Multichannel CW decoder implemented for FLDIGI.

README

@@ -88,7 +88,30 @@ MORSE - PROJECT IDEAS
 		http://orgmode.org/worg/org-contrib/babel/examples/data-collection-analysis.html
 	
 
-
+3. CW Skimmer  type functionality 
+	Automatically detect CW signals in the baseband  
+
+		- initialize 
+	do 
+		- get input buffer  (512 samples * 1/Fs) (Fs=4000 Hz)
+		- calculate FFT 
+		- find peaks in power spectrum  Ps
+			- Fpeak = peak_detect(Ps,delta)
+			- integrate Fpeak over N timeslots  (64 .. 128 ms ? ) 
+
+		- calculate noise floor level  
+			 - noisemax => frequency bins from 1 to first detected peak 
+			 - fbin  => freq bin size 
+			 - Pxx  => power spectrum  
+				=>   Nrms = sqrt(sum(Pxx(1:noisemax)*fbin)) / sqrt(f(noisemax));
+			- update delta & threshold 
+		- calculate SNR of found Fpeak
+			-  integrate Srms = sqrt(sum(Fpeak +/- 10 Hz)*fbin)) 
+		 	- SNR = Srms / Nrms 
+		if (SNR >  threshold )
+			Run decoder instance on detected signal frequency 
+	while (timer > 
+	
 
 
 

src/bmorse.cxx

@@ -58,7 +58,7 @@
 	int bfv;				// 0 
 	double frequency;		// 600 
 	double sample_duration; // 5
-	double sample_rate; 	// 0
+	double sample_rate; 	// 4000
 	double delta;			// 10.0
 	double amplify;			// 0.0
 	int fft;				// 0 
@@ -275,6 +275,21 @@ void apply_window (double * data, int datalen)
 	return ;
 } /* apply_window */
 
+double calc_SNR(double *data, int len, double fbin)
+{
+	double CG,NG;
+	int i;
+	
+	for (i=0; i< len; i++) {
+		CG += data[i];
+		NG += data[i]*data[i];
+	}
+	CG = CG/N;
+	NG = NG/N;
+
+	
+}
+
 void interp_spec (float * mag, int maglen, const double *spec, int speclen)
 {
 	int k, lastspec = 0 ;
@@ -360,9 +375,76 @@ void process_data(double x)
 int rx_FFTprocess(const double *buf, int len)
 {
 	complex  z, *zp;
-	int n,i;
+	int n,i,speclen,Hz;
 	static int smpl_ctr = 0;
 	static double FFTvalue,FFTphase =0.0; 
+	fftw_plan plan; 
+	double single_max,noise_sum,sig_sum,Nrms,Srms,fbin;
+	double time_domain[1024];
+	double freq_domain[1024];
+	double single_mag_spec[1024];
+	struct PEAKS p;
+
+	p.delta = params.delta;
+	speclen = 512;
+
+	for (i=0; i< len; i++) 
+		time_domain[i] = buf[i];
+	
+	
+	plan = fftw_plan_r2r_1d (2*speclen, time_domain, freq_domain, FFTW_R2HC, FFTW_MEASURE | FFTW_PRESERVE_INPUT) ;
+	if (plan == NULL)
+	{	printf ("%s : line %d : create plan failed.\n", __FILE__, __LINE__) ;
+		exit (1) ;
+		} ;
+	
+
+//	calculate FFT 
+	apply_window (time_domain, 2*speclen) ;
+	fftw_execute (plan) ;
+	single_max = calc_magnitude (freq_domain, 2*speclen, single_mag_spec) ;
+
+// find peaks in power spectrum  Ps
+//			- Fpeak = peak_detect(Ps,delta)
+//			- integrate Fpeak over N timeslots  (64 .. 128 ms ? ) 
+
+	peak_detect(single_mag_spec, 2*speclen, &p);
+
+	// print found freq peaks - only once
+	if (1 ) {
+		for (i=0; i <p.mxcount; i++) {
+			Hz = (p.mxpos[i]*(4000/2))/(speclen);
+			printf("peak[%d]:%f\tHz:%d\tmaxcount:%d\n",p.mxpos[i],p.mx[i],Hz,p.mxcount);
+		}
+	}
+	params.frequency = Hz;
+/*
+		- calculate noise floor level  
+			 - noisemax => frequency bins from 1 to first detected peak 
+			 - fbin  => freq bin size 
+			 - Pxx  => power spectrum  512
+				=>   Nrms = sqrt(sum(Pxx(1:noisemax)*fbin)) / sqrt(f(noisemax));
+			- update delta & threshold 
+*/
+	fbin = 4000./1024;
+	noise_sum = 0.;
+	for (i = 10; i<p.mxpos[0]-10; i++) {
+		noise_sum += single_mag_spec[i]; 
+	}
+	printf("\n noise_sum:%f bins:%d",noise_sum,p.mxpos[0]-10);
+	Nrms = sqrt(noise_sum* fbin)/sqrt(Hz);
+
+	sig_sum = 0.;
+	for (i = p.mxpos[0]-5; i< p.mxpos[0]+5; i++) {
+		sig_sum += single_mag_spec[i];
+	}	
+	Srms = sqrt (sig_sum*fbin);
+	printf("\n SNR = %5.2f S:%f ss:%f N:%f  Hz:%d", Srms/Nrms, Srms, sig_sum,Nrms,Hz); 
+
+/*		- calculate SNR of found Fpeak
+			-  integrate Srms = sqrt(sum(Fpeak +/- 10 Hz)*fbin)) 
+		 	- SNR = Srms / Nrms 
+*/
 
