mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2025-10-30 20:40:28 -04:00
262 lines
6.7 KiB
Fortran
262 lines
6.7 KiB
Fortran
subroutine ft8c(dd0,newdat,call_1,call_2,grid4,xdt,f1,nharderrors,dmin, &
|
|
msg37,xsnr)
|
|
|
|
use crc
|
|
use timer_module, only: timer
|
|
use packjt77
|
|
include 'ft8_params.f90'
|
|
parameter(NP2=2812)
|
|
character*37 msg37,msg,msgsent,msgbest
|
|
character*12 call_1,call_2
|
|
character*4 grid4
|
|
real a(5)
|
|
real s8(0:7,NN)
|
|
real s2(0:511)
|
|
real bmeta(174),bmetb(174),bmetc(174),bmetd(174)
|
|
real llra(174),llrb(174),llrc(174),llrd(174),llrbest(174) !Soft symbols
|
|
real dd0(15*12000)
|
|
real ss(9)
|
|
real rcw(174)
|
|
integer*1 cw(174)
|
|
integer*1 msgbits(77)
|
|
integer*1 nxor(174),hdec(174)
|
|
integer itone(NN)
|
|
integer icos7(0:6),ip(1)
|
|
logical one(0:511,0:8)
|
|
integer graymap(0:7)
|
|
integer iloc(1)
|
|
complex cd0(0:3199)
|
|
complex ctwk(32)
|
|
complex csymb(32)
|
|
complex cs(0:7,NN)
|
|
logical std_1,std_2
|
|
logical first,newdat
|
|
data icos7/3,1,4,0,6,5,2/ ! Flipped w.r.t. original FT8 sync array
|
|
data first/.true./
|
|
data graymap/0,1,3,2,5,6,4,7/
|
|
save one
|
|
|
|
if(first) then
|
|
one=.false.
|
|
do i=0,511
|
|
do j=0,8
|
|
if(iand(i,2**j).ne.0) one(i,j)=.true.
|
|
enddo
|
|
enddo
|
|
first=.false.
|
|
endif
|
|
|
|
call stdcall(call_1,std_1)
|
|
if(call_1(1:3).eq.'CQ ') std_1=.true.
|
|
call stdcall(call_2,std_2)
|
|
|
|
nharderrors=-1
|
|
fs2=12000.0/NDOWN
|
|
dt2=1.0/fs2
|
|
twopi=8.0*atan(1.0)
|
|
delfbest=0.
|
|
ibest=0
|
|
|
|
call timer('ft8_down',0)
|
|
call ft8_downsample(dd0,newdat,f1,cd0) !Mix f1 to baseband and downsample
|
|
call timer('ft8_down',1)
|
|
|
|
i0=nint((xdt+0.5)*fs2) !Initial guess for start of signal
|
|
smax=0.0
|
|
do idt=i0-10,i0+10 !Search over +/- one quarter symbol
|
|
call sync8d(cd0,idt,ctwk,0,sync)
|
|
if(sync.gt.smax) then
|
|
smax=sync
|
|
ibest=idt
|
|
endif
|
|
enddo
|
|
|
|
! Now peak up in frequency
|
|
smax=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
|
|
a=0.0
|
|
a(1)=-delfbest
|
|
call twkfreq1(cd0,NP2,fs2,a,cd0)
|
|
f1=f1+delfbest !Improved estimate of DF
|
|
|
|
call timer('ft8_down',0)
|
|
call ft8_downsample(dd0,.false.,f1,cd0) !Mix f1 to baseband and downsample
|
|
call timer('ft8_down',1)
|
|
|
|
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 - 0.5
|
|
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) return ! bail out
|
|
|
|
do nsym=1,3
|
|
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
|
|
i1=i/64
|
|
i2=iand(i,63)/8
|
|
i3=iand(i,7)
|
|
if(nsym.eq.1) then
|
|
s2(i)=abs(cs(graymap(i3),ks))
|
|
elseif(nsym.eq.2) then
|
|
s2(i)=abs(cs(graymap(i2),ks)+cs(graymap(i3),ks+1))
|
|
elseif(nsym.eq.3) then
|
|
s2(i)=abs(cs(graymap(i1),ks)+cs(graymap(i2),ks+1)+cs(graymap(i3),ks+2))
|
|
else
|
|
print*,"Error - nsym must be 1, 2, or 3."
