mirror of https://github.com/saitohirga/WSJT-X.git
Implement coupled BP->OSD decoding for FT8/FT4.
This commit is contained in:
Steven Franke
parent
160a8c896c
commit
093c403063
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@ -428,6 +428,7 @@ set (wsjt_FSRCS
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lib/encode_128_90.f90
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lib/ft8/encode174.f90
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lib/ft8/encode174_91.f90
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lib/ft8/encode174_91_nocrc.f90
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lib/entail.f90
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lib/ephem.f90
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lib/extract.f90
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@ -603,12 +604,14 @@ set (wsjt_FSRCS
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lib/fsk4hf/genwsprcpm.f90
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lib/fsk4hf/encode204.f90
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lib/fsk4hf/decode174_74.f90
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lib/ft8/decode174_91.f90
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lib/fsk4hf/decode240_101.f90
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lib/fsk4hf/decode280_101.f90
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lib/fsk4hf/ldpcsim174_91.f90
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lib/fsk4hf/ldpcsim174_74.f90
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lib/fsk4hf/ldpcsim240_101.f90
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lib/fsk4hf/ldpcsim280_101.f90
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lib/fsk4hf/get_crc14.f90
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lib/fsk4hf/get_crc24.f90
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lib/fsk4hf/encode174_74.f90
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lib/fsk4hf/encode240_101.f90
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@ -1,15 +1,19 @@
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subroutine get_crc14(mc,ncrc)
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subroutine get_crc14(mc,len,ncrc)
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!
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! 1. To calculate 14-bit CRC, mc(1:len-14) is the message and mc(len-13:len) are zero.
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! 2. To check a received CRC, mc(1:len is the received message plus CRC.
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! ncrc will be zero if the received message/CRC are consistent
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!
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character c14*14
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integer*1 mc(68),r(15),p(15)
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integer*1 mc(len)
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integer*1 r(15),p(15)
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integer ncrc
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! polynomial for 14-bit CRC 0x6757
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data p/1,1,0,0,1,1,1,0,1,0,1,0,1,1,1/
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! divide by polynomial
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r=mc(1:15)
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do i=0,53
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do i=0,len-15
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r(15)=mc(i+15)
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r=mod(r+r(1)*p,2)
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r=cshift(r,1)
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@ -17,6 +21,5 @@ subroutine get_crc14(mc,ncrc)
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write(c14,'(14b1)') r(1:14)
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read(c14,'(b14.14)') ncrc
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! mc(55:68)=r(1:14)
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end subroutine get_crc14
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@ -10,7 +10,7 @@ character*6 grid
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character*96 tmpchar
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integer*1, allocatable :: codeword(:), decoded(:), message(:)
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integer*1 msgbits(77)
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integer*1 message77(77)
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integer*1 message77(77),message91(91)
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integer*1 apmask(N), cw(N)
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integer nerrtot(0:N),nerrdec(0:N)
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logical unpk77_success
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@ -21,11 +21,12 @@ nerrtot=0
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nerrdec=0
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nargs=iargc()
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if(nargs.ne.4) then
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print*,'Usage: ldpcsim niter ndepth #trials s '
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print*,'eg: ldpcsim 10 2 1000 0.84'
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if(nargs.ne.6) then
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print*,'Usage: ldpcsim niter ndepth #trials s Keff BPOSD'
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print*,'eg: ldpcsim 10 2 1000 0.84 91 1'
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print*,'belief propagation iterations: niter, ordered-statistics depth: ndepth'
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print*,'If s is negative, then value is ignored and sigma is calculated from SNR.'
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print*,'If BPOSD=0, no coupling. BPOSD=1, BP output to OSD input.'
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return
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endif
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call getarg(1,arg)
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@ -36,9 +37,13 @@ call getarg(3,arg)
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read(arg,*) ntrials
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call getarg(4,arg)
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read(arg,*) s
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call getarg(5,arg)
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read(arg,*) Keff
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call getarg(6,arg)
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read(arg,*) nbposd
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! scale Eb/No for a (174,91) code
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rate=real(K)/real(N)
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rate=real(Keff)/real(N)
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write(*,*) "rate: ",rate
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write(*,*) "niter= ",max_iterations," s= ",s
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@ -46,8 +51,7 @@ write(*,*) "niter= ",max_iterations," s= ",s
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allocate ( codeword(N), decoded(K), message(K) )
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allocate ( rxdata(N), llr(N) )
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! msg="K1JT K9AN EN50"
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msg="G4WJS K9AN EN50"
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msg="K9ABC K1ABC FN20"
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i3=0
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n3=1
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call pack77(msg,i3,n3,c77) !Pack into 12 6-bit bytes
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@ -55,20 +59,19 @@ allocate ( rxdata(N), llr(N) )
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write(*,*) "message sent ",msgsent
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read(c77,'(77i1)') msgbits(1:77)
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write(*,*) 'message'
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write(*,'(a71,1x,a3,1x,a3)') c77(1:71),c77(72:74),c77(75:77)
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call encode174_91(msgbits,codeword)
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call init_random_seed()
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call encode174_91(msgbits,codeword)
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write(*,*) 'crc14'
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write(*,'(14i1)') codeword(78:91)
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write(*,*) 'codeword'
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write(*,'(22(8i1,1x))') codeword
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write(*,*) "Eb/N0 SNR2500 ngood nundetected sigma psymerr"
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do idb = 20,-10,-1
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!do idb = 0,0,-1
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write(*,*) "Eb/N0 SNR2500 ngood nundetected sigma psymerr"
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do idb = 10,-4,-1
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db=idb/2.0-1.0
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sigma=1/sqrt( 2*rate*(10**(db/10.0)) )
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ngood=0
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@ -101,21 +104,26 @@ do idb = 20,-10,-1
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llr(1:nap)=5*(2.0*msgbits(1:nap)-1.0)
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apmask=0
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apmask(1:nap)=1
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! max_iterations is max number of belief propagation iterations
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call bpdecode174_91(llr, apmask, max_iterations, message77, cw, nharderrors,niterations,ncheck)
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if( ndepth .ge. 0 .and. nharderrors .lt. 0 ) call osd174_91(llr, apmask, ndepth, message77, cw, nharderrors, dmin)
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!call decode174_91(llr, apmask, max_iterations, message77, cw, nharderrors,niterations,ncheck,dmin,nsuper)
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call bpdecode174_91(llr, apmask, max_iterations, message77, cw, nhardbp,niterations,ncheck)
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if( ndepth .ge. 0 .and. nhardbp .lt. 0 ) then
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dmin=0.0
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if(nbposd.eq.0) then
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call osd174_91(llr,Keff,apmask,ndepth,message91,cw,nhardosd,dmin)
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else
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maxsuper=2
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call decode174_91(llr,Keff,ndepth,apmask,maxsuper,message91,cw,nhardosd,niterations,ncheck,dmin)
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endif
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! If the decoder finds a valid codeword, nharderrors will be .ge. 0.
