinearity to f1_int and f2_int, shift down to 0,
- * exract angle */
-
- /* Figure out how much to spin the oscillator to extract magic spectral line */
- dphift = comp_exp_j(-2*M_PI*((float)(Rs)/(float)(P*Rs)));
- phi_ft.real = 1;
- phi_ft.imag = 0;
- t1=comp0();
- COMP c,y,t;
- c = comp0();
- t2 = comp0();
- for(i=0; i<(nsym+1)*P; i++){
- /* Get abs^2 of fx_int[i], and add 'em */
- ft1 = (f1_int[i].real*f1_int[i].real) + (f1_int[i].imag*f1_int[i].imag);
- ft1 += (f2_int[i].real*f2_int[i].real) + (f2_int[i].imag*f2_int[i].imag);
- ft1 += (f3_int[i].real*f3_int[i].real) + (f3_int[i].imag*f3_int[i].imag);
- ft1 += (f4_int[i].real*f4_int[i].real) + (f4_int[i].imag*f4_int[i].imag);
-
- /* Down shift and accumulate magic line */
- t1 = fcmult(ft1,phi_ft);
- y.real = t1.real-c.real;
- y.imag = t1.imag-c.imag;
-
- t.real = t2.real + y.real;
- t.imag = t2.imag + y.imag;
-
- c.real = (t.real-t2.real) - y.real;
- c.imag = (t.imag-t2.imag) - y.imag;
-
- t2 = cadd(t2,t1);
-
- /* Spin the oscillator for the magic line shift */
- phi_ft = cmult(phi_ft,dphift);
- }
- t1 = t2;
- /* Get the magic angle */
- norm_rx_timing = -atan2f(t1.imag,t1.real)/(2*M_PI);
- rx_timing = norm_rx_timing*(float)P;
-
- old_norm_rx_timing = fsk->norm_rx_timing;
- fsk->norm_rx_timing = norm_rx_timing;
-
- /* Estimate sample clock offset */
- d_norm_rx_timing = norm_rx_timing - old_norm_rx_timing;
-
- /* Filter out big jumps in due to nin change */
- if(fabsf(d_norm_rx_timing) < .2){
- appm = 1e6*d_norm_rx_timing/(float)nsym;
- fsk->ppm = .9*fsk->ppm + .1*appm;
- }
-
- /* Figure out how many samples are needed the next modem cycle */
- if(norm_rx_timing > 0.25){
- fsk->nin = N+Ts/2;
- }
- else if(norm_rx_timing < -0.25){
- fsk->nin = N-Ts/2;
- }
- else
- fsk->nin = N;
-
- modem_probe_samp_f("t_norm_rx_timing",&(norm_rx_timing),1);
- modem_probe_samp_i("t_nin",&(fsk->nin),1);
-
- /* Re-sample the integrators with linear interpolation magic */
- int low_sample = (int)floorf(rx_timing);
- float fract = rx_timing - (float)low_sample;
- int high_sample = (int)ceilf(rx_timing);
-
- /* Vars for finding the max-of-4 for each bit */
- float tmax[4];
- float max = 0;
- int sym = 0;
-
- #ifdef EST_EBNO
- meanebno = 0;
- stdebno = 0;
- #endif
-
- /* FINALLY, THE BITS */
- /* also, resample fx_int */
- for(i=0; i<nsym; i++){
- int st = (i+1)*P;
- t1 = fcmult(1-fract,f1_int[st+ low_sample]);
- t1 = cadd(t1,fcmult( fract,f1_int[st+high_sample]));
- t2 = fcmult(1-fract,f2_int[st+ low_sample]);
- t2 = cadd(t2,fcmult( fract,f2_int[st+high_sample]));
- t3 = fcmult(1-fract,f3_int[st+ low_sample]);
- t3 = cadd(t3,fcmult( fract,f3_int[st+high_sample]));
- t4 = fcmult(1-fract,f4_int[st+ low_sample]);
- t4 = cadd(t4,fcmult( fract,f4_int[st+high_sample]));
-
- /* Figure mag^2 of each resampled fx_int */
- tmax[0] = (t1.real*t1.real) + (t1.imag*t1.imag);
