WSJT-X/lib/ft8/ft8b_2.f90
2018-08-29 14:18:56 -04:00

370 lines
10 KiB
Fortran

subroutine ft8b_2(dd0,newdat,nQSOProgress,nfqso,nftx,ndepth,lapon,lapcqonly, &
napwid,lsubtract,nagain,iaptype,mycall12,hiscall12, &
sync0,f1,xdt,xbase,apsym,nharderrors,dmin,nbadcrc,ipass,iera,msg37,xsnr)
use crc
use timer_module, only: timer
use packjt77
include 'ft8_params.f90'
parameter(NP2=2812)
character*37 msg37,msgsent37
character*12 mycall12,hiscall12,hiscall12_0
character*77 c77
character*6 mycall6,hiscall6,c1,c2
character*13 c13
character*87 cbits
real a(5)
real s8(0:7,NN)
real s2(0:511),s2l(0:511)
real bmeta(3*ND),bmetb(3*ND),bmetc(3*ND)
real bmetal(3*ND),bmetbl(3*ND),bmetcl(3*ND)
real llra(3*ND),llrb(3*ND),llrc(3*ND),llrd(3*ND) !Soft symbols
real llral(3*ND),llrbl(3*ND),llrcl(3*ND) !Soft symbols
real dd0(15*12000)
integer*1 message77(77),apmask(3*ND),cw(3*ND)
integer*1 msgbits(77)
integer apsym(77)
integer mcq(29),mrrr(19),m73(19),mrr73(19)
integer itone(NN)
integer icos7(0:6),ip(1)
integer nappasses(0:5) !Number of decoding passes to use for each QSO state
integer naptypes(0:5,4) ! (nQSOProgress, decoding pass) maximum of 4 passes for now
integer*1, target:: i1hiscall(12)
logical one(0:511,0:8)
integer graymap(0:7)
complex cd0(0:3199)
complex ctwk(32)
complex csymb(32)
complex cs(0:7,NN)
logical first,newdat,lsubtract,lapon,lapcqonly,nagain
data icos7/3,1,4,0,6,5,2/ ! Flipped w.r.t. original FT8 sync array
data mcq/0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0/
data mrrr/0,1,1,1,1,1,1,0,1,0,0,1,0,0,1,0,0,0,1/
data m73/0,1,1,1,1,1,1,0,1,0,0,1,0,1,0,0,0,0,1/
data mrr73/0,1,1,1,1,1,1,0,0,1,1,1,0,1,0,1,0,0,1/
data first/.true./
data graymap/0,1,3,2,5,6,4,7/
save nappasses,naptypes,one,hiscall12_0
if(first) then
mcq=2*mcq-1
mrrr=2*mrrr-1
m73=2*m73-1
mrr73=2*mrr73-1
nappasses(0)=2
nappasses(1)=2
nappasses(2)=2
nappasses(3)=4
nappasses(4)=4
nappasses(5)=3
! iaptype
!------------------------
! 1 CQ ??? ??? (29+3=32 ap bits)
! 2 MyCall ??? ??? (29+3=32 ap bits)
! 3 MyCall DxCall ??? (58+3=61 ap bits)
! 4 MyCall DxCall RRR (77 ap bits)
! 5 MyCall DxCall 73 (77 ap bits)
! 6 MyCall DxCall RR73 (77 ap bits)
naptypes(0,1:4)=(/1,2,0,0/)
naptypes(1,1:4)=(/2,3,0,0/)
naptypes(2,1:4)=(/2,3,0,0/)
naptypes(3,1:4)=(/3,4,5,6/)
naptypes(4,1:4)=(/3,4,5,6/)
naptypes(5,1:4)=(/3,1,2,0/)
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
if(hiscall12.ne.hiscall12_0) then
c13=hiscall12//' '
call save_hash_call(c13,n10,n12,n22)
hiscall12_0=hiscall12
endif
max_iterations=30
nharderrors=-1
nbadcrc=1 ! this is used upstream to flag good decodes.
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=i0-8,i0+8 !Search over +/- one quarter symbol
call sync8d(cd0,idt,ctwk,0,2,sync)
if(sync.gt.smax) then
smax=sync
ibest=idt
endif
enddo
xdt2=ibest*dt2 !Improved estimate for DT
! Now peak up in frequency
i0=nint(xdt2*fs2)
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,i0,ctwk,1,2,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)
xdt=xdt2
f1=f1+delfbest !Improved estimate of DF
call sync8d(cd0,i0,ctwk,0,2,sync)
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
return
endif
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
s2l(0:nt-1)=log(s2(0:nt-1)+1e-32)
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))
! bml=maxval(s2l(0:nt-1),one(0:nt-1,ibmax-ib)) - &
! maxval(s2l(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
! bmetal(i32+ib)=bml
elseif(nsym.eq.2) then
bmetb(i32+ib)=bm
! bmetbl(i32+ib)=bml
elseif(nsym.eq.3) then
bmetc(i32+ib)=bm
! bmetcl(i32+ib)=bml
endif
enddo
enddo
enddo
enddo
call normalizebmet(bmeta,3*ND)
! call normalizebmet(bmetal,3*ND)
call normalizebmet(bmetb,3*ND)
! call normalizebmet(bmetbl,3*ND)
call normalizebmet(bmetc,3*ND)
! call normalizebmet(bmetcl,3*ND)
scalefac=2.83
llra=scalefac*bmeta
! llral=scalefac*bmetal
llrb=scalefac*bmetb
! llrbl=scalefac*bmetbl
llrc=scalefac*bmetc
! llrcl=scalefac*bmetcl
apmag=maxval(abs(llrb))*1.01
! pass #
!------------------------------
! 1 regular decoding, nsym=1
! 2 regular decoding, nsym=2
! 3 regular decoding, nsym=3
! 4 ap pass 1, nsym=1 (for now?)
