Good working model with random sync symbols rather than sweeping sync.

lib/superfox/ftrsd3.f90

@@ -74,6 +74,7 @@ subroutine ftrsd3(s3,chansym0,rxdat,rxprob,rxdat2,rxprob2,ntrials0,  &
   numera=0
   workdat=rxdat
   call rs_decode_sf(workdat,era_pos,numera,nerr)    !Call the decoder
+  nerr=-1
 
   if(nerr.ge.0) then
 ! Hard-decision decoding succeeded.  Save codeword and some parameters.
@@ -87,7 +88,6 @@ subroutine ftrsd3(s3,chansym0,rxdat,rxprob,rxdat2,rxprob2,ntrials0,  &
      param(5)=0
      param(7)=1000*1000               !???
      ntry=0
-!     print*,'AA1',nerr
      go to 900
   endif
 
@@ -129,11 +129,6 @@ subroutine ftrsd3(s3,chansym0,rxdat,rxprob,rxdat2,rxprob2,ntrials0,  &
         j=indexes(NN-1-i)
         thresh=thresh0(i)
 ! Generate a random number ir, 0 <= ir <= 100 (see POSIX.1-2001 example).
-!        nseed=nseed*1103515245 + 12345
-!        ir=mod(nseed/65536,32768)
-!        ir=(100*ir)/32768
-!        nseed=iand(ir,2147483647)
-
         ir=100.0*ran1(nseed)
         if((ir.lt.thresh) .and. numera.lt. 0.69*(NN-KK)) then
            era_pos(numera)=j
@@ -144,7 +139,6 @@ subroutine ftrsd3(s3,chansym0,rxdat,rxprob,rxdat2,rxprob2,ntrials0,  &
         endif
      enddo
      call rs_decode_sf(workdat,era_pos,numera,nerr)    !Call the decoder
-
      if( nerr.ge.0) then
       ! We have a candidate codeword.  Find its hard and soft distance from
       ! the received word.  Also find pp1 and pp2 from the full array 
@@ -163,6 +157,8 @@ subroutine ftrsd3(s3,chansym0,rxdat,rxprob,rxdat2,rxprob2,ntrials0,  &
 
         pp=0.
         call getpp3(s3,workdat,pp)
+!        write(*,5001) ncandidates,nhard,nsoft,ntotal,pp,pp1,pp2
+!5001    format(4i8,3f7.3)
         if(pp.gt.pp1) then
            pp2=pp1
            pp1=pp
@@ -191,6 +187,6 @@ subroutine ftrsd3(s3,chansym0,rxdat,rxprob,rxdat2,rxprob2,ntrials0,  &
   param(7)=1000.0*pp2
   param(8)=1000.0*pp1
   if(param(0).eq.0) param(2)=-1
-!write(*,*) ntry,ncandidates,nera_best,nhard_min,nsoft_min,ntotal_min,pp1,pp2
+
 900 return
 end subroutine ftrsd3

lib/superfox/sfox_gen.f90

@@ -1,9 +1,10 @@
-subroutine sfox_gen(idat,f0,fsample,cdat)
+subroutine sfox_gen(idat,f0,fsample,isync,cdat)
 
   use sfox_mod
   complex cdat(NMAX)                     !Generated complex waveform
   complex w,wstep
   integer idat(NN)
+  integer isync(50)
 
   twopi=8.0*atan(1.0)
   tsync=NS*NSPS/fsample

lib/superfox/sfox_mod.f90

@@ -2,7 +2,6 @@ module sfox_mod
   
   parameter (NMAX=15*12000)       !Samples in iwave (180,000)
   integer MM,NQ,NN,KK,ND1,ND2,NFZ,NSPS,NS,NSYNC,NZ,NFFT,NFFT1
-  integer isync(50)
 
 contains
   subroutine sfox_init(mm0,nn0,kk0,itu,fspread,delay,fsample,ts)

lib/superfox/sfox_sync.f90

@@ -1,11 +1,13 @@
-subroutine sfox_sync(crcvd,fsample,f,t)
+subroutine sfox_sync(crcvd,fsample,isync,f,t,f1,xdt)
 
   use sfox_mod
   complex crcvd(NMAX)                      !Signal as received
   complex, allocatable :: c(:)             !Work array
+  integer isync(50)
   real, allocatable :: s(:,:)              !Symbol spectra, 1/8 symbol steps
-!  character*1 line(-30:30),mark(0:5)
+  real, allocatable :: ccf(:,:)            !
-!  data mark/' ','.','-','+','X','$'/
+  character*1 line(-30:30),mark(0:6)
+  data mark/' ','.','-','+','X','$','#'/
 
   nh=NFFT1/2                               !1024
   istep=nh/8                               !128
@@ -16,6 +18,7 @@ subroutine sfox_sync(crcvd,fsample,f,t)
   allocate(c(0:nfft1-1))
   allocate(s(nh/2,nsz))
 
