WSJT-X/lib/spec9.f90
Joe Taylor 7369062c4a Rename library directory
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@2635 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
2012-10-03 14:31:43 +00:00

95 lines
2.1 KiB
Fortran

subroutine spec9(c0,npts8,nsps,f0a,lagpk,fpk,i1SoftSymbols)
parameter (MAXFFT=31500)
complex c0(0:npts8-1)
real s(0:MAXFFT-1)
real ssym(0:8,184)
real ssymg(0:8,184)
complex c(0:MAXFFT-1)
integer*1 i1SoftSymbolsScrambled(207)
integer*1 i1SoftSymbols(207)
integer ibit(207)
integer*1 t1(13) !72 bits and zero tail as 8-bit bytes
integer*4 t4(69) !Symbols from t5, values 0-7
integer*4 mettab(0:255,0:1)
integer*1 tmp(72)
character*22 msg
integer isync(85)
integer ii(16) !Locations of sync symbols
data ii/1,6,11,16,21,26,31,39,45,51,57,63,69,75,81,85/
integer ig(0:7)
data ig/0,1,3,2,7,6,4,5/
! data ig/0,1,3,2,6,7,5,4/
isync=0
do i=1,16
isync(ii(i))=1
enddo
idt=-400
idf=0.
fshift=fpk-f0a + 0.1*idf
twopi=8.0*atan(1.0)
dphi=twopi*fshift/1500.0
nsps8=nsps/8
nfft=nsps8
df=1500.0/nfft
s=0.
istart=lagpk*nsps8 + idt
nsym=min((npts8-istart)/nsps8,85)
do j=0,nsym-1
ia=j*nsps8 + istart
ib=ia+nsps8-1
c(0:nfft-1)=c0(ia:ib)
phi=0.
do i=0,nfft-1
phi=phi + dphi
c(i)=c(i) * cmplx(cos(phi),-sin(phi))
enddo
call four2a(c,nfft,1,-1,1)
do i=0,nfft-1
sx=real(c(i))**2 + aimag(c(i))**2
if(i.le.8) ssym(i,1+j)=sx
s(i)=s(i) + sx
enddo
enddo
ssymg=ssym
do j=1,nsym
ssym(0,j)=ssymg(0,j)
do i=0,7
ssym(ig(i)+1,j)=ssymg(i+1,j)
enddo
enddo
m0=3
ntones=8
k=0
do j=1,nsym
if(isync(j).eq.1) cycle
do m=m0-1,0,-1 !Get bit-wise soft symbols
n=2**m
r1=0.
r2=0.
do i=0,ntones-1
if(iand(i,n).ne.0) then
r1=max(r1,ssym(i+1,j))
else
r2=max(r2,ssym(i+1,j))
endif
enddo
k=k+1
i1SoftSymbolsScrambled(k)=min(127,max(-127,nint(10.0*(r1-r2)))) + 128
enddo
enddo
call interleave9(i1SoftSymbolsScrambled,-1,i1SoftSymbols)
return
end subroutine spec9