subroutine ft4_decode(cdatetime0,tbuf,nfa,nfb,nQSOProgress,ncontest,nfqso, & iwave,ndecodes,mycall,hiscall,cqstr,line,data_dir) use packjt77 include 'ft4_params.f90' parameter (NSS=NSPS/NDOWN) character message*37,msgsent*37,msg0*37 character c77*77 character*61 line,linex(100) character*37 decodes(100) character*512 data_dir,fname character*17 cdatetime0 character*12 mycall,hiscall character*12 mycall0,hiscall0 character*6 hhmmss character*4 cqstr,cqstr0 complex cd2(0:NMAX/NDOWN-1) !Complex waveform complex cb(0:NMAX/NDOWN-1) complex cd(0:NN*NSS-1) !Complex waveform complex ctwk(4*NSS),ctwk2(4*NSS) complex csymb(NSS) complex cs(0:3,NN) real s4(0:3,NN) real bmeta(2*NN),bmetb(2*NN),bmetc(2*NN) real a(5) real llr(2*ND),llra(2*ND),llrb(2*ND),llrc(2*ND),llrd(2*ND) real s2(0:255) real candidate(3,100) real savg(NH1),sbase(NH1) integer apbits(2*ND) integer apmy_ru(28),aphis_fd(28) integer icos4a(0:3),icos4b(0:3),icos4c(0:3),icos4d(0:3) integer*2 iwave(NMAX) !Raw received data integer*1 message77(77),rvec(77),apmask(2*ND),cw(2*ND) integer*1 hbits(2*NN) integer graymap(0:3) integer ip(1) integer nappasses(0:5) ! # of decoding passes for QSO States 0-5 integer naptypes(0:5,4) ! nQSOProgress, decoding pass integer mcq(29) integer mrrr(19),m73(19),mrr73(19) logical nohiscall,unpk77_success logical one(0:255,0:7) ! 256 4-symbol sequences, 8 bits logical first data icos4a/0,1,3,2/ data icos4b/1,0,2,3/ data icos4c/2,3,1,0/ data icos4d/3,2,0,1/ data graymap/0,1,3,2/ data msg0/' '/ data first/.true./ 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 rvec/0,1,0,0,1,0,1,0,0,1,0,1,1,1,1,0,1,0,0,0,1,0,0,1,1,0,1,1,0, & 1,0,0,1,0,1,1,0,0,0,0,1,0,0,0,1,0,1,0,0,1,1,1,1,0,0,1,0,1, & 0,1,0,1,0,1,1,0,1,1,1,1,1,0,0,0,1,0,1/ save fs,dt,tt,txt,twopi,h,one,first,linex,apbits,nappasses,naptypes, & mycall0,hiscall0,msg0,cqstr0 call clockit('ft4_deco',0) hhmmss=cdatetime0(8:13) if(first) then fs=12000.0/NDOWN !Sample rate after downsampling dt=1/fs !Sample interval after downsample (s) tt=NSPS*dt !Duration of "itone" symbols (s) txt=NZ*dt !Transmission length (s) without ramp up/down twopi=8.0*atan(1.0) h=1.0 one=.false. do i=0,255 do j=0,7 if(iand(i,2**j).ne.0) one(i,j)=.true. enddo enddo mrrr=2*mod(mrrr+rvec(59:77),2)-1 m73=2*mod(m73+rvec(59:77),2)-1 mrr73=2*mod(mrr73+rvec(59:77),2)-1 nappasses(0)=2 nappasses(1)=2 nappasses(2)=2 nappasses(3)=2 nappasses(4)=2 nappasses(5)=3 ! iaptype !------------------------ ! 1 CQ ??? ??? (29 ap bits) ! 2 MyCall ??? ??? (29 ap bits) ! 