diff --git a/lib/ft4_decode.f90 b/lib/ft4_decode.f90 new file mode 100644 index 000000000..b3a81c3d4 --- /dev/null +++ b/lib/ft4_decode.f90 @@ -0,0 +1,478 @@ +module ft4_decode + + type :: ft4_decoder + procedure(ft4_decode_callback), pointer :: callback + contains + procedure :: decode + end type ft4_decoder + + abstract interface + subroutine ft4_decode_callback (this,sync,snr,dt,freq,decoded,nap,qual) + import ft4_decoder + implicit none + class(ft4_decoder), intent(inout) :: this + real, intent(in) :: sync + integer, intent(in) :: snr + real, intent(in) :: dt + real, intent(in) :: freq + character(len=37), intent(in) :: decoded + integer, intent(in) :: nap + real, intent(in) :: qual + end subroutine ft4_decode_callback + end interface + +contains + + subroutine decode(this,callback,iwave,nQSOProgress,nfqso, & + nutc,nfa,nfb,ndepth,ncontest,mycall,hiscall) + use timer_module, only: timer + use packjt77 + include 'ft4/ft4_params.f90' + class(ft4_decoder), intent(inout) :: this + procedure(ft4_decode_callback) :: callback + parameter (NSS=NSPS/NDOWN) + + character message*37,msgsent*37,msg0*37 + character c77*77 + 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(2*NSS),ctwk2(2*NSS,-16:16) + 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, dobigfft + + 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,apbits,nappasses,naptypes, & + mycall0,hiscall0,msg0,cqstr0,ctwk2 + + this%callback => callback + + 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 + + do idf=-16,16 + a=0. + a(1)=real(idf) + ctwk=1. + call twkfreq1(ctwk,2*NSS,fs/2.0,a,ctwk2(:,idf)) + 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 getcandidates4(iwave,fa,fb,syncmin,nfqso,maxcand,savg,candidate, & + ncand,sbase) + + ndecodes=0 + dobigfft=.true. + do icand=1,ncand + f0=candidate(1,icand) + snr=candidate(3,icand)-1.0 + call ft4_downsample(iwave,dobigfft,f0,cd2) !Downsample to 32 Sam/Sym + if(dobigfft) dobigfft=.false. + 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 + ibmax=432 + 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 + do istart=ibmin,ibmax,ibstp + call sync4d(cd2,istart,ctwk2(:,idf),1,sync) !Find sync power + if(sync.gt.smax) then + smax=sync + ibest=istart + idfbest=idf + endif + enddo + enddo + enddo + f0=f0+real(idfbest) + if( f0.le.10.0 .or. f0.ge.4990.0 ) cycle +! write(*,3002) smax,ibest/750.0,f0 +!3002 format('b',3f8.2) + call ft4_downsample(iwave,dobigfft,f0,cb) !Final downsample with corrected f0 + sum2=sum(abs(cb)**2)/(real(NSS)*NN) + if(sum2.gt.0.0) cb=cb/sqrt(sum2) + cd=cb(ibest:ibest+NN*NSS-1) + 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 + +! 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 normalizebmet(bmeta,2*NN) + call normalizebmet(bmetb,2*NN) + call normalizebmet(bmetc,2*NN) + + 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 bpdecode174_91(llr,apmask,max_iterations,message77, & + cw,nharderror,niterations) + 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)) + xdt=ibest/750.0 - 0.45 + call this%callback(sync,nsnr,xdt,f0,message,iaptype,qual) + if(ibest.ge.ibmax-15) msg0=message !Possible dupe candidate + exit + endif + enddo !Sequence estimation + enddo !Candidate list + + return + end subroutine decode + +end module ft4_decode