More work toward testing Q65-style sync.

lib/superfox/sfox_gen.f90

@@ -13,14 +13,15 @@ subroutine sfox_gen(idat,f0,fsample,isync,cdat)
   j=1
   k=0
   do i=1,NDS
-     if(j.le.NS .and. i.eq.isync(min(j,NS))) then
+     if(j.le.NS .and. i.eq.isync(j)) then
-        j=j+1                   !Index for next sync symbol
+        if(j.lt.NS) j=j+1       !Index for next sync symbol
         itone(i)=0              !Insert sync symbol at tone 0
      else
         k=k+1
         itone(i)=idat(k) + 1    !Symbol value 0 is transmitted at tone 1, etc.
      endif
   enddo
+!  print*,'aaa',NN,k,NS,isync(NS),NDS
   
   df=fsample/NSPS
   w=1.0

lib/superfox/sfox_mod.f90

@@ -1,7 +1,8 @@
 module sfox_mod
   
   parameter (NMAX=15*12000)       !Samples in iwave (180,000)
-  integer MM,NQ,NN,KK,NS,NDS,NFZ,NSPS,NSYNC,NZ,NFFT,NFFT1
+  integer MM,NQ,NN,KK,NS,NDS,NFZ,NSPS,NSYNC,NZ,NFFT1
+  real baud,tsym,bw
 
 contains
   subroutine sfox_init(mm0,nn0,kk0,itu,fspread,delay,fsample,ns0)
@@ -29,8 +30,11 @@ contains
     NSPS=isps(iloc(1))  !Samples per symbol
     NSYNC=NS*NSPS       !Samples in sync waveform
     NZ=NSPS*NDS         !Samples in full Tx waveform
-    NFFT=32768          !Length of FFT for sync waveform
     NFFT1=2*NSPS        !Length of FFTs for symbol spectra
+    
+    baud=fsample/NSPS
+    tsym=1.0/baud
+    bw=NQ*baud
 
     fspread=0.0
     delay=0.0

lib/superfox/sfox_sync.f90

@@ -1,38 +1,111 @@
-subroutine sfox_sync(crcvd,fsample,isync,f,t)
+subroutine sfox_sync(iwave,fsample,isync,f,t)
 
   use sfox_mod
   parameter (NSTEPS=8)
-  complex crcvd(NMAX)                      !Signal as received
+  integer*2 iwave(NMAX)
+  integer isync(44)
+  integer ipeak(1)
   complex, allocatable :: c(:)             !Work array
-  integer isync(50)
+  real x(171)
-  real, allocatable :: s(:,:)              !Symbol spectra, 1/8 symbol steps
+  real, allocatable :: s(:,:)              !Symbol spectra, stepped by NSTEPS 
+  real, allocatable :: savg(:)             !Average spectrum
   real, allocatable :: ccf(:,:)            !
-!  character*1 line(-30:30),mark(0:6)
+  character*1 line(-15:15),mark(0:6),c1
-!  data mark/' ','.','-','+','X','$','#'/
+  data mark/' ','.','-','+','X','$','#'/
 
-  nh=NFFT1/2                               !1024
+  nh=NFFT1/2
-  istep=nh/NSTEPS                          !128
+  istep=NSPS/NSTEPS
-  nsz=(nint(3.0*fsample) + NS*NSPS)/istep  !473
+  jz=(13.5*fsample)/istep
-  df=fsample/NFFT1                         !5.86 Hz
+  df=fsample/NFFT1
-  tstep=istep/fsample                      !0.0107 s
+  tstep=istep/fsample
+  x=0.
+  do i=1,NS
+     x(isync(i))=1.0
+  enddo
 
-  allocate(c(0:nfft1-1))
+  allocate(s(0:nh/2,jz))
-  allocate(s(nh/2,nsz))
+  allocate(savg(0:nh/2))
+  allocate(c(0:NFFT1-1))
 
-! Compute symbol spectra with df=baud/2 and NSTEPS steps per symbol.
+  s=0.
-  ia=1-istep
+  savg=0.
   fac=1.0/NFFT1
-  do j=1,nsz
+! Compute symbol spectra with df=baud/2 and NSTEPS steps per symbol.
-     ia=ia+istep
+  do j=1,jz
-     ib=ia+nh-1
+     k=(j-1)*istep
-     c(0:NSPS-1)=fac*crcvd(ia:ib)
+     do i=0,nh-1
-     c(NSPS:)=0.
+        c(i)=cmplx(fac*iwave(k+2*i+1),fac*iwave(k+2*i+2))
-     call four2a(c,NFFT1,1,-1,1)
+     enddo
-     do i=1,nh/2
+     c(nh:)=0.
-        s(i,j)=real(c(i))**2 + aimag(c(i))**2
+     call four2a(c,NFFT1,1,-1,0)           !Forward FFT, r2c
+     do i=0,nh/2
+        p=real(c(i))*real(c(i)) + aimag(c(i))*aimag(c(i))
+        s(i,j)=p
+        savg(i)=savg(i) + p
      enddo
   enddo
 
