wspr5d_exp now tries to detect sequences of 3, 6, and 9 bits.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7700 ab8295b8-cf94-4d9e-aec4-7959e3be5d79

lib/fsk4hf/bpdecode300.f90

@@ -647,9 +647,14 @@ do iter=0,maxiterations
   enddo
 !write(*,*) 'number of unsatisfied parity checks ',ncheck
   if( ncheck .eq. 0 ) then ! we have a codeword - reorder the columns and return it
-    niterations=iter
+!    niterations=iter
     codeword=cw(colorder+1)
     decoded=codeword(M+1:N)
+    nerr=0
+    do i=1,N
+      if( (2*cw(i)-1)*llr(i) .lt. 0.0 ) nerr=nerr+1
+    enddo
+    niterations=nerr
     return
   endif
 

lib/fsk4hf/getfc2w.f90

@@ -20,16 +20,8 @@ subroutine getfc2w(c,csync,npeaks,fs,fc1,fpks)
 
   ia=nint(0.75*baud/df) 
   cs(ia:NZ-1-ia)=0.                  !Save only freqs around fc1
-!  do i=1,NZ/2
-!    filt=1/(1+((i*df)**2/(0.50*baud)**2)**8)
-!    cs(i)=cs(i)*filt
-!    cs(NZ+1-i)=cs(NZ+1-i)*filt
-!  enddo 
   call four2a(cs,NZ,1,1,1)           !Back to time domain
   cs=cs/NZ
-!do i=0,NZ-1
-!write(51,*) i,real(cs(i)),imag(cs(i))
-!enddo
   cs=cs*cs                           !Square the data
   call four2a(cs,NZ,1,-1,1)          !Compute squared spectrum
 
@@ -37,7 +29,6 @@ subroutine getfc2w(c,csync,npeaks,fs,fc1,fpks)
   pmax=0.
   fc2=0.
   ja=nint(0.3*baud/df)
-!  ja=nint(0.5*baud/df)
   k=1
   do j=-ja,ja
      f2=j*df

lib/fsk4hf/osd300.f90

@@ -80,9 +80,6 @@ do id=1,K ! diagonal element indices
 enddo
 
 g2=transpose(genmrb)
-!do i=1,N
-!  g2(i,1:K)=genmrb(1:K,i)
-!enddo
 
 ! The hard decisions for the K MRB bits define the order 0 message, m0. 
 ! Encode m0 using the modified generator matrix to find the "order 0" codeword. 
@@ -140,8 +137,13 @@ enddo
 
 ! re-order the codeword to place message bits at the end
 cw(indices)=cw
+hdec(indices)=hdec
 decoded=cw(M+1:N)
-niterations=1
+nerr=0
+do i=1,N
+  if( hdec(i) .ne. cw(i) ) nerr=nerr+1
+enddo
+niterations=nerr
 return
 end subroutine osd300
 

lib/fsk4hf/wspr5d.f90

@@ -122,10 +122,10 @@ program wspr5d
         go to 999
      endif
      close(10)
-     fa=102.0
+     fa=100.0
      fb=150.0
      call getfc1w(c,fs,fa,fb,fc1,xsnr)         !First approx for freq
-npeaks=20
+     npeaks=20
      call getfc2w(c,csync,npeaks,fs,fc1,fpks)      !Refined freq
 
      a(1)=-fc1
@@ -152,6 +152,7 @@ npeaks=20
            ibb=NZ-1-j
         endif
         z=sum(c(ia:ib)*conjg(csync(iaa:ibb)))
+write(51,*) j/fs,real(z),imag(z)
         if(abs(z).gt.amax) then
            amax=abs(z)
            jpk=j

lib/fsk4hf/wspr5d_exp.f90

@@ -7,18 +7,33 @@ program wspr5d
 !
 ! Still to do: find and decode more than one signal in the specified passband.
 