! 5 ap pass 2
! 6 ap pass 3
! 7 ap pass 4
if(lapon) then
if(.not.lapcqonly) then
npasses=3+nappasses(nQSOProgress)
else
npasses=4
endif
else
npasses=3
endif
do ipass=1,npasses
llrd=llra
if(ipass.eq.2) llrd=llrb
if(ipass.eq.3) llrd=llrc
if(ipass.le.3) then
apmask=0
iaptype=0
endif
if(ipass .gt. 3) then
llrd=llra
if(.not.lapcqonly) then
iaptype=naptypes(nQSOProgress,ipass-3)
else
iaptype=1
endif
if(iaptype.ge.3 .and. (abs(f1-nfqso).gt.napwid .and. abs(f1-nftx).gt.napwid) ) cycle
if(iaptype.eq.1 .or. iaptype.eq.2 ) then ! AP,???,???
apmask=0
apmask(1:29)=1
apmask(75:77)=1
llrd(75:77)=apmag*apsym(75:77)
if(iaptype.eq.1) llrd(1:29)=apmag*mcq(1:29)
if(iaptype.eq.2) llrd(1:29)=apmag*apsym(1:29)
endif
if(iaptype.eq.3) then ! mycall, dxcall, ???
apmask=0
apmask(1:56)=1
apmask(75:77)=1
llrd(1:56)=apmag*apsym(1:56)
llrd(75:77)=apmag*apsym(75:77)
endif
if(iaptype.eq.4 .or. iaptype.eq.5 .or. iaptype.eq.6) then
apmask=0
apmask(1:77)=1 ! mycall, hiscall, RRR|73|RR73
llrd(1:58)=apmag*apsym(1:58)
if(iaptype.eq.4) llrd(59:77)=apmag*mrrr
if(iaptype.eq.5) llrd(59:77)=apmag*m73
if(iaptype.eq.6) llrd(59:77)=apmag*mrr73
endif
endif
cw=0
call timer('bpd174_91 ',0)
call bpdecode174_91(llrd,apmask,max_iterations,message77,cw,nharderrors, &
niterations)
call timer('bpd174_91 ',1)
dmin=0.0
if(ndepth.eq.3 .and. nharderrors.lt.0) then
ndeep=3
if(abs(nfqso-f1).le.napwid .or. abs(nftx-f1).le.napwid) then
if((ipass.eq.3 .or. ipass.eq.4) .and. .not.nagain) then
ndeep=3
else
ndeep=4
endif
endif
if(nagain) ndeep=5
call timer('osd174_91 ',0)
call osd174_91(llrd,apmask,ndeep,message77,cw,nharderrors,dmin)
call timer('osd174_91 ',1)
endif
msg37=' '
xsnr=-99.0
if(nharderrors.lt.0 .or. nharderrors.gt.36) cycle
if(count(cw.eq.0).eq.174) cycle !Reject the all-zero codeword
write(c77,'(77i1)') message77
read(c77(72:74),'(b3)') n3
read(c77(75:77),'(b3)') i3
if(i3.gt.4 .or. (i3.eq.0.and.n3.gt.5)) then
cycle
endif
call unpack77(c77,msg37)
if(index(msg37,'QU1RK').gt.0) then
cycle
endif
nbadcrc=0 ! If we get this far: valid codeword, valid (i3,n3), nonquirky message.
call genft8_174_91(msg37,i3,n3,msgsent37,msgbits,itone)
if(lsubtract) call subtractft8(dd0,itone,f1,xdt)
xsig=0.0
xnoi=0.0
do i=1,79
xsig=xsig+s8(itone(i),i)**2
ios=mod(itone(i)+4,7)
xnoi=xnoi+s8(ios,i)**2
enddo
xsnr=0.001
if(xnoi.gt.0 .and. xnoi.lt.xsig) xsnr=xsig/xnoi-1.0
xsnr=10.0*log10(xsnr)-27.0
! need to reconcile signal normalization between this routine and the old ft8b_1 so
! that SNRs come out the same.
xsnr2=db(xsig/xbase - 1.0) - 32.0
! if(.not.nagain) xsnr=xsnr2
if(xsnr .lt. -24.0) xsnr=-24.0
return
enddo
return
end subroutine ft8b_2
! This currently resides in ft8b_1.f90
!subroutine normalizebmet(bmet,n)
! real bmet(n)
!
! bmetav=sum(bmet)/real(n)
! bmet2av=sum(bmet*bmet)/real(n)
! var=bmet2av-bmetav*bmetav
! if( var .gt. 0.0 ) then
! bmetsig=sqrt(var)
! else
! bmetsig=sqrt(bmet2av)
! endif
! bmet=bmet/bmetsig
! return
!end subroutine normalizebmet