WSJT-X/lib/superfox/sfox_remove_ft8.f90

214 lines
5.2 KiB
Fortran

subroutine sfox_remove_ft8(dd,npts)
use packjt77
include 'ft8_params.f90'
parameter (MAXCAND=100)
parameter (NP2=2812)
integer itone(NN)
integer iloc(1), ip(1)
integer icos7(0:6)
integer graymap(0:7)
integer*1 cw(174),apmask(174)
integer*1 message91(91)
integer*1 message77(77)
character*77 c77
character*37 msg37
real s8(0:7,NN)
real s2(0:7)
real ss(9)
real candidate(3,MAXCAND)
real sbase(NH1)
real dd(npts)
real bmeta(174),bmetd(174)
real llra(174),llrd(174)
complex cd0(0:3199)
complex csymb(32)
complex ctwk(32)
complex cs(0:7,NN)
data icos7/3,1,4,0,6,5,2/
logical first,newdat
logical one(0:7,0:2)
logical unpk77_success
data first/.true./
data graymap/0,1,3,2,5,6,4,7/
save one,first,twopi
if(first) then
one=.false.
do i=0,7
do j=0,2
if(iand(i,2**j).ne.0) one(i,j)=.true.
enddo
enddo
first=.false.
twopi=8.0*atan(1.0)
endif
fs2=12000.0/NDOWN
dt2=1.0/fs2
nfa=500
nfb=2500
syncmin=1.5
nfqso=750
call sync8(dd,npts,nfa,nfb,syncmin,nfqso,MAXCAND,candidate,ncand,sbase)
newdat=.true.
do icand=1,ncand
f1=candidate(1,icand)
xdt=candidate(2,icand)
xbase=10.0**(0.1*(sbase(nint(f1/3.125))-40.0))
call ft8_downsample(dd,newdat,f1,cd0)
newdat=.false.
i0=nint((xdt+0.5)*fs2)
smax=0.0
do idt=i0-10,i0+10
call sync8d(cd0,idt,ctwk,0,sync)
if(sync.gt.smax) then
smax=sync
ibest=idt
endif
enddo
smax=0.0
delfbest=0.0
do ifr=-5,5 !Search over +/- 2.5 Hz
delf=ifr*0.5
dphi=twopi*delf*dt2
phi=0.0
do i=1,32
ctwk(i)=cmplx(cos(phi),sin(phi))
phi=mod(phi+dphi,twopi)
enddo
call sync8d(cd0,ibest,ctwk,1,sync)
if( sync .gt. smax ) then
smax=sync
delfbest=delf
endif
enddo
f1=f1+delfbest !Improved estimate of DF
call ft8_downsample(dd,newdat,f1,cd0) !Mix f1 to baseband and downsample
smax=0.0
do idt=-4,4 !Search over +/- one quarter symbol
call sync8d(cd0,ibest+idt,ctwk,0,sync)
ss(idt+5)=sync
enddo
smax=maxval(ss)
iloc=maxloc(ss)
ibest=iloc(1)-5+ibest
xdt=(ibest-1)*dt2
sync=smax
do k=1,NN
i1=ibest+(k-1)*32
csymb=cmplx(0.0,0.0)
if( i1.ge.0 .and. i1+31 .le. NP2-1 ) csymb=cd0(i1:i1+31)
call four2a(csymb,32,1,-1,1)
cs(0:7,k)=csymb(1:8)/1e3
s8(0:7,k)=abs(csymb(1:8))
enddo
! sync quality check
is1=0
is2=0
is3=0
do k=1,7
ip=maxloc(s8(:,k))
if(icos7(k-1).eq.(ip(1)-1)) is1=is1+1
ip=maxloc(s8(:,k+36))
if(icos7(k-1).eq.(ip(1)-1)) is2=is2+1
ip=maxloc(s8(:,k+72))
if(icos7(k-1).eq.(ip(1)-1)) is3=is3+1
enddo
! hard sync sum - max is 21
nsync=is1+is2+is3
if(nsync .le. 6) then ! bail out
nbadcrc=1
cycle
endif
nsym=1
nt=2**(3*nsym)
do ihalf=1,2
do k=1,29,nsym
if(ihalf.eq.1) ks=k+7
if(ihalf.eq.2) ks=k+43
amax=-1.0
do i=0,nt-1
i3=iand(i,7)
s2(i)=abs(cs(graymap(i3),ks))
enddo
i32=1+(k-1)*3+(ihalf-1)*87
ibmax=2
do ib=0,ibmax
bm=maxval(s2(0:nt-1),one(0:nt-1,ibmax-ib)) - &
maxval(s2(0:nt-1),.not.one(0:nt-1,ibmax-ib))
if(i32+ib .gt.174) cycle
bmeta(i32+ib)=bm
den=max(maxval(s2(0:nt-1),one(0:nt-1,ibmax-ib)), &
maxval(s2(0:nt-1),.not.one(0:nt-1,ibmax-ib)))
if(den.gt.0.0) then
cm=bm/den
else ! erase it
cm=0.0
endif
bmetd(i32+ib)=cm
enddo
enddo
enddo
call normalizebmet(bmeta,174)
call normalizebmet(bmetd,174)
scalefac=2.83
llra=scalefac*bmeta
llrd=scalefac*bmetd
cw=0
dmin=0
norder=2
maxosd=-1
Keff=91
apmask=0
message91=0
cw=0
call decode174_91(llra,Keff,maxosd,norder,apmask,message91,cw, &
ntype,nharderrors,dmin)
if(nharderrors.ge.0) then
message77=message91(1:77)
else
cycle
endif
if(count(cw.eq.0).eq.174) cycle
write(c77,'(77i1)') message77
read(c77(72:74),'(b3)') n3
read(c77(75:77),'(b3)') i3
if(i3.gt.5 .or. (i3.eq.0.and.n3.gt.6)) cycle
if(i3.eq.0 .and. n3.eq.2) cycle
call unpack77(c77,1,msg37,unpk77_success)
! write(77,*) 'FT8 interference: ',msg37
if(.not.unpk77_success) cycle
! Message structure: S7 D29 S7 D29 S7
itone(1:7)=icos7
itone(36+1:36+7)=icos7
itone(NN-6:NN)=icos7
k=7
do j=1,ND
i=3*j -2
k=k+1
if(j.eq.30) k=k+7
indx=cw(i)*4 + cw(i+1)*2 + cw(i+2)
itone(k)=graymap(indx)
enddo
call subtractft8(dd,itone,f1,xdt,.true.)
! return
enddo
return
end subroutine sfox_remove_ft8