-  include 'wsprlf_params.f90'
+!  include 'wsprlf_params.f90'
+
+  parameter (NDOWN=30)
+  parameter (KK=60)
+  parameter (ND=300)
+  parameter (NS=109)
+  parameter (NR=3)
+  parameter (NN=NR+NS+ND)
+  parameter (NSPS0=8640)
+  parameter (NSPS=16)
+  parameter (N2=2*NSPS)
+  parameter (NZ=NSPS*NN)
+  parameter (NZ400=288*NN)
   parameter (NMAX=300*12000)
+
   character arg*8,message*22,cbits*50,infile*80,fname*16,datetime*11
   character*120 data_dir
   complex csync(0:NZ-1)                 !Sync symbols only, from cbb
+  complex c400(0:NZ400-1)                     !Complex waveform
   complex c(0:NZ-1)                     !Complex waveform
-  complex cd(0:412*16-1)                    !Complex waveform
+  complex cd(0:NZ-1)                    !Complex waveform
-  complex ca(0:412*16-1)                    !Complex waveform
+  complex ca(0:NZ-1)                    !Complex waveform
+  complex zz
   real*8 fMHz
   real rxdata(ND),llr(ND)               !Soft symbols
   real pp(32)                       !Shaped pulse for OQPSK
-  real ps(0:7),sbits(412)
+  real sbits(412),softbits(9)
   real fpks(20)
   integer id(NS+ND)                     !NRZ values (+/-1) for Sync and Data
   integer isync(48)                     !Long sync vector
@@ -28,7 +43,7 @@ program wspr5d
   integer*2 iwave(NMAX)                 !Generated full-length waveform  
   integer*1 idat(7)
   integer*1 decoded(KK),apmask(ND),cw(ND)
-  integer*1 hbits(412),ebits(411),bits(5)
+  integer*1 hbits(412),bits(13)
   data ib13/1,1,1,1,1,-1,-1,1,1,-1,1,-1,1/
 
   nargs=iargc()
@@ -98,53 +113,68 @@ program wspr5d
     j1=index(infile,'.c5')
     j2=index(infile,'.wav')
     if(j1.gt.0) then
-       read(10,end=999) fname,ntrmin,fMHz,c
+       read(10,end=999) fname,ntrmin,fMHz,c400
        read(fname(8:11),*) nutc
        write(datetime,'(i11)') nutc
     else if(j2.gt.0) then
        read(10,end=999) ihdr,iwave
        read(infile(j2-4:j2-1),*) nutc
        datetime=infile(j2-11:j2-1)
-       call wspr5_downsample(iwave,c)
+       call wspr5_downsample(iwave,c400)
     else
        print*,'Wrong file format?'
        go to 999
     endif
-
     close(10)
+
+
     fa=100.0
-    fb=170.0
+    fb=150.0
-    call getfc1w(c,fs,fa,fb,fc1,xsnr)         !First approx for freq
+    fs400=400.0
-!    call getfc2w(c,csync,fs,fc1,fc2,fc3)      !Refined freq
+    call getfc1(c400,fs400,fa,fb,fc1,xsnr)         !First approx for freq
+!write(*,*) datetime,'initial guess ',fc1
     npeaks=5
-    call getfc2w(c,csync,npeaks,fs,fc1,fpks)      !Refined freq
+    call getfc2(c400,npeaks,fs400,fc1,fpks)      !Refined freq
+    do idf=1,npeaks ! consider the top npeak peaks 
+      fc2=fpks(idf)
+!write(*,*) 'peak ',idf,fc1+fc2,fc2
+      call downsample(c400,fc1+fc2,cd)
+      s2=sum(cd*conjg(cd))/(16*412)
+      cd=cd/sqrt(s2)
      