- tmax[1] = (t2.real*t2.real) + (t2.imag*t2.imag);
- tmax[2] = (t3.real*t3.real) + (t3.imag*t3.imag);
- tmax[3] = (t4.real*t4.real) + (t4.imag*t4.imag);
-
- /* Find the maximum symbol */
- max = 0;
- sym = 0;
- for(j=0; j<4; j++){
- if(tmax[j]>max){
- sym = j;
- max = tmax[j];
- }
- }
-
- /* Turn into bits */
- rx_bits[(i*2)+1] = (sym&0x1);
- rx_bits[(i*2) ] = (sym&0x2)>>1;
-
- /* Accumulate resampled int magnitude for EbNodB estimation */
- /* Standard deviation is calculated by algorithm devised by crafty soviets */
- #ifdef EST_EBNO
- /* Accumulate the square of the sampled value */
- ft1 = max;
- stdebno += ft1;
-
- /* Figure the abs value of the max tone */
- meanebno += sqrtf(ft1);
- #endif
- /* Soft output goes here */
- }
-
- #ifdef EST_EBNO
- /* Calculate mean for EbNodB estimation */
- meanebno = meanebno/(float)nsym;
-
- /* Calculate the std. dev for EbNodB estimate */
- stdebno = (stdebno/(float)nsym) - (meanebno*meanebno);
- stdebno = sqrt(stdebno);
-
- fsk->EbNodB = -6+(20*log10f((1e-6+meanebno)/(1e-6+stdebno)));
- #else
- fsk->EbNodB = 1;
#endif
- /* Write some statistics out to the stats struct, if present */
- if( fsk->stats != NULL ){
- /* Save clock offset in ppm */
- fsk->stats->clock_offset = fsk->ppm;
-
- /* Calculate and save SNR from EbNodB estimate */
- fsk->stats->snr_est = .5*fsk->stats->snr_est + .5*fsk->EbNodB;//+ 10*log10f(((float)Rs)/((float)Rs*M));
-
- /* Save rx timing */
- fsk->stats->rx_timing = (float)rx_timing;
-
- /* Estimate and save frequency offset */
- fc_avg = (f_est[0]+f_est[1]+f_est[3]+f_est[2])/4;
- fc_tx = (fsk->f1_tx+fsk->f1_tx+fsk->fs_tx)/2;
- fsk->stats->foff = fc_tx-fc_avg;
-
- /* Take a sample for the eye diagrams */
- neyesamp = fsk->stats->neyesamp = P*2;
- neyeoffset = low_sample+1+(P*(nsym/4));
- fsk->stats->neyetr = fsk->mode*2;
-
- for(j=0; j<neyesamp; j++)
- fsk->stats->rx_eye[0][j] = cabsolute(f1_int[neyeoffset+j]);
- for(j=0; j<neyesamp; j++)
- fsk->stats->rx_eye[1][j] = cabsolute(f2_int[neyeoffset+j]);
- for(j=0; j<neyesamp; j++)
- fsk->stats->rx_eye[2][j] = cabsolute(f3_int[neyeoffset+j]);
- for(j=0; j<neyesamp; j++)
- fsk->stats->rx_eye[3][j] = cabsolute(f4_int[neyeoffset+j]);
- for(j=0; j<neyesamp; j++)
- fsk->stats->rx_eye[4][j] = cabsolute(f1_int[neyeoffset+neyesamp+j]);
- for(j=0; j<neyesamp; j++)
- fsk->stats->rx_eye[5][j] = cabsolute(f2_int[neyeoffset+neyesamp+j]);
- for(j=0; j<neyesamp; j++)
- fsk->stats->rx_eye[6][j] = cabsolute(f3_int[neyeoffset+neyesamp+j]);
- for(j=0; j<neyesamp; j++)
- fsk->stats->rx_eye[7][j] = cabsolute(f4_int[neyeoffset+neyesamp+j]);
-
- eye_max = 0;
- /* Normalize eye to +/- 1 */
- for(i=0; i<fsk->mode*2; i++)
- for(j=0; j<neyesamp; j++)
- if(fabsf(fsk->stats->rx_eye[i][j])>eye_max)
- eye_max = fabsf(fsk->stats->rx_eye[i][j]);
-
- for(i=0; i<fsk->mode*2; i++)
- for(j=0; j<neyesamp; j++)