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if( nharderrors .ge. 0 ) then
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call extractmessage77(message77,msgreceived)
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nhw=count(cw.ne.codeword)
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if(nhw.eq.0) then ! this is a good decode
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ngood=ngood+1
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nerrdec(nerr)=nerrdec(nerr)+1
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else
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nue=nue+1
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endif
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endif
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if( nhardbp .ge. 0 .or. nhardosd.ge.0 ) then
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nhw=count(cw.ne.codeword)
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if(nhw.eq.0) then ! this is a good decode
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ngood=ngood+1
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nerrdec(nerr)=nerrdec(nerr)+1
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else
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nue=nue+1
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endif
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endif
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nsumerr=nsumerr+nerr
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enddo
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@ -56,6 +56,7 @@ contains
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integer apmy_ru(28),aphis_fd(28)
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integer*2 iwave(NMAX) !Raw received data
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integer*1 message77(77),rvec(77),apmask(2*ND),cw(2*ND)
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integer*1 message91(91)
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integer*1 hbits(2*NN)
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integer i4tone(103)
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integer nappasses(0:5) ! # of decoding passes for QSO States 0-5
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@ -412,12 +413,19 @@ contains
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call timer('bpdec174',1)
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if(doosd .and. nharderror.lt.0) then
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ndeep=3
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! ndeep=3
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ndeep=2
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if(abs(nfqso-f1).le.napwid) then
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ndeep=4
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! ndeep=4
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ndeep=3
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endif
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call timer('osd174_91 ',0)
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call osd174_91(llr,apmask,ndeep,message77,cw,nharderror,dmin)
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Keff=91
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maxsuper=2
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! call osd174_91(llr,Keff,apmask,ndeep,message91,cw,nharderror,dmin)
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call decode174_91(llr,Keff,ndeep,apmask,maxsuper,message91,cw,nharderror, &
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niterations,ncheck,dmin)
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message77=message91(1:77)
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call timer('osd174_91 ',1)
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endif
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@ -1,13 +1,12 @@
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subroutine decode174_91(llr,apmask,maxiterations,message77,cw,nharderror,iter,ncheck,dmin,isuper)
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subroutine decode174_91(llr,Keff,ndeep,apmask,maxsuper,message91,cw,nharderror,iter,ncheck,dmin)
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!
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! A hybrid bp/osd decoder for the (174,91) code.
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!
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use iso_c_binding, only: c_loc,c_size_t
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use crc
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integer, parameter:: N=174, K=91, M=N-K
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integer*1 cw(N),apmask(N)
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integer*1 decoded(K)
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integer*1 message77(77)
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integer*1 nxor(N),hdec(N)
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integer*1 message91(91)
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integer nrw(M),ncw
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integer Nm(7,M)
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integer Mn(3,N) ! 3 checks per bit
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@ -35,7 +34,6 @@ enddo
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ncnt=0
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nclast=0
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maxsuper=5
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maxiterations=1
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zsum=0.0
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@ -63,10 +61,12 @@ zsum=zsum+zn
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! write(*,*) 'number of unsatisfied parity checks ',ncheck
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if( ncheck .eq. 0 ) then ! we have a codeword - if crc is good, return it
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decoded=cw(1:K)
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call chkcrc14a(decoded,nbadcrc)
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call get_crc14(decoded,91,nbadcrc)
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write(*,*) nbadcrc
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write(*,'(91i1)') decoded
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nharderror=count( (2*cw-1)*llr .lt. 0.0 )
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if(nbadcrc.eq.0) then
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message77=decoded(1:77)
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message91=decoded(1:91)
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dmin=0.0
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return
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endif
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@ -118,13 +118,18 @@ dmin=0.0
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enddo
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enddo ! bp iterations
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ndeep=1
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llr=zsum
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call osd174_91(llr,apmask,ndeep,message77,cw,nharderror,dmin)
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call osd174_91(zsum,Keff,apmask,ndeep,message91,cw,nharderror,dminosd)
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if(nharderror.gt.0) then
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hdec=0
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where(llr .ge. 0) hdec=1
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nxor=ieor(hdec,cw)
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dmin=sum(nxor*abs(llr))
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return
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endif
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enddo ! super iterations
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nharderror=-1
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return
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end subroutine decode174_91
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@ -0,0 +1,49 @@
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subroutine encode174_91_nocrc(message,codeword)
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!
