mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-03 07:51:16 -05:00
46e1cd5a30
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7926 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
149 lines
3.9 KiB
Fortran
149 lines
3.9 KiB
Fortran
subroutine sync8(dd,nfa,nfb,syncmin,nfqso,s,candidate,ncand)
|
|
|
|
include 'ft8_params.f90'
|
|
! Search over +/- 1.5s relative to 0.5s TX start time.
|
|
parameter (JZ=38)
|
|
complex cx(0:NH1)
|
|
real s(NH1,NHSYM)
|
|
real savg(NH1)
|
|
real x(NFFT1)
|
|
real sync2d(NH1,-JZ:JZ)
|
|
real red(NH1)
|
|
real candidate0(3,200)
|
|
real candidate(3,200)
|
|
real dd(NMAX)
|
|
integer jpeak(NH1)
|
|
integer indx(NH1)
|
|
integer ii(1)
|
|
integer icos7(0:6)
|
|
data icos7/2,5,6,0,4,1,3/ !Costas 7x7 tone pattern
|
|
equivalence (x,cx)
|
|
|
|
! Compute symbol spectra, stepping by NSTEP steps.
|
|
savg=0.
|
|
tstep=NSTEP/12000.0
|
|
df=12000.0/NFFT1 !3.125 Hz
|
|
fac=1.0/300.0
|
|
do j=1,NHSYM
|
|
ia=(j-1)*NSTEP + 1
|
|
ib=ia+NSPS-1
|
|
x(1:NSPS)=fac*dd(ia:ib)
|
|
x(NSPS+1:)=0.
|
|
call four2a(x,NFFT1,1,-1,0) !r2c FFT
|
|
do i=1,NH1
|
|
s(i,j)=real(cx(i))**2 + aimag(cx(i))**2
|
|
enddo
|
|
savg=savg + s(1:NH1,j) !Average spectrum
|
|
enddo
|
|
savg=savg/NHSYM
|
|
! do i=1,NH1
|
|
! write(51,3051) i*df,savg(i),db(savg(i))
|
|
!3051 format(f10.3,e12.3,f12.3)
|
|
! enddo
|
|
|
|
ia=max(1,nint(nfa/df))
|
|
ib=nint(nfb/df)
|
|
nssy=NSPS/NSTEP ! # steps per symbol
|
|
nfos=NFFT1/NSPS ! # frequency bin oversampling factor
|
|
jstrt=0.5/tstep
|
|
|
|
do i=ia,ib
|
|
do j=-JZ,+JZ
|
|
ta=0.
|
|
tb=0.
|
|
tc=0.
|
|
t0a=0.
|
|
t0b=0.
|
|
t0c=0.
|
|
do n=0,6
|
|
k=j+jstrt+nssy*n
|
|
if(k.ge.1.and.k.le.NHSYM) then
|
|
ta=ta + s(i+nfos*icos7(n),k)
|
|
t0a=t0a + sum(s(i:i+nfos*6:nfos,k))
|
|
endif
|
|
tb=tb + s(i+nfos*icos7(n),k+nssy*36)
|
|
t0b=t0b + sum(s(i:i+nfos*6:nfos,k+nssy*36))
|
|
if(k+nssy*72.le.NHSYM) then
|
|
tc=tc + s(i+nfos*icos7(n),k+nssy*72)
|
|
t0c=t0c + sum(s(i:i+nfos*6:nfos,k+nssy*72))
|
|
endif
|
|
enddo
|
|
t=ta+tb+tc
|
|
t0=t0a+t0b+t0c
|
|
t0=(t0-t)/6.0
|
|
sync_abc=t/t0
|
|
|
|
t=tb+tc
|
|
t0=t0b+t0c
|
|
t0=(t0-t)/6.0
|
|
sync_bc=t/t0
|
|
sync2d(i,j)=max(sync_abc,sync_bc)
|
|
enddo
|
|
enddo
|
|
|
|
red=0.
|
|
do i=ia,ib
|
|
ii=maxloc(sync2d(i,-JZ:JZ)) - 1 - JZ
|
|
j0=ii(1)
|
|
jpeak(i)=j0
|
|
red(i)=sync2d(i,j0)
|
|
! write(52,3052) i*df,red(i),db(red(i))
|
|
!3052 format(3f12.3)
|
|
enddo
|
|
iz=ib-ia+1
|
|
call indexx(red(ia:ib),iz,indx)
|
|
ibase=indx(nint(0.40*iz)) - 1 + ia
|
|
base=red(ibase)
|
|
red=red/base
|
|
|
|
candidate0=0.
|
|
k=0
|
|
do i=1,200
|
|
n=ia + indx(iz+1-i) - 1
|
|
if(red(n).lt.syncmin) exit
|
|
if(k.lt.200) k=k+1
|
|
candidate0(1,k)=n*df
|
|
candidate0(2,k)=(jpeak(n)-1)*tstep
|
|
candidate0(3,k)=red(n)
|
|
enddo
|
|
ncand=k
|
|
|
|
! Put nfqso at top of list, and save only the best of near-dupe freqs.
|
|
do i=1,ncand
|
|
if(abs(candidate0(1,i)-nfqso).lt.10.0) candidate0(1,i)=-candidate0(1,i)
|
|
if(i.ge.2) then
|
|
do j=1,i-1
|
|
fdiff=abs(candidate0(1,i))-abs(candidate0(1,j))
|
|
if(abs(fdiff).lt.4.0) then
|
|
if(candidate0(3,i).ge.candidate0(3,j)) candidate0(3,j)=0.
|
|
if(candidate0(3,i).lt.candidate0(3,j)) candidate0(3,i)=0.
|
|
endif
|
|
enddo
|
|
! write(*,3001) i,candidate0(1,i-1),candidate0(1,i),candidate0(3,i-1), &
|
|
! candidate0(3,i)
|
|
!3001 format(i2,4f8.1)
|
|
endif
|
|
enddo
|
|
|
|
fac=20.0/maxval(s)
|
|
s=fac*s
|
|
|
|
! Sort by sync
|
|
! call indexx(candidate0(3,1:ncand),ncand,indx)
|
|
! Sort by frequency
|
|
call indexx(candidate0(1,1:ncand),ncand,indx)
|
|
k=1
|
|
! do i=ncand,1,-1
|
|
do i=1,ncand
|
|
j=indx(i)
|
|
if( candidate0(3,j) .ge. syncmin .and. candidate0(2,j).ge.-1.5 ) then
|
|
candidate(1,k)=abs(candidate0(1,j))
|
|
candidate(2,k)=candidate0(2,j)
|
|
candidate(3,k)=candidate0(3,j)
|
|
k=k+1
|
|
endif
|
|
enddo
|
|
ncand=k-1
|
|
return
|
|
end subroutine sync8
|