+  pmax=maxval(s(82:112,1:jz))
+  s=s/pmax
+  do j=jz,1,-1
+     do i=-15,15
+        k=6.001*s(97+i,j)
+        line(i)=mark(k)
+     enddo
+     c1=' '
+     k=j/NSTEPS + 1
+     if(k.le.171) then
+        if(x(k).ne.0.0) c1='*'
+     endif
+!     write(*,2001) j,c1,line
+!2001 format(i3,2x,a1,' |',31a1,'|')
+     xx=0
+     if(c1.eq.'*') xx=1
+     write(44,3044) j*tstep,xx,3.5*s(96:98,j)
+3044 format(f10.4,4f10.4)
+  enddo
+     
+  savg=savg/jz
+  ipeak=maxloc(savg(82:112))
+  i0=ipeak(1)+81
+  dxi=0.
+!  if(i0.gt.0 .and. i0.lt.nh/2) then
+!     call peakup(savg(i0-1),savg(i0),savg(i0+1),dxi)
+!  endif
+  f=(i0+dxi)*df + bw/2.0
+
+  do j=1,jz
+     k=j/NSTEPS + 1
+     xx=0
+     if(k.le.171) xx=x(k)
+     write(43,3043) j,s(i0,j),xx
+3043 format(i5,2f12.3)
+  enddo
+  lagmax=1.0/tstep + 1
+  pmax=0.
+  lagpk=-99
+!  print*,i0,jz,tstep,lagmax
+  do lag=0,lagmax
+     p=0.
+     do i=1,NS
+        k=NSTEPS*(isync(i)-1) + 1 + lag
+        p=p + s(i0,k)
+     enddo
+     p=p/NS
+     if(p.gt.pmax) then
+        pmax=p
+        lagpk=lag
+     endif
+     write(42,3042) lag,lag*tstep,p
+3042 format(i5,2f15.3)
+  enddo
+  t=lagpk*tstep
+!  print*,f,t
+  if(NS.ne.-99) return
+  
+  nsz=(nint(3.0*fsample) + NS*NSPS)/istep
+
+
   pmax=0.
   ntol=100
   iz=nint(ntol/df)

lib/superfox/sfoxtest.f90

@@ -37,8 +37,6 @@ program sfoxtest
             116, 122, 130, 131, 134, 136, 137, 140, 146, 154,  &
             159, 161, 163, 165/
 
-
-
   nargs=iargc()
   if(nargs.ne.11) then
      print*,'Usage:   sfoxtest  f0   DT  ITU M  N   K NS v hs nfiles snr'
@@ -81,16 +79,12 @@ program sfoxtest
 
   fsample=12000.0                   !Sample rate (Hz)
   call sfox_init(mm0,nn0,kk0,itu,fspread,delay,fsample,ns0)
-  baud=fsample/NSPS
-  tsym=1.0/baud
-  bw=NQ*baud
-  maxerr=(NN-KK)/2
   tsync=NSYNC/fsample
   txt=(NN+NS)*NSPS/fsample
 
   write(*,1000) MM,NN,KK,NSPS,baud,bw,itu,tsync,txt
 1000 format('M:',i2,'   Base code: (',i3,',',i3,')   NSPS:',i5,   &
-          '   Baud:',f7.3,'   BW:',f6.0/                   &
+          '   Baud:',f7.3,'   BW:',f9.3/                   &
           'Channel: ',a2,'   Tsync:',f4.1,'   TxT:',f5.1/)
 
 ! Allocate storage for arrays that depend on code parameters.
@@ -170,7 +164,8 @@ program sfoxtest
         call timer('watterso',1)
         crcvd=sig*crcvd+cnoise
 
-        dat=aimag(sigr*cdat(1:NMAX)) + xnoise     !Add generated AWGN noise
+!        dat=aimag(sigr*cdat(1:NMAX)) + xnoise     !Add generated AWGN noise
+        dat=aimag(sigr*crcvd(1:NMAX)) + xnoise     !Add generated AWGN noise
         fac=32767.0
         if(snr.ge.90.0) iwave(1:NMAX)=nint(fac*dat(1:NMAX))
         if(snr.lt.90.0) iwave(1:NMAX)=nint(rms*dat(1:NMAX))
@@ -181,12 +176,13 @@ program sfoxtest
         else
 ! Find signal freq and DT
            call timer('sync    ',0)
-           call sfox_sync(crcvd,fsample,isync,f,t)
+           call sfox_sync(iwave,fsample,isync,f,t)
            call timer('sync    ',1)
         endif
-
         ferr=f-f1
         terr=t-xdt
+!        write(*,4100) f1,f,ferr,xdt,t,terr
+!4100    format(3f10.1,3f10.3)
 
         igoodsync=0
         if(abs(ferr).lt.baud/2.0 .and. abs(terr).lt.tsym/4.0) then