+! Compute symbol spectra with df=baud/2 and 1/8 symbol steps.  
   ia=1-istep
   fac=1.0/NFFT1
   do j=1,nsz
@@ -35,7 +38,9 @@ subroutine sfox_sync(crcvd,fsample,f,t)
   i0=nint(1500.0/df)
   ipk=-999
   jpk=-999
-  do j=1,nsz-8*NS
+  jz=nsz-8*NS
+  allocate(ccf(-iz:iz,1:jz))
+  do j=1,jz
      do i=-iz,iz
         p=0.
         do k=1,NS
@@ -43,6 +48,7 @@ subroutine sfox_sync(crcvd,fsample,f,t)
            jj=j + 8*(k-1)
            p=p + s(ii,jj)
         enddo
+        ccf(i,j)=p
         if(p.gt.pmax) then
            pmax=p
            ipk=i
@@ -54,6 +60,23 @@ subroutine sfox_sync(crcvd,fsample,f,t)
   dfreq=ipk*df
   f=1500.0+dfreq
   t=(jpk-201)*istep/fsample
+  if(NS.ne.-99) go to 900
 
-  return
+  ferr=f-f1
+  terr=t-xdt
+  if(abs(ferr).lt.5.357 .and. abs(terr).lt.0.0233) go to 900
+
+  ccf=ccf/pmax
+  do j=jpk-10,jpk+10
+     do i=-iz,iz
+        k=6.001*ccf(i,j)
+        line(i)=mark(k)
+     enddo
+     write(*,1000) j,line(-iz:iz)
+1000 format(i5,2x,61a1)
+  enddo
+  write(*,1100) ferr,terr
+1100 format('ferr:',f7.1,'   terr:',f7.2)
+
+900 return
 end subroutine sfox_sync

lib/superfox/sfoxtest.f90

@@ -10,6 +10,7 @@ program sfoxtest
   type(hdr) h                            !Header for .wav file
   integer*2 iwave(NMAX)                  !Generated i*2 waveform
   integer param(0:8)
+  integer isync(50)
   real*4 xnoise(NMAX)                    !Random noise
   real*4 dat(NMAX)                       !Generated real data
   complex cdat(NMAX)                     !Generated complex waveform
@@ -108,6 +109,7 @@ program sfoxtest
 ! Generate a sync pattern
   do i=1,NS
      isync(i)=NQ*ran1(idummy)
+     if(i.gt.20) isync(i)=NQ/2
   enddo
 
 ! Generate a message
@@ -124,7 +126,7 @@ program sfoxtest
 
 ! Generate cdat, the SuperFox waveform
   call timer('gen     ',0)
-  call sfox_gen(chansym0,f0,fsample,cdat)
+  call sfox_gen(chansym0,f0,fsample,isync,cdat)
   call timer('gen     ',1)
   isnr0=-8
 
@@ -158,7 +160,7 @@ program sfoxtest
            f1=1500.0 + 20.0*(ran1(idummy)-0.5)
            xdt=0.3*ran1(idummy)
            call timer('gen     ',0)
-           call sfox_gen(chansym0,f1,fsample,cdat)
+           call sfox_gen(chansym0,f1,fsample,isync,cdat)
            call timer('gen     ',1)
         endif
         
@@ -181,7 +183,7 @@ program sfoxtest
         else
 ! Find signal freq and DT
            call timer('sync    ',0)
-           call sfox_sync(crcvd,fsample,f,t)
+           call sfox_sync(crcvd,fsample,isync,f,t,f1,xdt)
            call timer('sync    ',1)
         endif
         ferr=f-f1
@@ -234,7 +236,6 @@ program sfoxtest
            close(10)
        endif
 
-!        if(nharderr.le.maxerr) ngood=ngood+1
        if(count(correct.ne.chansym0).eq.0) ngood=ngood+1
      enddo  ! ifile
      fgoodsync=float(ngoodsync)/nfiles