-!write(*,*) fc1+fc2
+      do is=0,11  ! search over plus/minus 0.25 seconds for now
-do ipks=1,npeaks
-    call downsample(c,fc1+fpks(ipks),cd)
-
-  do ncoh=1,1,-1
-    do is=0,9
         idt=is/2
-      if( mod(is,2).eq. 1 ) idt=-is/2 
+        if( mod(is,2).eq. 1 ) idt=-(is+1)/2 
-      xdt=idt/22.222
+        xdt=real(22+idt)/22.222 - 1.0
-      k=-1
         ca=cshift(cd,22+idt)
-      do i=1,408,4
+        do iseq=1,3  ! try sequence estimation lengths of 3, 6, and 9 bits.
-        k=k+2
+          k=1-2*iseq
+          nseq=iseq*3
+          do i=1,408,iseq*4
+            k=k+iseq*2
             j=(i+1)*16
-        call mskseqdet(ca(j),pp,id(k),bits,ps,ncoh)
+            call mskseqdet(nseq,ca(j),pp,id(k),softbits,1,phase)
-        r1=max(ps(1),ps(3),ps(5),ps(7))-max(ps(0),ps(2),ps(4),ps(6))
+            hbits(i:i+iseq*4)=bits
-        r2=max(ps(2),ps(3),ps(6),ps(7))-max(ps(0),ps(1),ps(4),ps(5))
+            sbits(i:i+iseq*4)=bits
-        r4=max(ps(4),ps(5),ps(6),ps(7))-max(ps(0),ps(1),ps(2),ps(3))
-        hbits(i:i+4)=bits
-        sbits(i:i+4)=bits
-        sbits(i+1)=r4
-        sbits(i+2)=r2
-        if( id(k+1) .ne. 0 ) sbits(i+2)=id(k+1)*25
-        sbits(i+3)=r1
-      enddo
 
+            sbits(i+1)=softbits(1)
+            sbits(i+2)=softbits(2)
+            if( id(k+1) .ne. 0 ) sbits(i+2)=id(k+1)*25
+              sbits(i+3)=softbits(3)
+
+            if( iseq .ge. 2 ) then
+              sbits(i+5)=softbits(4)
+              sbits(i+6)=softbits(5)
+            if( id(k+3) .ne. 0 ) sbits(i+6)=id(k+3)*25
+              sbits(i+7)=softbits(6)
+              if( iseq .eq. 3 ) then
+                sbits(i+9)=softbits(7)
+                sbits(i+10)=softbits(8)
+                if( id(k+5) .ne. 0 ) sbits(i+10)=id(k+5)*25
+                sbits(i+11)=softbits(9)
+              endif
+            endif
+          enddo
           j=1
           do i=1,205
             if( abs(id(i)) .ne. 2 ) then
@@ -160,13 +190,15 @@ do ipks=1,npeaks
           rx2av=sum(rxdata*rxdata)/ND
           rxsig=sqrt(rx2av-rxav*rxav)
           rxdata=rxdata/rxsig
-      sigma=0.84
+!          sigma=0.84
+          sigma=1.20
           llr=2*rxdata/(sigma*sigma)
           apmask=0
           max_iterations=40
           ifer=0
           nbadcrc=0
           call bpdecode300(llr,apmask,max_iterations,decoded,niterations,cw)
+! niterations will be equal to the Hamming distance between hard received word and the codeword
           if(niterations.lt.0) call osd300(llr,3,decoded,niterations,cw)
           if(niterations.ge.0) call chkcrc10(decoded,nbadcrc)
           if(niterations.lt.0 .or. nbadcrc.ne.0) ifer=1
@@ -182,33 +214,50 @@ do ipks=1,npeaks
             nfdot=0
             write(13,1210) datetime,0,nsnr,xdt,freq,message,nfdot
 1210        format(a11,2i4,f6.2,f12.7,2x,a22,i3)
-        write(*,1212) datetime(8:11),nsnr,xdt,freq,nfdot,message,'*',ipks
+            write(*,1212) datetime(8:11),nsnr,xdt,freq,nfdot,message,'*',idf,nseq,is,niterations
-1212 format(a4,i4,f5.1,f11.6,i3,2x,a22,a1,i4)
+1212        format(a4,i4,f5.1,f11.6,i3,2x,a22,a1,i3,i3,i3,i4)
             goto 888
           endif
+        enddo !iseq
+      enddo
+    enddo
+888 continue
   enddo
-enddo
-enddo ! fpeaks loop
-888  enddo
 
   write(*,1120)
 1120 format("<DecodeFinished>")
 