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! Add a 14-bit CRC to a 77-bit message and return a 174-bit codeword
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!
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use, intrinsic :: iso_c_binding
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use iso_c_binding, only: c_loc,c_size_t
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use crc
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integer, parameter:: N=174, K=91, M=N-K
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character*91 tmpchar
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integer*1 codeword(N)
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integer*1 gen(M,K)
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integer*1 message(K)
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integer*1 pchecks(M)
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integer*1, target :: i1MsgBytes(12)
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include "ldpc_174_91_c_generator.f90"
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logical first
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data first/.true./
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save first,gen
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if( first ) then ! fill the generator matrix
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gen=0
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do i=1,M
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do j=1,23
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read(g(i)(j:j),"(Z1)") istr
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ibmax=4
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if(j.eq.23) ibmax=3
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do jj=1, ibmax
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icol=(j-1)*4+jj
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if( btest(istr,4-jj) ) gen(i,icol)=1
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enddo
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enddo
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enddo
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first=.false.
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endif
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do i=1,M
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nsum=0
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do j=1,K
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nsum=nsum+message(j)*gen(i,j)
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enddo
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pchecks(i)=mod(nsum,2)
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enddo
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codeword(1:K)=message
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codeword(K+1:N)=pchecks
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return
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end subroutine encode174_91_nocrc
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@ -18,7 +18,7 @@ subroutine ft8b(dd0,newdat,nQSOProgress,nfqso,nftx,ndepth,nzhsym,lapon, &
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real llra(174),llrb(174),llrc(174),llrd(174),llrz(174) !Soft symbols
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real dd0(15*12000)
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real ss(9)
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integer*1 message77(77),apmask(174),cw(174)
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integer*1 message77(77),message91(91),apmask(174),cw(174)
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integer apsym(58),aph10(10)
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integer mcq(29),mcqru(29),mcqfd(29),mcqtest(29),mcqww(29)
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integer mrrr(19),m73(19),mrr73(19)
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@ -407,12 +407,19 @@ subroutine ft8b(dd0,newdat,nQSOProgress,nfqso,nftx,ndepth,nzhsym,lapon, &
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dmin=0.0
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if(nharderrors.lt.0 .and. ncheck.le.30 .and. ndepth.ge.2) then
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ndeep=ndepth
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!ndeep=ndepth-1
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if(abs(nfqso-f1).le.napwid .or. abs(nftx-f1).le.napwid .or. ncontest.eq.7) then
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ndeep=4
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!ndeep=3
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endif
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if(nagain) ndeep=5
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!if(nagain) ndeep=4
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call timer('osd174_91 ',0)
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call osd174_91(llrz,apmask,ndeep,message77,cw,nharderrors,dmin)
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Keff=91
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! call osd174_91(llrz,Keff,apmask,ndeep,message91,cw,nharderrors,dmin)
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maxsuper=2
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call decode174_91(llrz,Keff,ndeep,apmask,maxsuper,message91,cw,nharderrors,niterations,ncheck,dmin)
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if(nharderrors.ge.0) message77=message91(1:77)
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call timer('osd174_91 ',1)
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endif
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@ -1,237 +1,269 @@
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subroutine osd174_91(llr,apmask,ndeep,message77,cw,nhardmin,dmin)
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subroutine osd174_91(llr,k,apmask,ndeep,message91,cw,nhardmin,dmin)
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!
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! An ordered-statistics decoder for the (174,91) code.
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! Message payload is 77 bits. Any or all of a 14-bit CRC can be
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! used for detecting incorrect codewords. The remaining CRC bits are
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! cascaded with the LDPC code for the purpose of improving the
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! distance spectrum of the code.
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!
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! If p1 (0.le.p1.le.14) is the number of CRC14 bits that are
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! to be used for bad codeword detection, then the argument k should
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! be set to 77+p1.
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!
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! Valid values for k are in the range [77,91].
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!
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character*14 c14
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integer, parameter:: N=174
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integer*1 apmask(N),apmaskr(N)
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integer*1, allocatable, save :: gen(:,:)
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integer*1, allocatable :: genmrb(:,:),g2(:,:)
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integer*1, allocatable :: temp(:),m0(:),me(:),mi(:),misub(:),e2sub(:),e2(:),ui(:)
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integer*1, allocatable :: r2pat(:)
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integer indices(N),nxor(N)
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integer*1 cw(N),ce(N),c0(N),hdec(N)
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integer*1, allocatable :: decoded(:)
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integer*1 message91(91),m96(96)
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integer indx(N)
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real llr(N),rx(N),absrx(N)
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logical first,reset
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data first/.true./
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save first
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allocate( genmrb(k,N), g2(N,k) )
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allocate( temp(k), m0(k), me(k), mi(k), misub(k), e2sub(N-k), e2(N-k), ui(N-k) )
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allocate( r2pat(N-k), decoded(k) )
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if( first ) then ! fill the generator matrix
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!
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! Create generator matrix for partial CRC cascaded with LDPC code.
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!
