WSJT-X/lib/superfox/sfox_sync.f90
2024-02-22 14:25:17 -05:00

60 lines
1.3 KiB
Fortran

subroutine sfox_sync(crcvd,fsample,f,t)
use sfox_mod
complex crcvd(NMAX) !Signal as received
complex, allocatable :: c(:) !Work array
real, allocatable :: s(:,:) !Symbol spectra, 1/8 symbol steps
! character*1 line(-30:30),mark(0:5)
! data mark/' ','.','-','+','X','$'/
nh=NFFT1/2 !1024
istep=nh/8 !128
nsz=(nint(3.0*fsample) + NS*NSPS)/istep !473
df=fsample/NFFT1 !5.86 Hz
tstep=istep/fsample !0.0107 s
allocate(c(0:nfft1-1))
allocate(s(nh/2,nsz))
ia=1-istep
fac=1.0/NFFT1
do j=1,nsz
ia=ia+istep
ib=ia+nh-1
c(0:NSPS-1)=fac*crcvd(ia:ib)
c(NSPS:)=0.
call four2a(c,NFFT1,1,-1,1)
do i=1,nh/2
s(i,j)=real(c(i))**2 + aimag(c(i))**2
enddo
enddo
pmax=0.
ntol=100
iz=nint(ntol/df)
i0=nint(1500.0/df)
ipk=-999
jpk=-999
do j=1,nsz-8*NS
do i=-iz,iz
p=0.
do k=1,NS
ii=i0+i+(2*(isync(k)-NQ/2))
jj=j + 8*(k-1)
p=p + s(ii,jj)
enddo
if(p.gt.pmax) then
pmax=p
ipk=i
jpk=j
endif
enddo
enddo
dfreq=ipk*df
f=1500.0+dfreq
t=(jpk-201)*istep/fsample
return
end subroutine sfox_sync