 	while (len-- > 0) {
 		// convert CW signal to baseband 	

src/transl.cxx

@@ -57,7 +57,7 @@ struct TREE {	// Tree structure to decode dit/dah sequence to corresponding char
  {55,00,"Z"},	// --..
  {57,00,"Q"},	// --.-
  {54,00,"Ö"},	// ---.	Ö
- {56,57,"Š"},	// ----	Š
+ {56,57,"*----*"},	// ----	Š
  {00,00,"5"},	// .....
  {00,00,"4"},	// ....-
  {00,60,"*...-.*"},	// ...-.
@@ -68,36 +68,39 @@ struct TREE {	// Tree structure to decode dit/dah sequence to corresponding char
  {00,00,"2"},	// ..---
  {00,00,"*.-...*"},	// .-...
  {00,00,"e"},	// .-..-
- {00,63,"+"},	// .-.-.
- {00,00,"*.-.--*"},	// .-.--
+ {00,63,"<AR>"},	// .-.-.
+ {00,00,"*"},	// .-.--
  {00,00,"*.--..*"},	// .--..
  {59,00,"a"},	// .--.-
  {00,00,"*.---.*"},	// .---.
  {00,00,"1"},	// .----
  {00,00,"6"},	// -....
- {61,00,"="},	// -...-
+ {61,00,"<BT>"},	// -...-
  {00,00,"/"},	// -..-.
  {00,00,"*-..--*"},	// -..--
  {00,00,"*-.-..*"},	// -.-..
  {00,00,"^H"},	// -.-.-
- {00,00,"~N"},	// -.--.
+ {00,00,"<KN>"},	// -.--.
  {00,00,"8"},	// ---..
  {00,00,"7"},	// --...
  {00,00,"9"},	// ----.
  {00,00,"0"},	// -----
  {00,00,"?"},	// ..--..
  {00,00,"@"},	// .--.-.
- {00,00,"SK"},	// ...-.-
+ {00,00,"<SK>"},	// ...-.-
  {00,62,"*-...-.*"},	// -...-.
- {00,00,"BK"},	// -...-.-
- {00,00,"."}	// .-.-.-
+ {00,00,"<BK>"},	// -...-.-
+ {00,00,"."},	// .-.-.-
+ {00,65,"*--..-*"},	// --..-
+ {00,00,","},	// --..--
+ {00,00,"'"}	// .----.
 }; 
 
 
 
 
 //***********************************************************************************
-// (c) 2013  AG1LE Mauri Niininen
+// (c) 2013,2014  AG1LE Mauri Niininen
 //
 //
 int morse::transl_(int *ltr)