mirror of https://github.com/saitohirga/WSJT-X.git
Progress on msk40.
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6973 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
This commit is contained in:
Steven Franke
parent
2cf32da1ea
commit
b449fd071c
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@ -1,7 +1,7 @@
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subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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use timer_module, only: timer
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parameter (NSPM=240, NPTS=3*NSPM, MAXSTEPS=7500, NFFT=3*NSPM, MAXCAND=10)
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parameter (NSPM=240, NPTS=3*NSPM, MAXSTEPS=7500, NFFT=3*NSPM, MAXCAND=5)
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character*4 rpt(0:63)
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character*6 mycall,hiscall
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character*22 hashmsg,msgreceived
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@ -111,7 +111,7 @@ subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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call init_ldpc(trim(pchk_file)//char(0),trim(gen_file)//char(0))
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! Fill the detmet, detferr arrays
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nstepsize=48 ! 4ms steps
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nstepsize=60 ! 5ms steps
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nstep=(n-NPTS)/nstepsize
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detmet=0
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detmax=-999.99
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@ -193,7 +193,8 @@ subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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nmessages=0
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lines=char(0)
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ncalls=0
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do ip=1,ndet !run through the candidates and try to sync/demod/decode
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imid=times(ip)*fs
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if( imid .lt. NPTS/2 ) imid=NPTS/2
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@ -238,7 +239,7 @@ subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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!do i=1,6
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!write(*,*) i,ipeaks(i)
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!enddo
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do ipk=1,6
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do ipk=1,4
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! we want ic to be the index of the first sample of the frame
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ic0=ipeaks(ipk)
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@ -279,16 +280,14 @@ subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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ferr2=atan2(imag(cfac),real(cfac))/(twopi*40*6*dt)
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endif
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! Final estimate of the carrier frequency - returned to the calling program
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fest=1500+ferr+ferr2
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do idf=0,6 ! frequency jitter
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if( idf .eq. 0 ) then
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deltaf=0.0
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elseif( mod(idf,2) .eq. 0 ) then
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deltaf=4*idf
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deltaf=2.5*idf
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else
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deltaf=-4*(idf+1)
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deltaf=-2.5*(idf+1)
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endif
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! Remove fine frequency error
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@ -313,8 +312,8 @@ subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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phase0=atan2(imag(cca),real(cca))
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do ipha=1,3
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if( ipha.eq.2 ) phase0=phase0-20*pi/180.0
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if( ipha.eq.3 ) phase0=phase0+20*pi/180.0
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if( ipha.eq.2 ) phase0=phase0-30*pi/180.0
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if( ipha.eq.3 ) phase0=phase0+30*pi/180.0
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! Remove phase error - want constellation rotated so that sample points lie on I/Q axes
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cfac=cmplx(cos(phase0),sin(phase0))
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@ -350,16 +349,18 @@ subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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ssig=sqrt(s2av-sav*sav)
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softbits=softbits/ssig
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sigma=0.75
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sigma=0.65
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lratio(1:32)=exp(2.0*softbits(9:40)/(sigma*sigma))
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max_iterations=5
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max_dither=1
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niterations=0
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call ldpc_decode(lratio,decoded,max_iterations,niterations,max_dither,ndither)
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ncalls=ncalls+1
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nhashflag=0
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if( niterations .ge. 0 ) then
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imsg=0
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do i=1,16
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imsg=ishft(imsg,1)+iand(1 , decoded(17-i))
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@ -367,10 +368,20 @@ subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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nrxrpt=iand(imsg,63)
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nrxhash=(imsg-nrxrpt)/64
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if( nrxhash .eq. nhashes(nrxrpt) ) then
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fest=1500+ferr+ferr2+deltaf
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!write(14,'(i6.6,10i5,2f7.1)') nutc,ip,ipk,id,idf,iav,ipha,niterations,nbadsync,nrxrpt,ncalls,ferr,ferr2
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nhashflag=1
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goto 999
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msgreceived=' '
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nmessages=1
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write(msgreceived,'(a1,a,1x,a,a1,1x,a4)') "<",trim(mycall), &
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trim(hiscall),">",rpt(nrxrpt)
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write(lines(nmessages),1020) nutc,nsnr,t0,nint(fest),msgreceived
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1020 format(i6.6,i4,f5.1,i5,' & ',a22)
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return
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endif
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endif
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enddo ! phase loop
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enddo ! frame averaging loop
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enddo ! frequency dithering loop
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@ -378,16 +389,4 @@ subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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enddo ! time-sync correlation-peak loop
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enddo ! candidate loop
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return
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999 continue
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msgreceived=' '
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if( nhashflag.eq.1 ) then
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nmessages=1
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write(msgreceived,'(a1,a,1x,a,a1,1x,a4)') "<",trim(mycall), &
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trim(hiscall),">",rpt(nrxrpt)
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write(lines(nmessages),1020) nutc,nsnr,t0,nint(fest),msgreceived
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1020 format(i6.6,i4,f5.1,i5,' & ',a22)
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endif
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return
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end subroutine detectmsk40
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