Use GFSK for SuperFox fox transmissions.

CMakeLists.txt

@@ -587,6 +587,7 @@ set (wsjt_FSRCS
   lib/fst4/fst4_baseline.f90
   lib/77bit/hash22calc.f90
   lib/superfox/sfox_wave.f90
+  lib/superfox/sfox_wave_gfsk.f90
   )
 
 # temporary workaround for a gfortran v7.3 ICE on Fedora 27 64-bit

Modulator/Modulator.cpp

@@ -70,7 +70,8 @@ void Modulator::start (QString mode, unsigned symbolsLength, double framesPerSym
   m_bFastMode=fastMode;
   m_TRperiod=TRperiod;
   unsigned delay_ms=1000;
-  if(mode=="FT8" or (mode=="FST4" and m_nsps==720)) delay_ms=500; //FT8, FST4-15
+  if((mode=="FT8" and m_nsps==1920) or (mode=="FST4" and m_nsps==720)) delay_ms=500;  //FT8, FST4-15
+  if((mode=="FT8" and m_nsps==1024)) delay_ms=400;            //SuperFox Qary Polar Code transmission
   if(mode=="Q65" and m_nsps<=3600) delay_ms=500;              //Q65-15 and Q65-30
   if(mode=="FT4") delay_ms=300;                               //FT4
 

lib/superfox/sfox_wave_gfsk.f90

@@ -0,0 +1,78 @@
+subroutine sfox_wave_gfsk(fname)
+
+! Called by WSJT-X when it's time for SuperFox to transmit.  Reads array
+! itone(1:151) from disk file 'sfox_2.dat' in the writable data directory.
+! Generates a GFSK waveform with short ramp-up and ramp-down symbols of 
+! duration NSPS/BT at the beginning and end of the waveform.
+
+  parameter (NWAVE=(160+2)*134400*4) !Max WSJT-X waveform (FST4-1800 at 48kHz)
+  parameter (NSYM=151,NSPS=1024*4)
+  parameter (NPTS=(NSYM+2)*NSPS)
+  parameter (BT=8)
+  character*(*) fname
+  integer itone(151)
+  real*8 dt,twopi,f0,baud,phi,dphi_peak
+  real*8 dphi(0:NPTS-1)
+  real*8 pulse(3*NSPS)
+  logical first/.true./
+
+  common/foxcom/wave(NWAVE)
+  save first,twopi,dt,hmod,dphi_peak,pulse
+
+  if(first) then
+    fsample=48000.0
+    twopi=8.d0*atan(1.d0)
+    dt=1.d0/fsample
+    hmod=1.0
+    dphi_peak=twopi*hmod/real(NSPS)
+    do i=1,3*NSPS 
+      tt=(i-1.5*nsps)/real(nsps)
+      pulse(i)=gfsk_pulse(BT,tt)
+    enddo
+    first=.false.
+  endif
+ 
+  open(25,file=trim(fname),status='unknown',err=999)
+  read(25,'(20i4)',err=999,end=999) itone
+  close(25)
+  if(itone(1).lt.0 .or. itone(1).gt.128) go to 999
+
+! Generate the SuperFox waveform.
+  
+  dphi=0.d0
+  do j=1,NSYM
+    ib=(j-1)*NSPS
+    ie=ib+3*NSPS-1
+    dphi(ib:ie)=dphi(ib:ie)+dphi_peak*pulse(1:3*NSPS)*itone(j)
+  enddo
+  dphi(0:2*NSPS-1)=dphi(0:2*NSPS-1)+dphi_peak*itone(1)*pulse(NSPS+1:3*NSPS)
+  dphi(NSYM*NSPS:(NSYM+2)*NSPS-1)=dphi(NSYM*NSPS:(NSYM+2)*NSPS-1)+dphi_peak*itone(NSYM)*pulse(1:2*NSPS)
+
+  wave=0.
+  phi=0.d0
+  f0=750.0d0
+  dphi=dphi+twopi*f0*dt
+  k=0
+  do j=1,NSPS*(NSYM+2)-1
+    k=k+1
+    wave(k)=sin(phi)
+    phi=phi+dphi(j)
+  enddo
+  
+! Add raised cosine ramps at the beginning and end of the waveform.
+! Since the modulator expects an integral number of symbols, dummy
+! symbols are added to the beginning and end of the waveform to 
+! hold the ramps. All but nramp of the samples in each dummy
+! symbol will be zero.
+ 
+  nramp=NSPS/BT
+  wave(1:NSPS-nramp)=0.0
+  wave(NSPS-nramp+1:NSPS)=wave(NSPS-nramp+1:NSPS) *                   &
+       (1.0-cos(twopi*(/(i,i=0,nramp-1)/)/(2.0*nramp)))/2.0
+  k1=(NSYM+1)*NSPS+1
+  wave(k1:k1+nramp-1)=wave(k1:k1+nramp-1) *                           &
+       (1.0+cos(twopi*(/(i,i=0,nramp-1)/)/(2.0*nramp)))/2.0
+  wave(k1+nramp:NPTS)=0.0
+
+999 return
+end subroutine sfox_wave_gfsk

widgets/mainwindow.cpp

@@ -178,7 +178,7 @@ extern "C" {
 
   void foxgen_(bool* bSuperFox, char const * fname, FCL len);
 
-  void sfox_wave_(char const * fname, FCL len);
+  void sfox_wave_gfsk_(char const * fname, FCL len);
 
   void plotsave_(float swide[], int* m_w , int* m_h1, int* irow);
 
@@ -11020,5 +11020,5 @@ void MainWindow::sfox_tx()
   p2.start(QDir::toNativeSeparators(m_appDir)+QDir::separator()+"sftx", args);
   p2.waitForFinished();
   auto fname2 {QDir::toNativeSeparators(m_config.writeable_data_dir().absoluteFilePath("sfox_2.dat")).toLocal8Bit()};
-  sfox_wave_(fname2.constData(), (FCL)fname2.size());
+  sfox_wave_gfsk_(fname2.constData(), (FCL)fname2.size());
 }

widgets/mainwindow.h

@@ -50,7 +50,7 @@
 #define NUM_MSK144_SYMBOLS 144             //s8 + d48 + s8 + d80
 #define NUM_Q65_SYMBOLS 85                 //63 data + 22 sync
 #define NUM_FT8_SYMBOLS 79
-#define NUM_SUPERFOX_SYMBOLS 151
+#define NUM_SUPERFOX_SYMBOLS 153         //24 sync + 127 data + 2 ramp up/down
 #define NUM_FT4_SYMBOLS 105
 #define NUM_FST4_SYMBOLS 160             //240/2 data + 5*8 sync
 #define NUM_CW_SYMBOLS 250