|
|
endif
|
|
enddo
|
|
i32=1+(k-1)*3+(ihalf-1)*87
|
|
if(nsym.eq.1) ibmax=2
|
|
if(nsym.eq.2) ibmax=5
|
|
if(nsym.eq.3) ibmax=8
|
|
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
|
|
if(nsym.eq.1) then
|
|
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
|
|
elseif(nsym.eq.2) then
|
|
bmetb(i32+ib)=bm
|
|
elseif(nsym.eq.3) then
|
|
bmetc(i32+ib)=bm
|
|
endif
|
|
enddo
|
|
enddo
|
|
enddo
|
|
enddo
|
|
call normalizebmet(bmeta,174)
|
|
call normalizebmet(bmetb,174)
|
|
call normalizebmet(bmetc,174)
|
|
call normalizebmet(bmetd,174)
|
|
|
|
scalefac=2.83
|
|
llra=scalefac*bmeta
|
|
llrb=scalefac*bmetb
|
|
llrc=scalefac*bmetc
|
|
llrd=scalefac*bmetd
|
|
|
|
! apmag=maxval(abs(llra))*1.01
|
|
|
|
MAXMSG=206
|
|
pbest=0.
|
|
do imsg=1,MAXMSG
|
|
msg=trim(call_1)//' '//trim(call_2)
|
|
i=imsg
|
|
if(call_1(1:3).eq.'CQ ' .and. i.ne.5) msg='QQ0XYZ '//trim(call_2)
|
|
if(.not.std_1) then
|
|
if(i.eq.1 .or. i.ge.6) msg='<'//trim(call_1)//'> '//trim(call_2)
|
|
if(i.ge.2 .and. i.le.4) msg=trim(call_1)//' <'//trim(call_2)//'>'
|
|
else if(.not.std_2) then
|
|
if(i.le.4 .or. i.eq.6) msg='<'//trim(call_1)//'> '//trim(call_2)
|
|
if(i.ge.7) msg=trim(call_1)//' <'//trim(call_2)//'>'
|
|
endif
|
|
j0=len(trim(msg))+2
|
|
if(i.eq.2) msg(j0:j0+2)='RRR'
|
|
if(i.eq.3) msg(j0:j0+3)='RR73'
|
|
if(i.eq.4) msg(j0:j0+1)='73'
|
|
if(i.eq.5) then
|
|
if(std_2) then
|
|
msg='CQ '//trim(call_2)
|
|
if(call_1(3:3).eq.'_') msg=trim(call_1)//' '//trim(call_2)
|
|
if(grid4.ne.'RR73') msg=trim(msg)//' '//grid4
|
|
endif
|
|
if(.not.std_2) msg='CQ '//trim(call_2)
|
|
endif
|
|
if(i.eq.6 .and. std_2) msg(j0:j0+3)=grid4
|
|
if(i.ge.7) then
|
|
isnr = -50 + (i-7)/2
|
|
if(iand(i,1).eq.1) then
|
|
write(msg(j0:j0+2),'(i3.2)') isnr
|
|
if(msg(j0:j0).eq.' ') msg(j0:j0)='+'
|
|
else
|
|
write(msg(j0:j0+3),'("R",i3.2)') isnr
|
|
if(msg(j0+1:j0+1).eq.' ') msg(j0+1:j0+1)='+'
|
|
endif
|
|
endif
|
|
|
|
! Source-encode, then get codeword
|
|
i3=-1
|
|
n3=-1
|
|
call genft8(msg,i3,n3,msgsent,msgbits,itone)
|
|
call encode174_91(msgbits,cw)
|
|
rcw=2*cw-1
|
|
pa=sum(llra*rcw)
|
|
pb=sum(llrb*rcw)
|
|
pc=sum(llrc*rcw)
|
|
pd=sum(llrd*rcw)
|
|
|
|
if(pa.gt.pbest) then
|
|
pbest=pa
|
|
msgbest=msgsent
|
|
llrbest=llra
|
|
nharderrors=count((2*cw-1)*llra.lt.0.0)
|
|
hdec=0
|
|
where(llra.ge.0.0) hdec=1
|
|
nxor=ieor(hdec,cw)
|
|
dmin=sum(nxor*abs(llra))
|
|
endif
|
|
enddo ! imsg
|
|
|
|
! write(*,4001) pbest,nharderrors,dmin,trim(msgbest)
|
|
!4001 format('$$$',f7.1,i4,f7.1,2x,a)
|
|
msg37=msgbest
|
|
|
|
return
|
|
end subroutine ft8c
|