subroutine ft8b(dd0,newdat,nQSOProgress,nfqso,nftx,ndepth,lapon,lapcqonly, & napwid,lsubtract,nagain,ncontest,iaptype,f1,xdt,xbase,apsym,nharderrors, & dmin,nbadcrc,ipass,msg37,msgcall,msggrid,xsnr) use crc use packjt77 include 'ft8_params.f90' parameter(NP2=2812) character*37 msg37 character*13 msgcall character*4 msggrid character*77 c77 real a(5) real s8(0:7,NN) real s2(0:511) real bmeta(174),bmetb(174),bmetc(174) real llra(174),llrb(174),llrc(174),llrd(174) !Soft symbols complex dd0(NMAX) integer*1 message77(77),apmask(174),cw(174) integer apsym(58) integer mcq(29),mcqru(29),mcqfd(29),mcqtest(29) integer 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 ncontest,ncontest0 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,unpk77_success 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 mcqru/0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,1,1,1,1,0,0,1,1,0,0/ data mcqfd/0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,1,0,0,1,0,0,0,1,0/ data mcqtest/0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,1,0,1,0,1,1,1,1,1,1,0,0,1,0/ 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,ncontest0,one if(first.or.(ncontest.ne.ncontest0)) then mcq=2*mcq-1 mcqfd=2*mcqfd-1 mcqru=2*mcqru-1 mcqtest=2*mcqtest-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/) ! Tx6 selected (CQ) naptypes(1,1:4)=(/2,3,0,0/) ! Tx1 naptypes(2,1:4)=(/2,3,0,0/) ! Tx2 naptypes(3,1:4)=(/3,4,5,6/) ! Tx3 naptypes(4,1:4)=(/3,4,5,6/) ! Tx4 naptypes(5,1:4)=(/3,1,2,0/) ! Tx5 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. ncontest0=ncontest endif max_iterations=30 nharderrors=-1 nbadcrc=1 ! this is used upstream to flag good decodes. fs2=4000.0/NDOWN dt2=1.0/fs2 twopi=8.0*atan(1.0) delfbest=0. ibest=0 call ft8_downsample(dd0,newdat,f1,cd0) !Mix f1 to baseband and downsample 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,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,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,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 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 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) scalefac=2.83 llra=scalefac*bmeta llrb=scalefac*bmetb llrc=scalefac*bmetc apmag=maxval(abs(llra))*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.or.ncontest.eq.6) then !Hounds always use AP 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 ! ncontest=0 : NONE ! 1 : NA_VHF ! 2 : EU_VHF ! 3 : FIELD DAY ! 4 : RTTY ! 5 : FOX ! 6 : HOUND ! ! Conditions that cause us to bail out of AP decoding if(ncontest.le.4 .and. iaptype.ge.3 .and. (abs(f1-nfqso).gt.napwid .and. abs(f1-nftx).gt.napwid) ) cycle if(ncontest.eq.5) cycle ! No AP for Foxes if(ncontest.eq.6.and.f1.gt.950.0) cycle ! Hounds use AP only for signals below 950 Hz if(iaptype.ge.2 .and. apsym(1).gt.1) cycle ! No, or nonstandard, mycall if(iaptype.ge.3 .and. apsym(30).gt.1) cycle ! No, or nonstandard, dxcall if(iaptype.eq.1) then ! CQ or CQ RU or CQ TEST or CQ FD apmask=0 apmask(1:29)=1 if(ncontest.eq.0) llrd(1:29)=apmag*mcq(1:29) if(ncontest.eq.1) llrd(1:29)=apmag*mcqtest(1:29) if(ncontest.eq.2) llrd(1:29)=apmag*mcqtest(1:29) if(ncontest.eq.3) llrd(1:29)=apmag*mcqfd(1:29) if(ncontest.eq.4) llrd(1:29)=apmag*mcqru(1:29) if(ncontest.eq.6) llrd(1:29)=apmag*mcq(1:29) apmask(75:77)=1 llrd(75:76)=apmag*(-1) llrd(77)=apmag*(+1) endif if(iaptype.eq.2) then ! MyCall,???,??? apmask=0 if(ncontest.eq.0.or.ncontest.eq.1) then