mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-05 00:41:19 -05:00
6dcdee836e
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7144 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
51 lines
1.2 KiB
Fortran
51 lines
1.2 KiB
Fortran
subroutine msk144_freq_search(cdat,fc,if1,if2,delf,nframes,navmask,cb, &
|
|
cdat2,xmax,bestf,cs,xccs)
|
|
|
|
parameter (NSPM=864,NZ=7*NSPM)
|
|
complex cdat(NZ)
|
|
complex cdat2(NZ)
|
|
complex c(NSPM) !Coherently averaged complex data
|
|
complex ct2(2*NSPM)
|
|
complex cs(NSPM)
|
|
complex cb(42) !Complex waveform for sync word
|
|
complex cc(0:NSPM-1)
|
|
real xcc(0:NSPM-1)
|
|
real xccs(0:NSPM-1)
|
|
integer navmask(nframes) !Tells which frames to average
|
|
|
|
navg=sum(navmask)
|
|
n=nframes*NSPM
|
|
fac=1.0/(48.0*sqrt(float(navg)))
|
|
|
|
do ifr=if1,if2 !Find freq that maximizes sync
|
|
ferr=ifr*delf
|
|
call tweak1(cdat,n,-(fc+ferr),cdat2)
|
|
c=0
|
|
sumw=0.
|
|
do i=1,nframes
|
|
ib=(i-1)*NSPM+1
|
|
ie=ib+NSPM-1
|
|
if(navmask(i).eq.1) c=c + cdat2(ib:ie)
|
|
enddo
|
|
|
|
cc=0
|
|
ct2(1:NSPM)=c
|
|
ct2(NSPM+1:2*NSPM)=c
|
|
|
|
do ish=0,NSPM-1
|
|
cc(ish)=dot_product(ct2(1+ish:42+ish)+ct2(337+ish:378+ish),cb(1:42))
|
|
enddo
|
|
|
|
xcc=abs(cc)
|
|
xb=maxval(xcc)*fac
|
|
if(xb.gt.xmax) then
|
|
xmax=xb
|
|
bestf=ferr
|
|
cs=c
|
|
xccs=xcc
|
|
endif
|
|
enddo
|
|
|
|
return
|
|
end subroutine msk144_freq_search
|