- fsk->stats->rx_eye[i][j] = fsk->stats->rx_eye[i][j]/eye_max;
-
- fsk->stats->nr = 0;
- fsk->stats->Nc = 0;
- }
-
- /* Dump some internal samples */
- modem_probe_samp_f("t_EbNodB",&(fsk->EbNodB),1);
- modem_probe_samp_f("t_ppm",&(fsk->ppm),1);
- modem_probe_samp_f("t_f1",&f_est[0],1);
- modem_probe_samp_f("t_f2",&f_est[1],1);
- modem_probe_samp_f("t_f3",&f_est[2],1);
- modem_probe_samp_f("t_f4",&f_est[3],1);
- modem_probe_samp_c("t_f1_int",f1_int,(nsym+1)*P);
- modem_probe_samp_c("t_f2_int",f2_int,(nsym+1)*P);
- modem_probe_samp_c("t_f3_int",f3_int,(nsym+1)*P);
- modem_probe_samp_c("t_f4_int",f4_int,(nsym+1)*P);
- modem_probe_samp_f("t_rx_timing",&(rx_timing),1);
-
#ifndef DEMOD_ALLOC_STACK
- free(f1_int);
- free(f2_int);
- free(f3_int);
- free(f4_int);
- free(f1_intbuf);
- free(f2_intbuf);
- free(f3_intbuf);
- free(f4_intbuf);
+ for( m=0; m<M; m++){
+ free(f_int[m]);
+ }
+ free(f_intbuf_m);
#endif
}
-
void fsk_demod(struct FSK *fsk, uint8_t rx_bits[], COMP fsk_in[]){
- if(fsk->mode == 4){
- fsk4_demod(fsk,rx_bits,fsk_in);
- }else{
- fsk2_demod(fsk,rx_bits,NULL,fsk_in);
- }
+ fsk2_demod(fsk,rx_bits,NULL,fsk_in);
}
void fsk_demod_sd(struct FSK *fsk, float rx_sd[], COMP fsk_in[]){
- if(fsk->mode == 4){
- assert(0);
- //TODO: Add 4FSK soft decision
- //fsk4_demod(fsk,rx_bits,fsk_in);
- }else{
- fsk2_demod(fsk,NULL,rx_sd,fsk_in);
- }
+ fsk2_demod(fsk,NULL,rx_sd,fsk_in);
}
void fsk_mod(struct FSK *fsk,float fsk_out[],uint8_t tx_bits[]){
dosc_f[3] = comp_exp_j(2*M_PI*((float)(f1_tx+fs_tx*3)/(float)(Fs)));
if(fsk->mode == 2){
- /* Outer loop through bits */
- for(i=0; i<fsk->Nsym; i++){
- /* select current bit phase shift */
- dph = tx_bits[i]==0?dosc_f[0]:dosc_f[1];
- for(j=0; j<Ts; j++){
- tx_phase_c = cmult(tx_phase_c,dph);
- fsk_out[i*Ts+j] = 2*tx_phase_c.real;
- }
- }
- }else {
- /* Same thing as above, but with more bits and phases */
- for(i=0; i<fsk->Nsym; i++){
- /* select current bit phase shift */
- sym = tx_bits[ i*2 ]==0?0:2;
- sym+= tx_bits[(i*2)+1]==0?0:1;
- dph = dosc_f[sym];
- for(j=0; j<Ts; j++){
- tx_phase_c = cmult(tx_phase_c,dph);
- fsk_out[i*Ts+j] = 2*tx_phase_c.real;
- }
- }
- }
+ /* Outer loop through bits */
+ for(i=0; i<fsk->Nsym; i++){
+ /* select current bit phase shift */
+ dph = tx_bits[i]==0?dosc_f[0]:dosc_f[1];
+ for(j=0; j<Ts; j++){
+ tx_phase_c = cmult(tx_phase_c,dph);
+ fsk_out[i*Ts+j] = 2*tx_phase_c.real;
+ }
+ }
+ }else {
+ /* Same thing as above, but with more bits and phases */
+ for(i=0; i<fsk->Nsym; i++){
+ /* select current bit phase shift */
+ sym = tx_bits[ i*2 ]==0?0:2;
+ sym+= tx_bits[(i*2)+1]==0?0:1;
+ dph = dosc_f[sym];
+ for(j=0; j<Ts; j++){
+ tx_phase_c = cmult(tx_phase_c,dph);
+ fsk_out[i*Ts+j] = 2*tx_phase_c.real;
+ }
+ }
+ }
/* Normalize TX phase to prevent drift */
tx_phase_c = comp_normalize(tx_phase_c);
projects / freetel-svn-tracking.git / commitdiff