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integer, parameter:: N=174, K=91, M=N-K
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integer*1 apmask(N),apmaskr(N)
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integer*1 gen(K,N)
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integer*1 genmrb(K,N),g2(N,K)
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integer*1 temp(K),m0(K),me(K),mi(K),misub(K),e2sub(N-K),e2(N-K),ui(N-K)
|
||||
integer*1 r2pat(N-K)
|
||||
integer indices(N),nxor(N)
|
||||
integer*1 cw(N),ce(N),c0(N),hdec(N)
|
||||
integer*1 decoded(K)
|
||||
integer*1 message77(77)
|
||||
integer indx(N)
|
||||
real llr(N),rx(N),absrx(N)
|
||||
|
||||
include "ldpc_174_91_c_generator.f90"
|
||||
|
||||
logical first,reset
|
||||
data first/.true./
|
||||
save first,gen
|
||||
|
||||
if( first ) then ! fill the generator matrix
|
||||
gen=0
|
||||
do i=1,M
|
||||
do j=1,23
|
||||
read(g(i)(j:j),"(Z1)") istr
|
||||
ibmax=4
|
||||
if(j.eq.23) ibmax=3
|
||||
do jj=1, ibmax
|
||||
irow=(j-1)*4+jj
|
||||
if( btest(istr,4-jj) ) gen(irow,K+i)=1
|
||||
! Let p2=91-k and p1+p2=14.
|
||||
!
|
||||
! The last p2 bits of the CRC14 are cascaded with the LDPC code.
|
||||
!
|
||||
! The first p1=k-77 CRC14 bits will be used for error detection.
|
||||
!
|
||||
allocate( gen(k,N) )
|
||||
gen=0
|
||||
do i=1,k
|
||||
message91=0
|
||||
message91(i)=1
|
||||
if(i.le.77) then
|
||||
m96=0
|
||||
m96(1:91)=message91
|
||||
call get_crc14(m96,96,ncrc14)
|
||||
write(c14,'(b14.14)') ncrc14
|
||||
read(c14,'(14i1)') message91(78:91)
|
||||
message91(78:k)=0
|
||||
endif
|
||||
call encode174_91_nocrc(message91,cw)
|
||||
gen(i,:)=cw
|
||||
enddo
|
||||
enddo
|
||||
enddo
|
||||
do irow=1,K
|
||||
gen(irow,irow)=1
|
||||
enddo
|
||||
first=.false.
|
||||
endif
|
||||
|
||||
rx=llr
|
||||
apmaskr=apmask
|
||||
first=.false.
|
||||
endif
|
||||
|
||||
rx=llr
|
||||
apmaskr=apmask
|
||||
|
||||
! Hard decisions on the received word.
|
||||
hdec=0
|
||||
where(rx .ge. 0) hdec=1
|
||||
hdec=0
|
||||
where(rx .ge. 0) hdec=1
|
||||
|
||||
! Use magnitude of received symbols as a measure of reliability.
|
||||
absrx=abs(rx)
|
||||
call indexx(absrx,N,indx)
|
||||
absrx=abs(rx)
|
||||
call indexx(absrx,N,indx)
|
||||
|
||||
! Re-order the columns of the generator matrix in order of decreasing reliability.
|
||||
do i=1,N
|
||||
genmrb(1:K,i)=gen(1:K,indx(N+1-i))
|
||||
indices(i)=indx(N+1-i)
|
||||
enddo
|
||||
do i=1,N
|
||||
genmrb(1:k,i)=gen(1:k,indx(N+1-i))
|
||||
indices(i)=indx(N+1-i)
|
||||
enddo
|
||||
|
||||
! Do gaussian elimination to create a generator matrix with the most reliable
|
||||
! received bits in positions 1:K in order of decreasing reliability (more or less).
|
||||
do id=1,K ! diagonal element indices
|
||||
do icol=id,K+20 ! The 20 is ad hoc - beware
|
||||
iflag=0
|
||||
if( genmrb(id,icol) .eq. 1 ) then
|
||||
iflag=1
|
||||
if( icol .ne. id ) then ! reorder column
|
||||
temp(1:K)=genmrb(1:K,id)
|
||||
genmrb(1:K,id)=genmrb(1:K,icol)
|
||||
genmrb(1:K,icol)=temp(1:K)
|
||||
itmp=indices(id)
|
||||
indices(id)=indices(icol)
|
||||
indices(icol)=itmp
|
||||
endif
|
||||
do ii=1,K
|
||||
if( ii .ne. id .and. genmrb(ii,id) .eq. 1 ) then
|
||||
genmrb(ii,1:N)=ieor(genmrb(ii,1:N),genmrb(id,1:N))
|
||||
endif
|
||||
! received bits in positions 1:k in order of decreasing reliability (more or less).
|
||||
do id=1,k ! diagonal element indices
|
||||
do icol=id,k+20 ! The 20 is ad hoc - beware
|
||||
iflag=0
|
||||
if( genmrb(id,icol) .eq. 1 ) then
|
||||
iflag=1
|
||||
if( icol .ne. id ) then ! reorder column
|
||||
temp(1:k)=genmrb(1:k,id)
|
||||
genmrb(1:k,id)=genmrb(1:k,icol)
|
||||
genmrb(1:k,icol)=temp(1:k)
|
||||
itmp=indices(id)
|
||||
indices(id)=indices(icol)
|
||||
indices(icol)=itmp
|
||||
endif
|
||||
do ii=1,k
|
||||
if( ii .ne. id .and. genmrb(ii,id) .eq. 1 ) then
|
||||
genmrb(ii,1:N)=ieor(genmrb(ii,1:N),genmrb(id,1:N))
|
||||
endif
|
||||
enddo
|
||||
exit
|
||||
endif
|
||||
enddo
|
||||
exit
|
||||
endif
|
||||
enddo
|
||||
enddo
|
||||
enddo
|
||||
|
||||
g2=transpose(genmrb)
|
||||
g2=transpose(genmrb)
|
||||
|
||||
! The hard decisions for the K MRB bits define the order 0 message, m0.
