WSJT-X/lib/setup65.f90

97 lines
2.1 KiB
Fortran

subroutine setup65
! Defines arrays related to the JT65 pseudo-random synchronizing pattern.
! Executed at program start.
use jt65_mod
integer nprc(126)
! JT65
data nprc/ &
1,0,0,1,1,0,0,0,1,1,1,1,1,1,0,1,0,1,0,0, &
0,1,0,1,1,0,0,1,0,0,0,1,1,1,0,0,1,1,1,1, &
0,1,1,0,1,1,1,1,0,0,0,1,1,0,1,0,1,0,1,1, &
0,0,1,1,0,1,0,1,0,1,0,0,1,0,0,0,0,0,0,1, &
1,0,0,0,0,0,0,0,1,1,0,1,0,0,1,0,1,1,0,1, &
0,1,0,1,0,0,1,1,0,0,1,0,0,1,0,0,0,0,1,1, &
1,1,1,1,1,1/
data mr2/0/ !Silence compiler warning
! Put the appropriate pseudo-random sequence into pr
nsym=126
do i=1,nsym
pr(i)=2*nprc(i)-1
enddo
! Determine locations of data and reference symbols
k=0
mr1=0
do i=1,nsym
if(pr(i).lt.0.0) then
k=k+1
mdat(k)=i
else
mr2=i
if(mr1.eq.0) mr1=i
endif
enddo
nsig=k
! Determine the reference symbols for each data symbol.
do k=1,nsig
m=mdat(k)
mref(k,1)=mr1
do n=1,10 !Get ref symbol before data
if((m-n).gt.0) then
if (pr(m-n).gt.0.0) go to 10
endif
enddo
go to 12
10 mref(k,1)=m-n
12 mref(k,2)=mr2
do n=1,10 !Get ref symbol after data
if((m+n).le.nsym) then
if (pr(m+n).gt.0.0) go to 20
endif
enddo
cycle
20 mref(k,2)=m+n
enddo
! Now do it all again, using opposite logic on pr(i)
k=0
mr1=0
do i=1,nsym
if(pr(i).gt.0.0) then
k=k+1
mdat2(k)=i
else
mr2=i
if(mr1.eq.0) mr1=i
endif
enddo
nsig=k
do k=1,nsig
m=mdat2(k)
mref2(k,1)=mr1
do n=1,10
if((m-n).gt.0) then
if (pr(m-n).lt.0.0) go to 110
endif
enddo
go to 112
110 mref2(k,1)=m-n
112 mref2(k,2)=mr2
do n=1,10
if((m+n).le.nsym) then
if (pr(m+n).lt.0.0) go to 120
endif
enddo
cycle
120 mref2(k,2)=m+n
enddo
return
end subroutine setup65