 999 end program wspr5d
 
-subroutine mskseqdet(cdat,pp,bsync,bestbits,cmbest,ncoh)
+subroutine getmetric(ib,ps,xmet)
-complex cdat(16*4),cbest(16*4),cideal(16*4)
+  real ps(0:511)
-complex cdf(16*4),cfac
+  xm1=0
-real cm(0:7),cmbest(0:7)
+  xm0=0
-real pp(32)
+  do i=0,511
-integer*1 bits(5),bestbits(5),sgn(5)
+    if( iand(i/ib,1) .eq. 1 .and. ps(i) .gt. xm1 ) xm1=ps(i)
-integer bsync(3)
+    if( iand(i/ib,1) .eq. 0 .and. ps(i) .gt. xm0 ) xm0=ps(i)
+  enddo
+  xmet=xm1-xm0
+  return
+end subroutine getmetric
+
+subroutine mskseqdet(ns,cdat,pp,bsync,softbits,ncoh,phase)
+!
+! Detect sequences of 3, 6, or 9 bits (ns).
+! Sync bits are assumed to be known. 
+!
+complex cdat(16*12),cbest(16*12),cideal(16*12)
+complex cdf(16*12),cfac,zz
+real cm(0:511),cmbest(0:511)
+real pp(32),softbits(9)
+integer bit(13),bestbits(13),sgn(13)
+integer bsync(7)
 
 twopi=8.0*atan(1.0)
 dt=30.0*18.0/12000.0
 cmax=0;
 fbest=0.0;
-
+np=2**ns-1
 idfmax=40
 if( ncoh .eq. 1 ) idfmax=0
 do idf=0,idfmax
@@ -217,40 +266,88 @@ do idf=0,idfmax
   dphi=twopi*deltaf*dt
   cfac=cmplx(cos(dphi),sin(dphi)) 
   cdf=1.0
-  do i=2,16*4
+  do i=2,16*(ns-1)
     cdf(i)=cdf(i-1)*cfac
   enddo 
 