apmask(1:29)=1 llrd(1:29)=apmag*apsym(1:29) apmask(75:77)=1 llrd(75:76)=apmag*(-1) llrd(77)=apmag*(+1) else if(ncontest.eq.2) then apmask(1:28)=1 llrd(1:28)=apmag*apsym(1:28) apmask(72:74)=1 llrd(72)=apmag*(-1) llrd(73)=apmag*(+1) llrd(74)=apmag*(-1) apmask(75:77)=1 llrd(75:77)=apmag*(-1) else if(ncontest.eq.3) then apmask(1:28)=1 llrd(1:28)=apmag*apsym(1:28) apmask(75:77)=1 llrd(75:77)=apmag*(-1) else if(ncontest.eq.4) then apmask(2:29)=1 llrd(2:29)=apmag*apsym(1:28) apmask(75:77)=1 llrd(75)=apmag*(-1) llrd(76:77)=apmag*(+1) else if(ncontest.eq.6) then ! ??? RR73; MyCall ??? apmask(29:56)=1 llrd(29:56)=apmag*apsym(1:28) apmask(72:77)=1 llrd(72:73)=apmag*(-1) llrd(74)=apmag*(+1) llrd(75:77)=apmag*(-1) endif endif if(iaptype.eq.3) then ! MyCall,DxCall,??? apmask=0 if(ncontest.eq.0.or.ncontest.eq.1.or.ncontest.eq.2.or.ncontest.eq.6) then apmask(1:58)=1 llrd(1:58)=apmag*apsym apmask(75:77)=1 llrd(75:76)=apmag*(-1) llrd(77)=apmag*(+1) else if(ncontest.eq.3) then ! Field Day apmask(1:56)=1 llrd(1:28)=apmag*apsym(1:28) llrd(29:56)=apmag*apsym(30:57) apmask(72:74)=1 apmask(75:77)=1 llrd(75:77)=apmag*(-1) else if(ncontest.eq.4) then ! RTTY RU apmask(2:57)=1 llrd(2:29)=apmag*apsym(1:28) llrd(30:57)=apmag*apsym(30:57) apmask(75:77)=1 llrd(75)=apmag*(-1) llrd(76:77)=apmag*(+1) endif endif if(iaptype.eq.5.and.ncontest.eq.6) cycle !Hound if(iaptype.eq.4 .or. iaptype.eq.5 .or. iaptype.eq.6) then apmask=0 if(ncontest.le.4 .or. (ncontest.eq.6.and.iaptype.eq.6)) then apmask(1:77)=1 ! mycall, hiscall, RRR|73|RR73 llrd(1:58)=apmag*apsym 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 else if(ncontest.eq.6.and.iaptype.eq.4) then ! Hound listens for MyCall RR73;... apmask(1:28)=1 llrd(1:28)=apmag*apsym(1:28) apmask(72:77)=1 llrd(72:73)=apmag*(-1) llrd(74)=apmag*(1) llrd(75:77)=apmag*(-1) endif endif endif cw=0 call bpdecode174_91(llrd,apmask,max_iterations,message77,cw,nharderrors, & niterations) 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 ndeep=4 endif if(nagain) ndeep=5 call osd174_91(llrd,apmask,ndeep,message77,cw,nharderrors,dmin) endif msg37=' ' 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(c77,1,msg37,msgcall,msggrid,unpk77_success) if(.not.unpk77_success) then cycle endif nbadcrc=0 ! If we get this far: valid codeword, valid (i3,n3), nonquirky message. call get_ft8_tones_from_77bits(message77,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 xsnr2=0.001 arg=xsig/xnoi-1.0 if(arg.gt.0.1) xsnr=arg arg=xsig/xbase/2.6e6-1.0 if(arg.gt.0.1) xsnr2=arg xsnr=10.0*log10(xsnr)-27.0 xsnr2=10.0*log10(xsnr2)-27.0 if(.not.nagain) then xsnr=xsnr2 endif if(xsnr .lt. -24.0) xsnr=-24.0 return enddo return end subroutine ft8b 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 function bessi0(x) ! From Numerical Recipes real bessi0,x double precision p1,p2,p3,p4,p5,p6,p7,q1,q2,q3,q4,q5,q6,q7,q8,q9,y save p1,p2,p3,p4,p5,p6,p7,q1,q2,q3,q4,q5,q6,q7,q8,q9 data p1,p2,p3,p4,p5,p6,p7/1.0d0,3.5156229d0,3.0899424d0,1.2067492d0, & 0.2659732d0,0.360768d-1,0.45813d-2/ data q1,q2,q3,q4,q5,q6,q7,q8,q9/0.39894228d0,0.1328592d-1, & 0.225319d-2,-0.157565d-2,0.916281d-2,-0.2057706d-1, & 0.2635537d-1,-0.1647633d-1,0.392377d-2/ if (abs(x).lt.3.75) then y=(x/3.75)**2 bessi0=p1+y*(p2+y*(p3+y*(p4+y*(p5+y*(p6+y*p7))))) else ax=abs(x) y=3.75/ax bessi0=(exp(ax)/sqrt(ax))*(q1+y*(q2+y*(q3+y*(q4 & +y*(q5+y*(q6+y*(q7+y*(q8+y*q9)))))))) endif return end function bessi0