mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-06 01:11:18 -05:00
46 lines
1.1 KiB
Fortran
46 lines
1.1 KiB
Fortran
|
subroutine ccf2(ss,nz,nflip,ccfbest,lagpk)
|
||
|
|
|
||
|
|
! parameter (LAGMAX=60)
|
||
|
|
parameter (LAGMAX=200)
|
||
|
|
real ss(nz)
|
||
|
|
real ccf(-LAGMAX:LAGMAX)
|
||
|
|
integer npr(126)
|
||
|
|
|
||
|
|
! The JT65 pseudo-random sync pattern:
|
||
|
|
data npr/ &
|
||
|
|
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/
|
||
|
|
save
|
||
|
|
|
||
|
|
ccfbest=0.
|
||
|
|
lag1=-LAGMAX
|
||
|
|
lag2=LAGMAX
|
||
|
|
do lag=lag1,lag2
|
||
|
|
s0=0.
|
||
|
|
s1=0.
|
||
|
|
do i=1,126
|
||
|
|
j=2*(8*i + 43) + lag
|
||
|
|
if(j.ge.1 .and. j.le.nz-8) then
|
||
|
|
x=ss(j)+ss(j+8) !Add two half-symbol contributions
|
||
|
|
if(npr(i).eq.0) then
|
||
|
|
s0=s0 + x
|
||
|
|
else
|
||
|
|
s1=s1 + x
|
||
|
|
endif
|
||
|
|
endif
|
||
|
|
enddo
|
||
|
|
ccf(lag)=nflip*(s1-s0)
|
||
|
|
if(ccf(lag).gt.ccfbest) then
|
||
|
|
ccfbest=ccf(lag)
|
||
|
|
lagpk=lag
|
||
|
|
endif
|
||
|
|
enddo
|
||
|
|
|
||
|
|
return
|
||
|
|
end subroutine ccf2
|