   cm=0
   ibflag=0
-  do i=0,7
+  do i=0,np
-    bits(1)=(bsync(1)+2)/4
+    bit(1)=(bsync(1)+2)/4
-    bits(2)=iand(i/4,1)
+    bit(2)=iand(i/(2**(ns-1)),1)
-    bits(3)=iand(i/2,1)
+    bit(3)=iand(i/(2**(ns-2)),1)
     if( bsync(2).ne.0 ) then ! force the barker bits
-      bits(3)=(bsync(2)+2)/4
+      bit(3)=(bsync(2)+2)/4
+    endif
+    bit(4)=iand(i/(2**(ns-3)),1)
+    bit(5)=(bsync(3)+2)/4
+
+    if( ns .ge. 6 ) then
+      bit(6)=iand(i/(2**(ns-4)),1)
+      bit(7)=iand(i/(2**(ns-5)),1)
+      if( bsync(4).ne.0 ) then ! force the barker bits
+        bit(7)=(bsync(4)+2)/4
+      endif
+      bit(8)=iand(i/(2**(ns-6)),1)
+      bit(9)=(bsync(5)+2)/4
+      if( ns .eq. 9 ) then
+        bit(10)=iand(i/4,1)
+        bit(11)=iand(i/2,1)
+        if( bsync(6).ne.0 ) then ! force the barker bits
+          bit(11)=(bsync(6)+2)/4
+        endif
+        bit(12)=iand(i/1,1)
+        bit(13)=(bsync(7)+2)/4
+      endif
+    endif
+
+    sgn=2*bit-1
+    cideal(1:16)   =cmplx(sgn(1)*pp(17:32),sgn(2)*pp(1:16))
+    cideal(17:32)  =cmplx(sgn(3)*pp(1:16),sgn(2)*pp(17:32))
+    cideal(33:48)  =cmplx(sgn(3)*pp(17:32),sgn(4)*pp(1:16))
+    cideal(49:64)  =cmplx(sgn(5)*pp(1:16),sgn(4)*pp(17:32))
+    if( ns .ge. 6 ) then
+      cideal(65:80)  =cmplx(sgn(5)*pp(17:32),sgn(6)*pp(1:16))
+      cideal(81:96)  =cmplx(sgn(7)*pp(1:16),sgn(6)*pp(17:32))
+      cideal(97:112) =cmplx(sgn(7)*pp(17:32),sgn(8)*pp(1:16))
+      cideal(113:128)=cmplx(sgn(9)*pp(1:16),sgn(8)*pp(17:32))
+      if( ns .eq. 9 ) then
+        cideal(129:144)  =cmplx(sgn(9)*pp(17:32),sgn(10)*pp(1:16))
+        cideal(145:160)  =cmplx(sgn(11)*pp(1:16),sgn(10)*pp(17:32))
+        cideal(161:176) =cmplx(sgn(11)*pp(17:32),sgn(12)*pp(1:16))
+        cideal(177:192)=cmplx(sgn(13)*pp(1:16),sgn(12)*pp(17:32))
+      endif
     endif
-    bits(4)=iand(i/1,1)
-    bits(5)=(bsync(3)+2)/4
-    sgn=2*bits-1
-    cideal(1:16)=cmplx(sgn(1)*pp(17:32),sgn(2)*pp(1:16))
-    cideal(17:32)=cmplx(sgn(3)*pp(1:16),sgn(2)*pp(17:32))
-    cideal(33:48)=cmplx(sgn(3)*pp(17:32),sgn(4)*pp(1:16))
-    cideal(49:64)=cmplx(sgn(5)*pp(1:16),sgn(4)*pp(17:32))
     cideal=cideal*cdf
-    cm(i)=abs(sum(cdat*conjg(cideal)))/1.e3
+    cm(i)=abs(sum(cdat(1:64*ns/3)*conjg(cideal(1:64*ns/3))))/1.e3
     if( cm(i) .gt. cmax ) then
       ibflag=1
       cmax=cm(i)
-      bestbits=bits
+      bestbits=bit
       cbest=cideal
       fbest=deltaf
+      zz=sum(cdat*conjg(cbest))/1.e3
+      phase=atan2(imag(zz),real(zz))
     endif
   enddo
   if( ibflag .eq. 1 ) then ! new best found
     cmbest=cm
   endif
 enddo
+softbits=0.0
+call getmetric(1,cmbest,softbits(ns))
+call getmetric(2,cmbest,softbits(ns-1))
+call getmetric(4,cmbest,softbits(ns-2))
+if( ns .ge. 6 ) then
+  call getmetric(8,cmbest,softbits(ns-3))
+  call getmetric(16,cmbest,softbits(ns-4))
+  call getmetric(32,cmbest,softbits(ns-5))
+  if( ns .eq. 9 ) then
+    call getmetric(64,cmbest,softbits(3))
+    call getmetric(128,cmbest,softbits(2))
+    call getmetric(256,cmbest,softbits(1))
+  endif
+endif
 end subroutine mskseqdet
 
 subroutine downsample(ci,f0,co)
@@ -260,11 +357,11 @@ subroutine downsample(ci,f0,co)
 