|
||||
! Encode m0 using the modified generator matrix to find the "order 0" codeword.
|
||||
! The hard decisions for the k MRB bits define the order 0 message, m0.
|
||||
! Encode m0 using the modified generator matrix to find the "order 0" codeword.
|
||||
! Flip various combinations of bits in m0 and re-encode to generate a list of
|
||||
! codewords. Return the member of the list that has the smallest Euclidean
|
||||
! distance to the received word.
|
||||
! distance to the received word.
|
||||
|
||||
hdec=hdec(indices) ! hard decisions from received symbols
|
||||
m0=hdec(1:K) ! zero'th order message
|
||||
absrx=absrx(indices)
|
||||
rx=rx(indices)
|
||||
apmaskr=apmaskr(indices)
|
||||
hdec=hdec(indices) ! hard decisions from received symbols
|
||||
m0=hdec(1:k) ! zero'th order message
|
||||
absrx=absrx(indices)
|
||||
rx=rx(indices)
|
||||
apmaskr=apmaskr(indices)
|
||||
|
||||
call mrbencode91(m0,c0,g2,N,K)
|
||||
nxor=ieor(c0,hdec)
|
||||
nhardmin=sum(nxor)
|
||||
dmin=sum(nxor*absrx)
|
||||
call mrbencode91(m0,c0,g2,N,k)
|
||||
nxor=ieor(c0,hdec)
|
||||
nhardmin=sum(nxor)
|
||||
dmin=sum(nxor*absrx)
|
||||
|
||||
cw=c0
|
||||
ntotal=0
|
||||
nrejected=0
|
||||
npre1=0
|
||||
npre2=0
|
||||
|
||||
if(ndeep.eq.0) goto 998 ! norder=0
|
||||
if(ndeep.gt.5) ndeep=5
|
||||
if( ndeep.eq. 1) then
|
||||
nord=1
|
||||
cw=c0
|
||||
ntotal=0
|
||||
nrejected=0
|
||||
npre1=0
|
||||
npre2=0
|
||||
nt=40
|
||||
ntheta=12
|
||||
elseif(ndeep.eq.2) then
|
||||
nord=1
|
||||
npre1=1
|
||||
npre2=0
|
||||
nt=40
|
||||
ntheta=12
|
||||
elseif(ndeep.eq.3) then
|
||||
nord=1
|
||||
npre1=1
|
||||
npre2=1
|
||||
nt=40
|
||||
ntheta=12
|
||||
ntau=14
|
||||
elseif(ndeep.eq.4) then
|
||||
nord=2
|
||||
npre1=1
|
||||
npre2=0
|
||||
nt=40
|
||||
ntheta=12
|
||||
ntau=19
|
||||
elseif(ndeep.eq.5) then
|
||||
nord=2
|
||||
npre1=1
|
||||
npre2=1
|
||||
nt=40
|
||||
ntheta=12
|
||||
ntau=19
|
||||
endif
|
||||
|
||||
do iorder=1,nord
|
||||
misub(1:K-iorder)=0
|
||||
misub(K-iorder+1:K)=1
|
||||
iflag=K-iorder+1
|
||||
do while(iflag .ge.0)
|
||||
if(iorder.eq.nord .and. npre1.eq.0) then
|
||||
iend=iflag
|
||||
else
|
||||
iend=1
|
||||
endif
|
||||
d1=0.
|
||||
do n1=iflag,iend,-1
|
||||
mi=misub
|
||||
mi(n1)=1
|
||||
if(any(iand(apmaskr(1:K),mi).eq.1)) cycle
|
||||
ntotal=ntotal+1
|
||||
me=ieor(m0,mi)
|
||||
if(n1.eq.iflag) then
|
||||
call mrbencode91(me,ce,g2,N,K)
|
||||
e2sub=ieor(ce(K+1:N),hdec(K+1:N))
|
||||
e2=e2sub
|
||||
nd1Kpt=sum(e2sub(1:nt))+1
|
||||
d1=sum(ieor(me(1:K),hdec(1:K))*absrx(1:K))
|
||||
if(ndeep.eq.0) goto 998 ! norder=0
|
||||
if(ndeep.gt.6) ndeep=6
|
||||
if( ndeep.eq. 1) then
|
||||
nord=1
|
||||
npre1=0
|
||||
npre2=0
|
||||
nt=40
|
||||
ntheta=12
|
||||
elseif(ndeep.eq.2) then
|
||||
nord=1
|
||||
npre1=1
|
||||
npre2=0
|
||||
nt=40
|
||||
! ntheta=12
|
||||
ntheta=10
|
||||
elseif(ndeep.eq.3) then
|
||||
nord=1
|
||||
npre1=1
|
||||
npre2=1
|
||||
nt=40
|
||||
ntheta=12
|
||||
ntau=14
|
||||
elseif(ndeep.eq.4) then
|
||||
nord=2
|
||||
npre1=1
|
||||
npre2=1
|
||||
nt=40
|
||||
ntheta=12
|
||||
ntau=17
|
||||
elseif(ndeep.eq.5) then
|
||||
nord=3
|
||||
npre1=1
|
||||
npre2=1
|
||||
nt=40
|
||||
ntheta=12
|
||||
ntau=15
|
||||
elseif(ndeep.eq.6) then
|
||||
nord=4
|
||||
npre1=1
|
||||
npre2=1
|
||||
nt=95
|
||||
ntheta=12
|
||||
ntau=15
|
||||
endif
|
||||
|
||||
do iorder=1,nord
|
||||
misub(1:k-iorder)=0
|
||||
misub(k-iorder+1:k)=1
|
||||
iflag=k-iorder+1
|
||||
do while(iflag .ge.0)
|
||||
if(iorder.eq.nord .and. npre1.eq.0) then
|
||||
iend=iflag
|
||||
else
|
||||
e2=ieor(e2sub,g2(K+1:N,n1))
|
||||
nd1Kpt=sum(e2(1:nt))+2
|
||||
iend=1
|
||||
endif
|
||||
if(nd1Kpt .le. ntheta) then
|
||||
call mrbencode91(me,ce,g2,N,K)
|
||||
nxor=ieor(ce,hdec)
|
||||
d1=0.