3 MyCall DxCall ??? (58 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)=(/3,6,0,0/) ! Tx3 naptypes(4,1:4)=(/3,6,0,0/) ! Tx4 naptypes(5,1:4)=(/3,1,2,0/) ! Tx5 mycall0='' hiscall0='' cqstr0='' first=.false. endif if(cqstr.ne.cqstr0) then i0=index(cqstr,' ') if(i0.le.1) then message='CQ A1AA AA01' else message='CQ '//cqstr(1:i0-1)//' A1AA AA01' endif i3=-1 n3=-1 call pack77(message,i3,n3,c77) call unpack77(c77,1,msgsent,unpk77_success) read(c77,'(29i1)') mcq mcq=2*mod(mcq+rvec(1:29),2)-1 cqstr0=cqstr endif l1=index(mycall,char(0)) if(l1.ne.0) mycall(l1:)=" " l1=index(hiscall,char(0)) if(l1.ne.0) hiscall(l1:)=" " if(mycall.ne.mycall0 .or. hiscall.ne.hiscall0) then apbits=0 apbits(1)=99 apbits(30)=99 apmy_ru=0 aphis_fd=0 if(len(trim(mycall)) .lt. 3) go to 10 nohiscall=.false. hiscall0=hiscall if(len(trim(hiscall0)).lt.3) then hiscall0=mycall ! use mycall for dummy hiscall - mycall won't be hashed. nohiscall=.true. endif message=trim(mycall)//' '//trim(hiscall0)//' RR73' i3=-1 n3=-1 call pack77(message,i3,n3,c77) call unpack77(c77,1,msgsent,unpk77_success) if(i3.ne.1 .or. (message.ne.msgsent) .or. .not.unpk77_success) go to 10 read(c77,'(77i1)') message77 apmy_ru=2*mod(message77(1:28)+rvec(2:29),2)-1 aphis_fd=2*mod(message77(30:57)+rvec(29:56),2)-1 message77=mod(message77+rvec,2) call encode174_91(message77,cw) apbits=2*cw-1 if(nohiscall) apbits(30)=99 10 continue mycall0=mycall hiscall0=hiscall endif candidate=0.0 ncand=0 syncmin=1.2 maxcand=100 fa=nfa fb=nfb call clockit('getcand4',0) call getcandidates4(iwave,fa,fb,syncmin,nfqso,maxcand,savg,candidate, & ncand,sbase) call clockit('getcand4',1) ndecodes=0 do icand=1,ncand f0=candidate(1,icand) if(f0.le.max(fa,10.0) .or. f0.ge.min(fb,4990.0)) cycle snr=candidate(3,icand)-1.0 call clockit('ft4_down',0) call ft4_downsample(iwave,f0,cd2) !Downsample from 512 to 32 Sa/Symbol call clockit('ft4_down',1) sum2=sum(cd2*conjg(cd2))/(real(NMAX)/real(NDOWN)) if(sum2.gt.0.0) cd2=cd2/sqrt(sum2) ! Sample rate is now 12000/16 = 750 samples/second do isync=1,2 if(isync.eq.1) then idfmin=-12 idfmax=12 idfstp=3 ibmin=0 ibmax=216 !Max DT = 216/750 = 0.288 s ibstp=4 else idfmin=idfbest-4 idfmax=idfbest+4 idfstp=1 ibmin=max(0,ibest-5) ibmax=min(ibest+5,NMAX/NDOWN-1) ibstp=1 endif ibest=-1 smax=-99. idfbest=0 do idf=idfmin,idfmax,idfstp a=0. a(1)=real(idf) ctwk=1. call clockit('twkfreq1',0) call twkfreq1(ctwk,4*NSS,fs,a,ctwk2) call clockit('twkfreq1',1) call clockit('sync4d ',0) do istart=ibmin,ibmax,ibstp call sync4d(cd2,istart,ctwk2,1,sync,sync2) !Find sync power if(sync.gt.smax) then smax=sync ibest=istart idfbest=idf endif enddo call clockit('sync4d ',1) enddo enddo f0=f0+real(idfbest) if( f0.le.10.0 .or. f0.ge.4990.0 ) cycle call clockit('ft4down ',0) call ft4_downsample(iwave,f0,cb) !Final downsample with corrected f0 call clockit('ft4down ',1) sum2=sum(abs(cb)**2)/(real(NSS)*NN) if(sum2.gt.0.0) cb=cb/sqrt(sum2) cd=cb(ibest:ibest+NN*NSS-1) call clockit('four2a ',0) do k=1,NN i1=(k-1)*NSS csymb=cd(i1:i1+NSS-1) call four2a(csymb,NSS,1,-1,1) cs(0:3,k)=csymb(1:4) s4(0:3,k)=abs(csymb(1:4)) enddo call clockit('four2a ',1) ! Sync quality check is1=0 is2=0 is3=0 is4=0 do k=1,4 ip=maxloc(s4(:,k)) if(icos4a(k-1).eq.