   df=400.0/NI
   ct=ci
-  call four2a(ct,NI,1,-1,1)             !r2c FFT to freq domain
+  call four2a(ct,NI,1,-1,1)             !c2c FFT to freq domain
   i0=nint(f0/df)
   co=0.0
   co(0)=ct(i0)
-  b=4.0
+  b=6.0
   do i=1,NO/2
      arg=(i*df/b)**2
      filt=exp(-arg)
@@ -275,3 +372,133 @@ subroutine downsample(ci,f0,co)
   call four2a(co,NO,1,1,1)            !c2c FFT back to time domain
   return
 end subroutine downsample
+
+subroutine getfc1(c,fs,fa,fb,fc1,xsnr)
+
+!  include 'wsprlf_params.f90'
+  parameter (NZ=288*412)
+  parameter (NSPS=288)
+  parameter (N2=2*NSPS)
+  parameter (NFFT1=16*NSPS)
+  parameter (NH1=NFFT1/2)
+
+  complex c(0:NZ-1)                     !Complex waveform
+  complex c2(0:NFFT1-1)                 !Short spectra
+  real s(-NH1+1:NH1)                    !Coarse spectrum
+  nspec=NZ/N2
+  df1=fs/NFFT1
+  s=0.
+  do k=1,nspec
+     ia=(k-1)*N2
+     ib=ia+N2-1
+     c2(0:N2-1)=c(ia:ib)
+     c2(N2:)=0.
+     call four2a(c2,NFFT1,1,-1,1)
+     do i=0,NFFT1-1
+        j=i
+        if(j.gt.NH1) j=j-NFFT1
+        s(j)=s(j) + real(c2(i))**2 + aimag(c2(i))**2
+     enddo
+  enddo
+!        call smo121(s,NFFT1)
+  smax=0.
+  ipk=0
+  fc1=0.
+  ia=nint(fa/df1)
+  ib=nint(fb/df1)
+  do i=ia,ib
+     f=i*df1
+     if(s(i).gt.smax) then
+        smax=s(i)
+        ipk=i
+        fc1=f
+     endif
+!            write(51,3001) f,s(i),db(s(i))
+! 3001       format(f10.3,e12.3,f10.3)
+  enddo
+
+! The following is for testing SNR calibration:
+  sp3n=(s(ipk-1)+s(ipk)+s(ipk+1))               !Sig + 3*noise
+  base=(sum(s)-sp3n)/(NFFT1-3.0)                !Noise per bin
+  psig=sp3n-3*base                              !Sig only
+  pnoise=(2500.0/df1)*base                      !Noise in 2500 Hz
+  xsnr=db(psig/pnoise)
+  xsnr=xsnr+5.0
+  return
+end subroutine getfc1
+
+subroutine getfc2(c,npeaks,fs,fc1,fpks)
+
+!  include 'wsprlf_params.f90'
+  parameter (NZ=288*412)
+  parameter (NSPS=288)
+  parameter (N2=2*NSPS)
+  parameter (NFFT1=16*NSPS)
+  parameter (NH1=NFFT1/2)
+
+  complex c(0:NZ-1)                     !Complex waveform
+  complex cs(0:NZ-1)                    !For computing spectrum
+  real a(5)
+  real freqs(413),sp2(413),fpks(npeaks)
+  integer pkloc(1)
+
+  df=fs/NZ
+  baud=fs/NSPS
+  a(1)=-fc1
+  a(2:5)=0.
+  call twkfreq1(c,NZ,fs,a,cs)         !Mix down by fc1
+
+! Filter, square, then FFT to get refined carrier frequency fc2.
+  call four2a(cs,NZ,1,-1,1)          !To freq domain
+
+  ia=nint(0.75*baud/df) 
+  cs(ia:NZ-1-ia)=0.                  !Save only freqs around fc1
+!  do i=1,NZ/2
+!    filt=1/(1+((i*df)**2/(0.50*baud)**2)**8)
+!    cs(i)=cs(i)*filt
+!    cs(NZ+1-i)=cs(NZ+1-i)*filt
+!  enddo 
+  call four2a(cs,NZ,1,1,1)           !Back to time domain
+  cs=cs/NZ
+!do i=0,NZ-1
+!write(51,*) i,real(cs(i)),imag(cs(i))
+!enddo
+  cs=cs*cs                           !Square the data
+  call four2a(cs,NZ,1,-1,1)          !Compute squared spectrum
+! Find two peaks separated by baud
+  pmax=0.
+  fc2=0.
+!  ja=nint(0.3*baud/df)
+  ja=nint(0.5*baud/df)
+  k=1
+  sp2=0.0
+  do j=-ja,ja
+     f2=j*df
+     ia=nint((f2-0.5*baud)/df)
+     if(ia.lt.0) ia=ia+NZ
+     ib=nint((f2+0.5*baud)/df)
+     p=real(cs(ia))**2 + aimag(cs(ia))**2 +                        &
+          real(cs(ib))**2 + aimag(cs(ib))**2           
+     if(p.gt.pmax) then
+        pmax=p
+        fc2=0.5*f2
+     endif
+     freqs(k)=0.5*f2
+     sp2(k)=p
+     k=k+1
+!           write(52,1200) f2,p,db(p)
+!1200       format(f10.3,2f15.3)
+  enddo
+
+  do i=1,npeaks
+    pkloc=maxloc(sp2)
+    ipk=pkloc(1)
+    fpks(i)=freqs(ipk)
+    ipk0=max(1,ipk-2)
+    ipk1=min(413,ipk+2)
+!    ipk0=ipk
+!    ipk1=ipk
+    sp2(ipk0:ipk1)=0.0
+  enddo
+  return
+end subroutine getfc2