|
||||
do n1=iflag,iend,-1
|
||||
mi=misub
|
||||
mi(n1)=1
|
||||
if(any(iand(apmaskr(1:k),mi).eq.1)) cycle
|
||||
ntotal=ntotal+1
|
||||
me=ieor(m0,mi)
|
||||
if(n1.eq.iflag) then
|
||||
dd=d1+sum(e2sub*absrx(K+1:N))
|
||||
call mrbencode91(me,ce,g2,N,k)
|
||||
e2sub=ieor(ce(k+1:N),hdec(k+1:N))
|
||||
e2=e2sub
|
||||
nd1kpt=sum(e2sub(1:nt))+1
|
||||
d1=sum(ieor(me(1:k),hdec(1:k))*absrx(1:k))
|
||||
else
|
||||
dd=d1+ieor(ce(n1),hdec(n1))*absrx(n1)+sum(e2*absrx(K+1:N))
|
||||
e2=ieor(e2sub,g2(k+1:N,n1))
|
||||
nd1kpt=sum(e2(1:nt))+2
|
||||
endif
|
||||
if( dd .lt. dmin ) then
|
||||
dmin=dd
|
||||
cw=ce
|
||||
nhardmin=sum(nxor)
|
||||
nd1Kptbest=nd1Kpt
|
||||
if(nd1kpt .le. ntheta) then
|
||||
call mrbencode91(me,ce,g2,N,k)
|
||||
nxor=ieor(ce,hdec)
|
||||
if(n1.eq.iflag) then
|
||||
dd=d1+sum(e2sub*absrx(k+1:N))
|
||||
else
|
||||
dd=d1+ieor(ce(n1),hdec(n1))*absrx(n1)+sum(e2*absrx(k+1:N))
|
||||
endif
|
||||
if( dd .lt. dmin ) then
|
||||
dmin=dd
|
||||
cw=ce
|
||||
nhardmin=sum(nxor)
|
||||
nd1kptbest=nd1kpt
|
||||
endif
|
||||
else
|
||||
nrejected=nrejected+1
|
||||
endif
|
||||
else
|
||||
nrejected=nrejected+1
|
||||
endif
|
||||
enddo
|
||||
enddo
|
||||
! Get the next test error pattern, iflag will go negative
|
||||
! when the last pattern with weight iorder has been generated.
|
||||
call nextpat91(misub,k,iorder,iflag)
|
||||
enddo
|
||||
enddo
|
||||
|
||||
if(npre2.eq.1) then
|
||||
reset=.true.
|
||||
ntotal=0
|
||||
do i1=K,1,-1
|
||||
do i2=i1-1,1,-1
|
||||
ntotal=ntotal+1
|
||||
mi(1:ntau)=ieor(g2(K+1:K+ntau,i1),g2(K+1:K+ntau,i2))
|
||||
call boxit91(reset,mi(1:ntau),ntau,ntotal,i1,i2)
|
||||
call nextpat91(misub,k,iorder,iflag)
|
||||
enddo
|
||||
enddo
|
||||
|
||||
ncount2=0
|
||||
ntotal2=0
|
||||
reset=.true.
|
||||
if(npre2.eq.1) then
|
||||
reset=.true.
|
||||
ntotal=0
|
||||
do i1=k,1,-1
|
||||
do i2=i1-1,1,-1
|
||||
ntotal=ntotal+1
|
||||
mi(1:ntau)=ieor(g2(k+1:k+ntau,i1),g2(k+1:k+ntau,i2))
|
||||
call boxit91(reset,mi(1:ntau),ntau,ntotal,i1,i2)
|
||||
enddo
|
||||
enddo
|
||||
|
||||
ncount2=0
|
||||
ntotal2=0
|
||||
reset=.true.
