subroutine ft8b(dd0,newdat,nfqso,ndepth,icand,sync0,f1,xdt,apsym,nharderrors, & dmin,nbadcrc,message,xsnr) use timer_module, only: timer include 'ft8_params.f90' parameter(NRECENT=10,NP2=2812) character message*22,msgsent*22 character*12 recent_calls(NRECENT) real a(5) real s1(0:7,ND),s2(0:7,NN) real ps(0:7) real rxdata(3*ND),llr(3*ND),llrap(3*ND) !Soft symbols real dd0(15*12000) integer*1 decoded(KK),apmask(3*ND),cw(3*ND) integer*1 msgbits(KK) integer apsym(KK),rr73(11) integer itone(NN) complex cd0(3200) complex ctwk(32) complex csymb(32) logical newdat data rr73/-1,1,1,1,1,1,1,-1,1,1,-1/ max_iterations=40 norder=2 if(ndepth.eq.3 .and. abs(nfqso-f1).lt.10.0) norder=3 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*fs2) !Initial guess for start of signal smax=0.0 do idt=i0-16,i0+16 !Search over +/- half a 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,2,sync) j=0 do k=1,NN i1=ibest+(k-1)*32 csymb=cmplx(0.0,0.0) if( i1.ge.1 .and. i1+31 .le. NP2 ) csymb=cd0(i1:i1+31) call four2a(csymb,32,1,-1,1) s2(0:7,k)=abs(csymb(1:8)) enddo j=0 do k=1,NN if(k.le.7) cycle if(k.ge.37 .and. k.le.43) cycle if(k.gt.72) cycle j=j+1 s1(0:7,j)=s2(0:7,k) enddo do j=1,ND ps=s1(0:7,j) where (ps.gt.0.0) ps=log(ps) r1=max(ps(1),ps(3),ps(5),ps(7))-max(ps(0),ps(2),ps(4),ps(6)) r2=max(ps(2),ps(3),ps(6),ps(7))-max(ps(0),ps(1),ps(4),ps(5)) r4=max(ps(4),ps(5),ps(6),ps(7))-max(ps(0),ps(1),ps(2),ps(3)) rxdata(3*j-2)=r4 rxdata(3*j-1)=r2 rxdata(3*j)=r1 enddo rxav=sum(rxdata)/(3.0*ND) rx2av=sum(rxdata*rxdata)/(3.0*ND) var=rx2av-rxav*rxav if( var .gt. 0.0 ) then rxsig=sqrt(var) else rxsig=sqrt(rx2av) endif rxdata=rxdata/rxsig ss=0.84 llr=2.0*rxdata/(ss*ss) ! do iap=0,3 do iap=0,0 !### Temporary ### if(iap.eq.0) then apmask=0 apmask(160:162)=1 llrap=llr llrap(160:162)=5.0*apsym(73:75)/ss elseif(iap.eq.1) then apmask=0 apmask(88:115)=1 ! mycall apmask(160:162)=1 ! 3 extra bits llrap=0.0 llrap(88:115)=5.0*apsym(1:28)/ss llrap(160:162)=5.0*apsym(73:75)/ss where(apmask.eq.0) llrap=llr elseif(iap.eq.2) then apmask=0 apmask(88:115)=1 ! mycall apmask(116:143)=1 ! hiscall apmask(160:162)=1 ! 3 extra bits llrap=0.0 llrap(88:143)=5.0*apsym(1:56)/ss llrap(160:162)=5.0*apsym(73:75)/ss where(apmask.eq.0) llrap=llr elseif(iap.eq.3) then apmask=0 apmask(88:115)=1 ! mycall apmask(116:143)=1 ! hiscall apmask(144:154)=1 ! RRR or 73 apmask(160:162)=1 ! 3 extra bits llrap=0.0 llrap(88:143)=5.0*apsym(1:56)/ss llrap(144:154)=5.0*rr73/ss llrap(160:162)=5.0*apsym(73:75)/ss where(apmask.eq.0) llrap=llr endif cw=0 call timer('bpd174 ',0) call bpdecode174(llrap,apmask,max_iterations,decoded,cw,nharderrors) call timer('bpd174 ',1) dmin=0.0 if(nharderrors.lt.0 .and. ndepth.ge.2) then call timer('osd174 ',0) call osd174(llr,norder,decoded,cw,nharderrors,dmin) call timer('osd174 ',1) endif nbadcrc=1 message=' ' xsnr=-99.0 if(count(cw.eq.0).eq.174) cycle !Reject the all-zero codeword if( nharderrors.ge.0 .and. dmin.le.30.0 .and. nharderrors .lt. 30) then call chkcrc12a(decoded,nbadcrc) else nharderrors=-1 cycle endif if(nbadcrc.eq.0) then call extractmessage174(decoded,message,ncrcflag,recent_calls,nrecent) call genft8(message,msgsent,msgbits,itone) ! call subtractft8(dd0,itone,f1,xdt2) xsig=0.0 xnoi=0.0 do i=1,79 xsig=xsig+s2(itone(i),i)**2 ios=mod(itone(i)+4,7) xnoi=xnoi+s2(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 if( xsnr .lt. -24.0 ) xsnr=-24.0 ! write(50,3050) icand,sync0,f1,xdt,nharderrors,dmin,message,iap !3050 format(i3,3f10.3,i5,f10.3,2x,a22,i3) return endif enddo return end subroutine ft8b