lib/fsk4hf/wspr5sim.f90

@@ -51,9 +51,9 @@ program wspr5sim
   txt=NN*NSPS0/12000.0
 
   call genwspr5(msg,msgsent,itone)       !Encode the message, get itone
-  write(*,1000) f0,xdt,txt,snrdb,nfiles,msgsent
+  write(*,1000) f0,xdt,txt,snrdb,fspread,delay,nfiles,msgsent
 1000 format('f0:',f9.3,'   DT:',f6.2,'   txt:',f6.1,'   SNR:',f6.1,    &
-          '  nfiles:',i3,2x,a22)
+          '   fspread:',f6.1,'   delay:',f6.1,'  nfiles:',i3,2x,a22)
 
   dphi0=twopi*(f0-0.25*baud)*dt
   dphi1=twopi*(f0+0.25*baud)*dt
@@ -73,19 +73,19 @@ program wspr5sim
      enddo
   enddo
 
-  if( fspread .ne. 0.0 .or. delay .ne. 0.0 ) then
+  call sgran()
-    call watterson(c0,NZ,fs,delay,fspread)
-  endif
-
-  c0=sig*c0                              !Scale to requested sig level
-
   do ifile=1,nfiles
+     c=c0
      if(nwav.eq.0) then
+        if( fspread .ne. 0.0 .or. delay .ne. 0.0 ) then
+           call watterson(c,NZ,fs,delay,fspread)
+        endif
+        c=c*sig
         if(snrdb.lt.90) then
            do i=0,NZ-1                   !Add gaussian noise at specified SNR
               xnoise=gran()
               ynoise=gran()
-              c(i)=c0(i) + cmplx(xnoise,ynoise)
+              c(i)=c(i) + cmplx(xnoise,ynoise)
            enddo
         endif
         write(fname,1100) ifile

lib/fsk4hf/wspr_fsk8_sim.f90

@@ -70,19 +70,19 @@ program wspr_fsk8_sim
      enddo
   enddo
 
-  if( fspread .ne. 0.0 .or. delay .ne. 0.0 ) then
+  call sgran()
-    call watterson(c0,NZ,fs,delay,fspread)
-  endif
-
-  c0=sig*c0                              !Scale to requested sig level
-
   do ifile=1,nfiles
     if(nwav.eq.0) then
+      c=c0
+      if( fspread .ne. 0.0 .or. delay .ne. 0.0 ) then
+        call watterson(c,NZ,fs,delay,fspread)
+      endif
+      c=c*sig
       if( snrdb.lt.90) then
         do i=0,NZ-1
           xnoise=gran()
           ynoise=gran()
-          c(i)=c0(i)+cmplx(xnoise,ynoise)
+          c(i)=c(i)+cmplx(xnoise,ynoise)
         enddo
       endif
       write(fname,1100) ifile