|
||||
! Now run through again and do the second pre-processing rule
|
||||
misub(1:K-nord)=0
|
||||
misub(K-nord+1:K)=1
|
||||
iflag=K-nord+1
|
||||
do while(iflag .ge.0)
|
||||
me=ieor(m0,misub)
|
||||
call mrbencode91(me,ce,g2,N,K)
|
||||
e2sub=ieor(ce(K+1:N),hdec(K+1:N))
|
||||
do i2=0,ntau
|
||||
ntotal2=ntotal2+1
|
||||
ui=0
|
||||
if(i2.gt.0) ui(i2)=1
|
||||
r2pat=ieor(e2sub,ui)
|
||||
778 continue
|
||||
misub(1:k-nord)=0
|
||||
misub(k-nord+1:k)=1
|
||||
iflag=k-nord+1
|
||||
do while(iflag .ge.0)
|
||||
me=ieor(m0,misub)
|
||||
call mrbencode91(me,ce,g2,N,k)
|
||||
e2sub=ieor(ce(k+1:N),hdec(k+1:N))
|
||||
do i2=0,ntau
|
||||
ntotal2=ntotal2+1
|
||||
ui=0
|
||||
if(i2.gt.0) ui(i2)=1
|
||||
r2pat=ieor(e2sub,ui)
|
||||
778 continue
|
||||
call fetchit91(reset,r2pat(1:ntau),ntau,in1,in2)
|
||||
if(in1.gt.0.and.in2.gt.0) then
|
||||
ncount2=ncount2+1
|
||||
mi=misub
|
||||
mi=misub
|
||||
mi(in1)=1
|
||||
mi(in2)=1
|
||||
if(sum(mi).lt.nord+npre1+npre2.or.any(iand(apmaskr(1:K),mi).eq.1)) cycle
|
||||
if(sum(mi).lt.nord+npre1+npre2.or.any(iand(apmaskr(1:k),mi).eq.1)) cycle
|
||||
me=ieor(m0,mi)
|
||||
call mrbencode91(me,ce,g2,N,K)
|
||||
call mrbencode91(me,ce,g2,N,k)
|
||||
nxor=ieor(ce,hdec)
|
||||
dd=sum(nxor*absrx)
|
||||
if( dd .lt. dmin ) then
|
||||
|
|
@ -240,136 +272,138 @@ if(npre2.eq.1) then
|
|||
nhardmin=sum(nxor)
|
||||
endif
|
||||
goto 778
|
||||
endif
|
||||
endif
|
||||
enddo
|
||||
call nextpat91(misub,k,nord,iflag)
|
||||
enddo
|
||||
call nextpat91(misub,K,nord,iflag)
|
||||
enddo
|
||||
endif
|
||||
endif
|
||||
|
||||
998 continue
|
||||
! Re-order the codeword to [message bits][parity bits] format.
|
||||
cw(indices)=cw
|
||||
hdec(indices)=hdec
|
||||
decoded=cw(1:K)
|
||||
call chkcrc14a(decoded,nbadcrc)
|
||||
message77=decoded(1:77)
|
||||
if(nbadcrc.eq.1) nhardmin=-nhardmin
|
||||
! Re-order the codeword to [message bits][parity bits] format.
|
||||
cw(indices)=cw
|
||||
hdec(indices)=hdec
|
||||
message91=cw(1:91)
|
||||
m96=0
|
||||
m96(1:77)=cw(1:77)
|
||||
m96(83:96)=cw(78:91)
|
||||
call get_crc14(m96,96,nbadcrc)
|
||||
if(nbadcrc.ne.0) nhardmin=-nhardmin
|
||||
|
||||
return
|
||||
return
|
||||
end subroutine osd174_91
|
||||
|
||||
subroutine mrbencode91(me,codeword,g2,N,K)
|
||||
integer*1 me(K),codeword(N),g2(N,K)
|
||||
integer*1 me(K),codeword(N),g2(N,K)
|
||||
! fast encoding for low-weight test patterns
|
||||
codeword=0
|
||||
do i=1,K
|
||||
if( me(i) .eq. 1 ) then
|
||||
codeword=ieor(codeword,g2(1:N,i))
|
||||
endif
|
||||
enddo
|
||||
return
|
||||
codeword=0
|
||||
do i=1,K
|
||||
if( me(i) .eq. 1 ) then
|
||||
codeword=ieor(codeword,g2(1:N,i))
|
||||
endif
|
||||
enddo
|
||||
return
|
||||
end subroutine mrbencode91
|
||||
|
||||
subroutine nextpat91(mi,k,iorder,iflag)
|
||||
integer*1 mi(k),ms(k)
|
||||
integer*1 mi(k),ms(k)
|
||||
! generate the next test error pattern
|
||||
ind=-1
|
||||
do i=1,k-1
|
||||
if( mi(i).eq.0 .and. mi(i+1).eq.1) ind=i
|
||||
enddo
|
||||
if( ind .lt. 0 ) then ! no more patterns of this order
|
||||
iflag=ind
|
||||
return
|
||||
endif
|
||||
ms=0
|
||||
ms(1:ind-1)=mi(1:ind-1)
|
||||
ms(ind)=1
|
||||
ms(ind+1)=0
|
||||
if( ind+1 .lt. k ) then
|
||||
nz=iorder-sum(ms)
|
||||
ms(k-nz+1:k)=1
|
||||
endif
|
||||
mi=ms
|
||||
do i=1,k ! iflag will point to the lowest-index 1 in mi
|
||||
if(mi(i).eq.1) then
|
||||
iflag=i
|
||||
exit
|
||||
endif
|
||||
enddo
|
||||
return
|
||||
ind=-1
|
||||
do i=1,k-1
|
||||
if( mi(i).eq.0 .and. mi(i+1).eq.1) ind=i
|
||||
enddo
|
||||
if( ind .lt. 0 ) then ! no more patterns of this order
|
||||
iflag=ind
|
||||
return
|
||||
endif
|
||||
ms=0
|
||||
ms(1:ind-1)=mi(1:ind-1)
|
||||
ms(ind)=1
|
||||
ms(ind+1)=0
|
||||
if( ind+1 .lt. k ) then
|
||||
nz=iorder-sum(ms)
|
||||
ms(k-nz+1:k)=1
|
||||
endif
|
||||
mi=ms
|
||||
do i=1,k ! iflag will point to the lowest-index 1 in mi
|
||||
if(mi(i).eq.1) then
|
||||
iflag=i
|
||||
exit
|
||||
endif
|
||||
enddo
|
||||
return
|
||||
end subroutine nextpat91
|
||||
|
||||
subroutine boxit91(reset,e2,ntau,npindex,i1,i2)
|
||||
integer*1 e2(1:ntau)
|
||||
integer indexes(5000,2),fp(0:525000),np(5000)
|
||||
logical reset
|
||||
common/boxes/indexes,fp,np
|
||||
integer*1 e2(1:ntau)
|
||||
integer indexes(5000,2),fp(0:525000),np(5000)
|
||||
logical reset
|
||||
common/boxes/indexes,fp,np
|
||||
|
||||
if(reset) then
|
||||
patterns=-1
|
||||
fp=-1
|
||||
np=-1
|
||||
sc=-1
|
||||
indexes=-1
|
||||
reset=.false.
