mirror of https://github.com/saitohirga/WSJT-X.git
56 lines
1.0 KiB
Fortran
56 lines
1.0 KiB
Fortran
subroutine sync9f(s2,nq,nfa,nfb,ss2,ss3,lagpk,ipk,ccfbest)
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! Look for JT9 sync pattern in the folded symbol spectra, s2.
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! Frequency search extends from nfa to nfb. Synchronized symbol
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! spectra are put into ss2() and ss3().
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integer ii4(16)
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real s2(240,340)
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real ss2(0:8,85)
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real ss3(0:7,69)
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include 'jt9sync.f90'
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ii4=4*ii-3
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ccf=0.
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ccfbest=0.
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nfft=4*nq
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df=12000.0/nfft
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ia=nfa/df
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ib=nfb/df + 0.9999
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do i=ia,ib
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do lag=0,339
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t=0.
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do n=1,16
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j=ii4(n)+lag
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if(j.gt.340) j=j-340
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t=t + s2(i,j)
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enddo
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if(t.gt.ccfbest) then
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lagpk=lag
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ipk=i
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ccfbest=t
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endif
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enddo
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enddo
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do i=0,8
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j4=lagpk-4
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i2=2*i + ipk
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if(i2.lt.1) i2=1
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m=0
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do j=1,85
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j4=j4+4
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if(j4.gt.340) j4=j4-340
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if(j4.lt.1) j4=j4+340
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ss2(i,j)=s2(i2,j4)
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if(i.ge.1 .and. isync(j).eq.0) then
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m=m+1
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ss3(i-1,m)=ss2(i,j)
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endif
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enddo
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enddo
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return
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end subroutine sync9f
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