(ip(1)-1)) is1=is1+1 ip=maxloc(s4(:,k+33)) if(icos4b(k-1).eq.(ip(1)-1)) is2=is2+1 ip=maxloc(s4(:,k+66)) if(icos4c(k-1).eq.(ip(1)-1)) is3=is3+1 ip=maxloc(s4(:,k+99)) if(icos4d(k-1).eq.(ip(1)-1)) is4=is4+1 enddo nsync=is1+is2+is3+is4 !Number of correct hard sync symbols, 0-16 if(smax .lt. 0.7 .or. nsync .lt. 8) cycle do nseq=1,3 !Try coherent sequences of 1, 2, and 4 symbols if(nseq.eq.1) nsym=1 if(nseq.eq.2) nsym=2 if(nseq.eq.3) nsym=4 nt=2**(2*nsym) do ks=1,NN-nsym+1,nsym !87+16=103 symbols. amax=-1.0 do i=0,nt-1 i1=i/64 i2=iand(i,63)/16 i3=iand(i,15)/4 i4=iand(i,3) if(nsym.eq.1) then s2(i)=abs(cs(graymap(i4),ks)) elseif(nsym.eq.2) then s2(i)=abs(cs(graymap(i3),ks)+cs(graymap(i4),ks+1)) elseif(nsym.eq.4) then s2(i)=abs(cs(graymap(i1),ks ) + & cs(graymap(i2),ks+1) + & cs(graymap(i3),ks+2) + & cs(graymap(i4),ks+3) & ) else print*,"Error - nsym must be 1, 2, or 4." endif enddo ipt=1+(ks-1)*2 if(nsym.eq.1) ibmax=1 if(nsym.eq.2) ibmax=3 if(nsym.eq.4) ibmax=7 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(ipt+ib.gt.2*NN) cycle if(nsym.eq.1) then bmeta(ipt+ib)=bm elseif(nsym.eq.2) then bmetb(ipt+ib)=bm elseif(nsym.eq.4) then bmetc(ipt+ib)=bm endif enddo enddo enddo bmetb(205:206)=bmeta(205:206) bmetc(201:204)=bmetb(201:204) bmetc(205:206)=bmeta(205:206) call clockit('normaliz',0) call normalizebmet(bmeta,2*NN) call normalizebmet(bmetb,2*NN) call normalizebmet(bmetc,2*NN) call clockit('normaliz',1) hbits=0 where(bmeta.ge.0) hbits=1 ns1=count(hbits( 1: 8).eq.(/0,0,0,1,1,0,1,1/)) ns2=count(hbits( 67: 74).eq.(/0,1,0,0,1,1,1,0/)) ns3=count(hbits(133:140).eq.(/1,1,1,0,0,1,0,0/)) ns4=count(hbits(199:206).eq.(/1,0,1,1,0,0,0,1/)) nsync_qual=ns1+ns2+ns3+ns4 if(nsync_qual.lt. 20) cycle scalefac=2.83 llra( 1: 58)=bmeta( 9: 66) llra( 59:116)=bmeta( 75:132) llra(117:174)=bmeta(141:198) llra=scalefac*llra llrb( 1: 58)=bmetb( 9: 66) llrb( 59:116)=bmetb( 75:132) llrb(117:174)=bmetb(141:198) llrb=scalefac*llrb llrc( 1: 58)=bmetc( 9: 66) llrc( 59:116)=bmetc( 75:132) llrc(117:174)=bmetc(141:198) llrc=scalefac*llrc apmag=maxval(abs(llra))*1.1 npasses=3+nappasses(nQSOProgress) if(ncontest.ge.5) npasses=3 ! Don't support Fox and Hound do ipass=1,npasses if(ipass.eq.1) llr=llra if(ipass.eq.2) llr=llrb if(ipass.eq.3) llr=llrc if(ipass.le.3) then apmask=0 iaptype=0 endif if(ipass .gt. 3) then llrd=llrc iaptype=naptypes(nQSOProgress,ipass-3) ! 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 napwid=50 if(ncontest.le.4 .and. iaptype.ge.3 .and. (abs(f0-nfqso).gt.napwid) ) cycle if(iaptype.ge.2 .and. apbits(1).gt.1) cycle ! No, or nonstandard, mycall if(iaptype.ge.3 .and. apbits(30).gt.1) cycle ! No, or nonstandard, dxcall if(iaptype.eq.1) then ! CQ or CQ TEST or CQ FD or CQ RU or CQ SCC apmask=0 apmask(1:29)=1 llrd(1:29)=apmag*mcq(1:29) 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*apbits(1:29) else if(ncontest.eq.2) then apmask(1:28)=1 llrd(1:28)=apmag*apbits(1:28) else if(ncontest.eq.3) then apmask(1:28)=1 llrd(1:28)=apmag*apbits(1:28) else if(ncontest.eq.4) then apmask(2:29)=1 llrd(2:29)=apmag*apmy_ru(1:28) endif endif if(iaptype.eq.3) then ! MyCall,DxCall,??? apmask=0 if(ncontest.eq.0.or.ncontest.eq.1.or.ncontest.eq.2) then apmask(1:58)=1 llrd(1:58)=apmag*apbits(1:58) else if(ncontest.eq.3) then ! Field Day apmask(1:56)=1 llrd(1:28)=apmag*apbits(1:28) llrd(29:56)=apmag*aphis_fd(1:28) else if(ncontest.eq.4) then ! RTTY RU apmask(2:57)=1 llrd(2:29)=apmag*apmy_ru(1:28) llrd(30:57)=apmag*apbits(30:57) endif endif if(iaptype.eq.4 .or. iaptype.eq.5 .or. iaptype.eq.6) then apmask=0 if(ncontest.le.4) then apmask(1:91)=1 ! mycall, hiscall, RRR|73|RR73 if(iaptype.eq.6) llrd(1:91)=apmag*apbits(1:91) endif endif llr=llrd endif max_iterations=40 message77=0 call clockit('bpdecode',0) call bpdecode174_91(llr,apmask,max_iterations,message77, & cw,nharderror,niterations) call clockit('bpdecode',1) if(sum(message77).eq.0) cycle if( nharderror.ge.0 ) then message77=mod(message77+rvec,2) ! remove rvec scrambling write(c77,'(77i1)') message77(1:77) call unpack77(c77,1,message,unpk77_success) idupe=0 do i=1,ndecodes if(decodes(i).eq.message) idupe=1 enddo if(ibest.le.10 .and. message.eq.msg0) idupe=1 !Already decoded if(idupe.eq.1) exit ndecodes=ndecodes+1 decodes(ndecodes)=message if(snr.gt.0.0) then xsnr=10*log10(snr)-14.0 else xsnr=-20.0 endif nsnr=nint(max(-20.0,xsnr)) freq=f0 tsig=mod(tbuf + ibest/750.0,100.0) write(line,1000) hhmmss,nsnr,tsig,nint(freq),message 1000 format(a6,i4,f5.1,i5,' + ',1x,a37) l1=index(data_dir,char(0))-1 if(l1.ge.1) data_dir(l1+1:l1+1)="/" fname=data_dir(1:l1+1)//'all_ft4.txt' open(24,file=trim(fname),status='unknown',position='append') write(24,1002) cdatetime0,nsnr,tsig,nint(freq),message, & nharderror,nsync_qual,ipass,niterations,iaptype,nsync if(hhmmss.eq.' ') write(*,1002) cdatetime0,nsnr, & tsig,nint(freq),message,nharderror,nsync_qual,ipass, & niterations,iaptype 1002 format(a17,i4,f5.1,i5,' Rx ',a37,6i4) close(24) linex(ndecodes)=line if(ibest.ge.ibmax-15) msg0=message !Possible dupe candidate exit endif enddo !Sequence estimation enddo !Candidate list call clockit('ft4_deco',1) call clockit2(data_dir) call clockit('ft4_deco',101) return entry get_ft4msg(idecode,line) line=linex(idecode) return end subroutine ft4_decode