|
||||
endif
|
||||
|
||||
indexes(npindex,1)=i1
|
||||
indexes(npindex,2)=i2
|
||||
ipat=0
|
||||
do i=1,ntau
|
||||
if(e2(i).eq.1) then
|
||||
ipat=ipat+ishft(1,ntau-i)
|
||||
endif
|
||||
enddo
|
||||
if(reset) then
|
||||
patterns=-1
|
||||
fp=-1
|
||||
np=-1
|
||||
sc=-1
|
||||
indexes=-1
|
||||
reset=.false.
|
||||
endif
|
||||
|
||||
ip=fp(ipat) ! see what's currently stored in fp(ipat)
|
||||
if(ip.eq.-1) then
|
||||
fp(ipat)=npindex
|
||||
else
|
||||
do while (np(ip).ne.-1)
|
||||
ip=np(ip)
|
||||
enddo
|
||||
np(ip)=npindex
|
||||
endif
|
||||
return
|
||||
indexes(npindex,1)=i1
|
||||
indexes(npindex,2)=i2
|
||||
ipat=0
|
||||
do i=1,ntau
|
||||
if(e2(i).eq.1) then
|
||||
ipat=ipat+ishft(1,ntau-i)
|
||||
endif
|
||||
enddo
|
||||
|
||||
ip=fp(ipat) ! see what's currently stored in fp(ipat)
|
||||
if(ip.eq.-1) then
|
||||
fp(ipat)=npindex
|
||||
else
|
||||
do while (np(ip).ne.-1)
|
||||
ip=np(ip)
|
||||
enddo
|
||||
np(ip)=npindex
|
||||
endif
|
||||
return
|
||||
end subroutine boxit91
|
||||
|
||||
subroutine fetchit91(reset,e2,ntau,i1,i2)
|
||||
integer indexes(5000,2),fp(0:525000),np(5000)
|
||||
integer lastpat
|
||||
integer*1 e2(ntau)
|
||||
logical reset
|
||||
common/boxes/indexes,fp,np
|
||||
save lastpat,inext
|
||||
integer indexes(5000,2),fp(0:525000),np(5000)
|
||||
integer lastpat
|
||||
integer*1 e2(ntau)
|
||||
logical reset
|
||||
common/boxes/indexes,fp,np
|
||||
save lastpat,inext
|
||||
|
||||
if(reset) then
|
||||
lastpat=-1
|
||||
reset=.false.
|
||||
endif
|
||||
if(reset) then
|
||||
lastpat=-1
|
||||
reset=.false.
|
||||
endif
|
||||
|
||||
ipat=0
|
||||
do i=1,ntau
|
||||
if(e2(i).eq.1) then
|
||||
ipat=ipat+ishft(1,ntau-i)
|
||||
endif
|
||||
enddo
|
||||
index=fp(ipat)
|
||||
ipat=0
|
||||
do i=1,ntau
|
||||
if(e2(i).eq.1) then
|
||||
ipat=ipat+ishft(1,ntau-i)
|
||||
endif
|
||||
enddo
|
||||
index=fp(ipat)
|
||||
|
||||
if(lastpat.ne.ipat .and. index.gt.0) then ! return first set of indices
|
||||
i1=indexes(index,1)
|
||||
i2=indexes(index,2)
|
||||
inext=np(index)
|
||||
elseif(lastpat.eq.ipat .and. inext.gt.0) then
|
||||
i1=indexes(inext,1)
|
||||
i2=indexes(inext,2)
|
||||
inext=np(inext)
|
||||
else
|
||||
i1=-1
|
||||
i2=-1
|
||||
inext=-1
|
||||
endif
|
||||
lastpat=ipat
|
||||
return
|
||||
if(lastpat.ne.ipat .and. index.gt.0) then ! return first set of indices
|
||||
i1=indexes(index,1)
|
||||
i2=indexes(index,2)
|
||||
inext=np(index)
|
||||
elseif(lastpat.eq.ipat .and. inext.gt.0) then
|
||||
i1=indexes(inext,1)
|
||||
i2=indexes(inext,2)
|
||||
inext=np(inext)
|
||||
else
|
||||
i1=-1
|
||||
i2=-1
|
||||
inext=-1
|
||||
endif
|
||||
lastpat=ipat
|
||||
return
|
||||
end subroutine fetchit91
|
||||
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue