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https://github.com/saitohirga/WSJT-X.git
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Add a new (174,74) LDPC code (regular, column weight 3) and supporting files.
This commit is contained in:
parent
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commit
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113
lib/fsk4hf/bpdecode174_74.f90
Normal file
113
lib/fsk4hf/bpdecode174_74.f90
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@ -0,0 +1,113 @@
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subroutine bpdecode174_74(llr,apmask,maxiterations,message50,cw,nharderror,iter)
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!
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! A log-domain belief propagation decoder for the (174,74) code.
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!
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integer, parameter:: N=174, K=74, 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 message50(50)
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integer nrw(M),ncw
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integer Nm(6,M)
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integer Mn(3,N) ! 3 checks per bit
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integer synd(M)
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real tov(3,N)
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real toc(6,M)
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real tanhtoc(6,M)
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real zn(N)
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real llr(N)
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real Tmn
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include "ldpc_174_74_parity.f90"
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decoded=0
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toc=0
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tov=0
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tanhtoc=0
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! initialize messages to checks
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do j=1,M
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do i=1,nrw(j)
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toc(i,j)=llr((Nm(i,j)))
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enddo
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enddo
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ncnt=0
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nclast=0
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do iter=0,maxiterations
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! Update bit log likelihood ratios (tov=0 in iteration 0).
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do i=1,N
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if( apmask(i) .ne. 1 ) then
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zn(i)=llr(i)+sum(tov(1:ncw,i))
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else
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zn(i)=llr(i)
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endif
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enddo
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! Check to see if we have a codeword (check before we do any iteration).
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cw=0
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where( zn .gt. 0. ) cw=1
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ncheck=0
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do i=1,M
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synd(i)=sum(cw(Nm(1:nrw(i),i)))
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if( mod(synd(i),2) .ne. 0 ) ncheck=ncheck+1
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! if( mod(synd(i),2) .ne. 0 ) write(*,*) 'check ',i,' unsatisfied'
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enddo
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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(1:74)
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call get_crc24(decoded,nbadcrc)
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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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message50=decoded(1:50)
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return
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endif
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endif
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if( iter.gt.0 ) then ! this code block implements an early stopping criterion
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! if( iter.gt.10000 ) then ! this code block implements an early stopping criterion
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nd=ncheck-nclast
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if( nd .lt. 0 ) then ! # of unsatisfied parity checks decreased
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ncnt=0 ! reset counter
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else
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ncnt=ncnt+1
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endif
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! write(*,*) iter,ncheck,nd,ncnt
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if( ncnt .ge. 5 .and. iter .ge. 10 .and. ncheck .gt. 15) then
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nharderror=-1
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return
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endif
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endif
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nclast=ncheck
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! Send messages from bits to check nodes
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do j=1,M
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do i=1,nrw(j)
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ibj=Nm(i,j)
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toc(i,j)=zn(ibj)
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do kk=1,ncw ! subtract off what the bit had received from the check
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if( Mn(kk,ibj) .eq. j ) then
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toc(i,j)=toc(i,j)-tov(kk,ibj)
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endif
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enddo
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enddo
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enddo
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! send messages from check nodes to variable nodes
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do i=1,M
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tanhtoc(1:6,i)=tanh(-toc(1:6,i)/2)
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enddo
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do j=1,N
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do i=1,ncw
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ichk=Mn(i,j) ! Mn(:,j) are the checks that include bit j
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Tmn=product(tanhtoc(1:nrw(ichk),ichk),mask=Nm(1:nrw(ichk),ichk).ne.j)
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call platanh(-Tmn,y)
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! y=atanh(-Tmn)
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tov(i,j)=2*y
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enddo
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enddo
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enddo
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nharderror=-1
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return
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end subroutine bpdecode174_74
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47
lib/fsk4hf/encode174_74.f90
Normal file
47
lib/fsk4hf/encode174_74.f90
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@ -0,0 +1,47 @@
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subroutine encode174_74(message,codeword)
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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=74, M=N-K
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character*24 c24
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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(10)
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integer*4 ncrc24
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include "ldpc_174_74_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=1,19
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read(g(i)(j:j),"(Z1)") istr
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ibmax=4
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if(j.eq.19) ibmax=2
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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_74
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25
lib/fsk4hf/get_crc24.f90
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25
lib/fsk4hf/get_crc24.f90
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@ -0,0 +1,25 @@
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subroutine get_crc24(mc,ncrc)
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!
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! 1. To calculate 24-bit CRC, mc(1:50) is the message and mc(51:74) are zero.
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! 2. To check a received CRC, mc(1:74) 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 c24*24
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integer*1 mc(74),r(25),p(25)
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integer ncrc
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! polynomial for 24-bit CRC 0x100065b
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data p/1,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,0,0,1,0,1,1,0,1,1/
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! divide by polynomial
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r=mc(1:25)
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do i=0,49
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r(25)=mc(i+25)
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r=mod(r+r(1)*p,2)
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r=cshift(r,1)
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enddo
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write(c24,'(24b1)') r(1:24)
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read(c24,'(b24.24)') ncrc
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end subroutine get_crc24
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105
lib/fsk4hf/ldpc_174_74_generator.f90
Normal file
105
lib/fsk4hf/ldpc_174_74_generator.f90
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@ -0,0 +1,105 @@
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! generator matrix for regular column weight 3 (174,74) LDPC code.
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character*19 g(100)
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data g/ &
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"b190e319bd45882ed74", &
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"b159282d395467cabe4", &
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"f502387ec63db738358", &
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"a6c7911729277b2a178", &
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"05d812d04122ff2842c", &
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"eb040701b66b26d12ec", &
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"c617358e34398e73c6c", &
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"37b62b499bbb84aeb0c", &
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"60257b5d4e41594a250", &
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"e8ac26253c0268ba33c", &
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"0f243baf67353230318", &
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"521d5eb1268bed86854", &
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"53bab7dbe89962bba00", &
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"417abaf10e0912604b8", &
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"c0d371dbb301f49aae8", &
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"e7014cf533a2cb9fd24", &
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"948175882e16ecd8cc8", &
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"87db37137999fb15504", &
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"2557139852451e678c8", &
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"aaaf0b6b1f70db8e5ac", &
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"f5be069b0a41fd5bb28", &
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"e7789f2237b2175d494", &
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"94554737d22b00d5980", &
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"525e935db67c1af214c", &
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"9c57c640427a2c2e33c", &
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"9a82e00fb570e371cac", &
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"39ebbdd43570f690818", &
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"a037514614e0d5cc2a4", &
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"ff19fc0eee4376f6de0", &
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"f8853aad262b1a14cf0", &
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"f5687424fe7c5156ee0", &
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"fba0aa4876b79e45d78", &
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"dfdfb60046769dec900", &
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"600b4517a14560fad64", &
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"39c618d3f629809c064", &
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"5c821087e8c365869f8", &
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"a4f26e15e3ef8264c04", &
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"ac230e4147016f5bf98", &
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"e11a6981f5257957d84", &
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"b9dd003c09cf2abc5b0", &
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"326ff2588a1bfa6a310", &
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"a84e8e04722185f23ac", &
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"8a66abe81aff313f9a8", &
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"f6047ea2cad01957e08", &
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"f14b63fdff262eb74bc", &
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"7588be7336de21f7680", &
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"312d0e1d5d1c3666fec", &
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"5ab69333712cdbf9c38", &
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"3c8e8c949be183939f4", &
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"ed3b36d068e55ef76d8", &
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"8193b051800415c06e0", &
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"bc8e88949be18393bd4", &
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"a7db37037999fb15404", &
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"c5ec69ecc57ed7800b8", &
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"475b645148268e10afc", &
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"1fe90fea7ae941c04a8", &
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"513b196d2a6e43c9504", &
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"ffc27ceba420d04f468", &
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"972c2cc31e578dba968", &
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"7fc874b734a8188a2f8", &
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"3d0327a801275734cc4", &
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"b1e77d50857f56b6a40", &
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"f25389644e47dae2384", &
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"4e7e815e6b3c20507a0", &
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"27d63d2e80a23f057cc", &
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"381388a8a6fad77ec50", &
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"b785abf747ea18bc350", &
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"40a2a8214e2bed48090", &
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"0e891f175b06fed80d4", &
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"dbd155acd9fbec5b4a4", &
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"9d3476e615c702f8e60", &
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"050ea06fbd1f532d164", &
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"d03767bca8394f31628", &
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"455d568ff3047e9d5ac", &
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"6b343bcf7378e1283f4", &
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"a0d371dbb311f49aae8", &
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"36ea237c911eb2ac27c", &
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"54a636ec612a744f368", &
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"5cabf5c9d5a0d2d9ba4", &
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"00d632bffc3dac0d548", &
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"d86bf5593c70dcb91fc", &
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"bada10bb78be8c219c0", &
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"b98028f926fed2beab0", &
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"c0347b3cc45c2888094", &
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"0662d6a3c2974e0a910", &
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"8036b9e83c9fdc2cda8", &
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"e5db38aad196024c21c", &
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"746c8af5783b5daedcc", &
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"1dc47211c27e39ec5dc", &
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"6b98898e40559a2e128", &
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"52d9077dbfa44c6d75c", &
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"9ca1e6bd4515559a054", &
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"7b2dd815e5991f88d14", &
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"bfde5ebc6e09940460c", &
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"487f5ffeaf139c209f4", &
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"08d6b3c9686cc0f6ff4", &
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"e198f5466141f53ab84", &
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"0a7c7af0ac612d14f40", &
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"a4192113ec53f4d165c", &
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"1423ae72e003614be88"/
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288
lib/fsk4hf/ldpc_174_74_parity.f90
Normal file
288
lib/fsk4hf/ldpc_174_74_parity.f90
Normal file
@ -0,0 +1,288 @@
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! parity check matrix for regular column weight 3 (174,74) LDPC code
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data Mn/ &
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28, 32, 98, &
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1, 94, 95, &
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70, 71, 94, &
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3, 9, 39, &
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4, 22, 84, &
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5, 25, 85, &
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6, 55, 100, &
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7, 41, 67, &
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8, 62, 77, &
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10, 37, 40, &
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11, 16, 36, &
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12, 29, 47, &
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14, 57, 91, &
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15, 49, 59, &
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17, 18, 52, &
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19, 48, 58, &
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20, 34, 72, &
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21, 38, 87, &
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23, 46, 79, &
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24, 43, 83, &
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26, 74, 78, &
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27, 51, 98, &
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30, 35, 42, &
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31, 63, 88, &
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25, 33, 82, &
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44, 53, 96, &
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50, 75, 90, &
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46, 54, 71, &
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56, 76, 81, &
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60, 65, 69, &
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61, 95, 97, &
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64, 89, 99, &
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66, 73, 76, &
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68, 80, 92, &
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74, 86, 87, &
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52, 55, 93, &
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1, 3, 21, &
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2, 57, 64, &
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4, 11, 82, &
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5, 60, 81, &
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6, 13, 66, &
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7, 43, 59, &
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8, 27, 85, &
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9, 34, 94, &
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10, 28, 88, &
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12, 19, 53, &
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14, 33, 65, &
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15, 75, 84, &
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||||||
|
16, 56, 68, &
|
||||||
|
17, 44, 90, &
|
||||||
|
18, 23, 73, &
|
||||||
|
20, 26, 83, &
|
||||||
|
22, 42, 91, &
|
||||||
|
24, 70, 79, &
|
||||||
|
29, 96, 97, &
|
||||||
|
30, 48, 77, &
|
||||||
|
31, 37, 67, &
|
||||||
|
32, 35, 78, &
|
||||||
|
36, 80, 89, &
|
||||||
|
38, 62, 93, &
|
||||||
|
39, 54, 72, &
|
||||||
|
40, 58, 61, &
|
||||||
|
41, 51, 86, &
|
||||||
|
9, 45, 63, &
|
||||||
|
46, 47, 92, &
|
||||||
|
49, 50, 80, &
|
||||||
|
69, 75, 98, &
|
||||||
|
14, 71, 99, &
|
||||||
|
21, 85, 100, &
|
||||||
|
1, 6, 50, &
|
||||||
|
2, 74, 98, &
|
||||||
|
3, 73, 92, &
|
||||||
|
4, 32, 79, &
|
||||||
|
5, 63, 96, &
|
||||||
|
1, 29, 79, &
|
||||||
|
2, 6, 84, &
|
||||||
|
3, 36, 78, &
|
||||||
|
4, 59, 69, &
|
||||||
|
5, 72, 80, &
|
||||||
|
2, 41, 44, &
|
||||||
|
7, 38, 90, &
|
||||||
|
8, 58, 99, &
|
||||||
|
9, 42, 49, &
|
||||||
|
10, 46, 74, &
|
||||||
|
11, 14, 73, &
|
||||||
|
12, 85, 88, &
|
||||||
|
13, 25, 93, &
|
||||||
|
5, 11, 61, &
|
||||||
|
15, 16, 94, &
|
||||||
|
8, 15, 32, &
|
||||||
|
17, 64, 76, &
|
||||||
|
18, 60, 71, &
|
||||||
|
19, 34, 57, &
|
||||||
|
20, 77, 96, &
|
||||||
|
21, 31, 82, &
|
||||||
|
22, 23, 48, &
|
||||||
|
16, 17, 22, &
|
||||||
|
24, 35, 86, &
|
||||||
|
13, 51, 64, &
|
||||||
|
26, 33, 39, &
|
||||||
|
4, 27, 47, &
|
||||||
|
28, 54, 56, &
|
||||||
|
1, 62, 76, &
|
||||||
|
30, 53, 100, &
|
||||||
|
21, 46, 57, &
|
||||||
|
32, 55, 61, &
|
||||||
|
33, 92, 95, &
|
||||||
|
19, 67, 68, &
|
||||||
|
14, 35, 75, &
|
||||||
|
3, 84, 99, &
|
||||||
|
37, 75, 92, &
|
||||||
|
7, 30, 63, &
|
||||||
|
23, 39, 50, &
|
||||||
|
27, 40, 44, &
|
||||||
|
41, 66, 91, &
|
||||||
|
9, 10, 69, &
|
||||||
|
12, 43, 52, &
|
||||||
|
6, 20, 88, &
|
||||||
|
43, 45, 89, &
|
||||||
|
24, 31, 60, &
|
||||||
|
47, 50, 70, &
|
||||||
|
26, 38, 45, &
|
||||||
|
25, 42, 98, &
|
||||||
|
40, 79, 87, &
|
||||||
|
51, 68, 83, &
|
||||||
|
52, 97, 98, &
|
||||||
|
48, 71, 78, &
|
||||||
|
28, 29, 80, &
|
||||||
|
53, 59, 73, &
|
||||||
|
49, 54, 95, &
|
||||||
|
34, 36, 90, &
|
||||||
|
55, 82, 89, &
|
||||||
|
4, 77, 90, &
|
||||||
|
49, 58, 81, &
|
||||||
|
18, 56, 77, &
|
||||||
|
62, 63, 65, &
|
||||||
|
60, 91, 100, &
|
||||||
|
2, 11, 62, &
|
||||||
|
15, 24, 93, &
|
||||||
|
37, 66, 83, &
|
||||||
|
65, 85, 86, &
|
||||||
|
5, 10, 48, &
|
||||||
|
1, 69, 89, &
|
||||||
|
67, 81, 87, &
|
||||||
|
13, 56, 75, &
|
||||||
|
70, 72, 97, &
|
||||||
|
8, 50, 57, &
|
||||||
|
6, 19, 33, &
|
||||||
|
7, 25, 99, &
|
||||||
|
74, 94, 96, &
|
||||||
|
14, 52, 87, &
|
||||||
|
16, 30, 40, &
|
||||||
|
20, 42, 79, &
|
||||||
|
17, 21, 72, &
|
||||||
|
9, 12, 41, &
|
||||||
|
18, 61, 67, &
|
||||||
|
3, 83, 97, &
|
||||||
|
26, 80, 91, &
|
||||||
|
23, 55, 65, &
|
||||||
|
27, 31, 95, &
|
||||||
|
28, 84, 86, &
|
||||||
|
29, 34, 93, &
|
||||||
|
46, 51, 63, &
|
||||||
|
35, 39, 76, &
|
||||||
|
13, 44, 78, &
|
||||||
|
32, 37, 38, &
|
||||||
|
22, 43, 92, &
|
||||||
|
45, 53, 54, &
|
||||||
|
58, 73, 74, &
|
||||||
|
47, 64, 100, &
|
||||||
|
59, 68, 85, &
|
||||||
|
66, 82, 96, &
|
||||||
|
36, 81, 88, &
|
||||||
|
2, 45, 70/
|
||||||
|
|
||||||
|
data Nm/ &
|
||||||
|
2, 37, 70, 75, 103, 143, &
|
||||||
|
38, 71, 76, 80, 138, 174, &
|
||||||
|
4, 37, 72, 77, 110, 157, &
|
||||||
|
5, 39, 73, 78, 101, 133, &
|
||||||
|
6, 40, 74, 79, 88, 142, &
|
||||||
|
7, 41, 70, 76, 118, 148, &
|
||||||
|
8, 42, 81, 112, 149, 0, &
|
||||||
|
9, 43, 82, 90, 147, 0, &
|
||||||
|
4, 44, 64, 83, 116, 155, &
|
||||||
|
10, 45, 84, 116, 142, 0, &
|
||||||
|
11, 39, 85, 88, 138, 0, &
|
||||||
|
12, 46, 86, 117, 155, 0, &
|
||||||
|
41, 87, 99, 145, 165, 0, &
|
||||||
|
13, 47, 68, 85, 109, 151, &
|
||||||
|
14, 48, 89, 90, 139, 0, &
|
||||||
|
11, 49, 89, 97, 152, 0, &
|
||||||
|
15, 50, 91, 97, 154, 0, &
|
||||||
|
15, 51, 92, 135, 156, 0, &
|
||||||
|
16, 46, 93, 108, 148, 0, &
|
||||||
|
17, 52, 94, 118, 153, 0, &
|
||||||
|
18, 37, 69, 95, 105, 154, &
|
||||||
|
5, 53, 96, 97, 167, 0, &
|
||||||
|
19, 51, 96, 113, 159, 0, &
|
||||||
|
20, 54, 98, 120, 139, 0, &
|
||||||
|
6, 25, 87, 123, 149, 0, &
|
||||||
|
21, 52, 100, 122, 158, 0, &
|
||||||
|
22, 43, 101, 114, 160, 0, &
|
||||||
|
1, 45, 102, 128, 161, 0, &
|
||||||
|
12, 55, 75, 128, 162, 0, &
|
||||||
|
23, 56, 104, 112, 152, 0, &
|
||||||
|
24, 57, 95, 120, 160, 0, &
|
||||||
|
1, 58, 73, 90, 106, 166, &
|
||||||
|
25, 47, 100, 107, 148, 0, &
|
||||||
|
17, 44, 93, 131, 162, 0, &
|
||||||
|
23, 58, 98, 109, 164, 0, &
|
||||||
|
11, 59, 77, 131, 173, 0, &
|
||||||
|
10, 57, 111, 140, 166, 0, &
|
||||||
|
18, 60, 81, 122, 166, 0, &
|
||||||
|
4, 61, 100, 113, 164, 0, &
|
||||||
|
10, 62, 114, 124, 152, 0, &
|
||||||
|
8, 63, 80, 115, 155, 0, &
|
||||||
|
23, 53, 83, 123, 153, 0, &
|
||||||
|
20, 42, 117, 119, 167, 0, &
|
||||||
|
26, 50, 80, 114, 165, 0, &
|
||||||
|
64, 119, 122, 168, 174, 0, &
|
||||||
|
19, 28, 65, 84, 105, 163, &
|
||||||
|
12, 65, 101, 121, 170, 0, &
|
||||||
|
16, 56, 96, 127, 142, 0, &
|
||||||
|
14, 66, 83, 130, 134, 0, &
|
||||||
|
27, 66, 70, 113, 121, 147, &
|
||||||
|
22, 63, 99, 125, 163, 0, &
|
||||||
|
15, 36, 117, 126, 151, 0, &
|
||||||
|
26, 46, 104, 129, 168, 0, &
|
||||||
|
28, 61, 102, 130, 168, 0, &
|
||||||
|
7, 36, 106, 132, 159, 0, &
|
||||||
|
29, 49, 102, 135, 145, 0, &
|
||||||
|
13, 38, 93, 105, 147, 0, &
|
||||||
|
16, 62, 82, 134, 169, 0, &
|
||||||
|
14, 42, 78, 129, 171, 0, &
|
||||||
|
30, 40, 92, 120, 137, 0, &
|
||||||
|
31, 62, 88, 106, 156, 0, &
|
||||||
|
9, 60, 103, 136, 138, 0, &
|
||||||
|
24, 64, 74, 112, 136, 163, &
|
||||||
|
32, 38, 91, 99, 170, 0, &
|
||||||
|
30, 47, 136, 141, 159, 0, &
|
||||||
|
33, 41, 115, 140, 172, 0, &
|
||||||
|
8, 57, 108, 144, 156, 0, &
|
||||||
|
34, 49, 108, 125, 171, 0, &
|
||||||
|
30, 67, 78, 116, 143, 0, &
|
||||||
|
3, 54, 121, 146, 174, 0, &
|
||||||
|
3, 28, 68, 92, 127, 0, &
|
||||||
|
17, 61, 79, 146, 154, 0, &
|
||||||
|
33, 51, 72, 85, 129, 169, &
|
||||||
|
21, 35, 71, 84, 150, 169, &
|
||||||
|
27, 48, 67, 109, 111, 145, &
|
||||||
|
29, 33, 91, 103, 164, 0, &
|
||||||
|
9, 56, 94, 133, 135, 0, &
|
||||||
|
21, 58, 77, 127, 165, 0, &
|
||||||
|
19, 54, 73, 75, 124, 153, &
|
||||||
|
34, 59, 66, 79, 128, 158, &
|
||||||
|
29, 40, 134, 144, 173, 0, &
|
||||||
|
25, 39, 95, 132, 172, 0, &
|
||||||
|
20, 52, 125, 140, 157, 0, &
|
||||||
|
5, 48, 76, 110, 161, 0, &
|
||||||
|
6, 43, 69, 86, 141, 171, &
|
||||||
|
35, 63, 98, 141, 161, 0, &
|
||||||
|
18, 35, 124, 144, 151, 0, &
|
||||||
|
24, 45, 86, 118, 173, 0, &
|
||||||
|
32, 59, 119, 132, 143, 0, &
|
||||||
|
27, 50, 81, 131, 133, 0, &
|
||||||
|
13, 53, 115, 137, 158, 0, &
|
||||||
|
34, 65, 72, 107, 111, 167, &
|
||||||
|
36, 60, 87, 139, 162, 0, &
|
||||||
|
2, 3, 44, 89, 150, 0, &
|
||||||
|
2, 31, 107, 130, 160, 0, &
|
||||||
|
26, 55, 74, 94, 150, 172, &
|
||||||
|
31, 55, 126, 146, 157, 0, &
|
||||||
|
1, 22, 67, 71, 123, 126, &
|
||||||
|
32, 68, 82, 110, 149, 0, &
|
||||||
|
7, 69, 104, 137, 170, 0/
|
||||||
|
|
||||||
|
data nrw/ &
|
||||||
|
6,6,6,6,6,6,5,5,6,5,5,5,5,6,5,5,5,5,5,5, &
|
||||||
|
6,5,5,5,5,5,5,5,5,5,5,6,5,5,5,5,5,5,5,5, &
|
||||||
|
5,5,5,5,5,6,5,5,5,6,5,5,5,5,5,5,5,5,5,5, &
|
||||||
|
5,5,6,5,5,5,5,5,5,5,5,5,6,6,6,5,5,5,6,6, &
|
||||||
|
5,5,5,5,6,5,5,5,5,5,5,6,5,5,5,6,5,6,5,5/
|
||||||
|
|
||||||
|
ncw=3
|
144
lib/fsk4hf/ldpcsim174_74.f90
Normal file
144
lib/fsk4hf/ldpcsim174_74.f90
Normal file
@ -0,0 +1,144 @@
|
|||||||
|
program ldpcsim174_74
|
||||||
|
|
||||||
|
! End-to-end test of the (174,74)/crc24 encoder and decoders.
|
||||||
|
|
||||||
|
use crc
|
||||||
|
use packjt
|
||||||
|
|
||||||
|
parameter(N=174, K=74, M=N-K)
|
||||||
|
character*8 arg
|
||||||
|
character*50 cmsg
|
||||||
|
character*24 c24
|
||||||
|
integer*1 msgbits(74)
|
||||||
|
integer*1 apmask(174)
|
||||||
|
integer*1 cw(174)
|
||||||
|
integer*1 codeword(N),message(50)
|
||||||
|
integer ncrc24
|
||||||
|
integer nerrtot(174),nerrdec(174),nmpcbad(74)
|
||||||
|
real rxdata(N),llr(N)
|
||||||
|
real dllr(174),llrd(174)
|
||||||
|
|
||||||
|
data cmsg/'11111111000000001111111100000000111111110000000011'/
|
||||||
|
|
||||||
|
nerrtot=0
|
||||||
|
nerrdec=0
|
||||||
|
nmpcbad=0 ! Used to collect the number of errors in the message+crc part of the codeword
|
||||||
|
|
||||||
|
nargs=iargc()
|
||||||
|
if(nargs.ne.5) then
|
||||||
|
print*,'Usage: ldpcsim niter ndeep #trials s K'
|
||||||
|
print*,'e.g. ldpcsim174_74 20 5 1000 0.85 64'
|
||||||
|
print*,'s : if negative, then value is ignored and sigma is calculated from SNR.'
|
||||||
|
print*,'niter: is the number of BP iterations.'
|
||||||
|
print*,'ndeep: -1 is BP only, ndeep>=0 is OSD order'
|
||||||
|
print*,'K :is the number of message+CRC bits and must be in the range [50,74]'
|
||||||
|
return
|
||||||
|
endif
|
||||||
|
call getarg(1,arg)
|
||||||
|
read(arg,*) max_iterations
|
||||||
|
call getarg(2,arg)
|
||||||
|
read(arg,*) ndeep
|
||||||
|
call getarg(3,arg)
|
||||||
|
read(arg,*) ntrials
|
||||||
|
call getarg(4,arg)
|
||||||
|
read(arg,*) s
|
||||||
|
call getarg(5,arg)
|
||||||
|
read(arg,*) Keff
|
||||||
|
|
||||||
|
rate=real(Keff)/real(N)
|
||||||
|
|
||||||
|
write(*,*) "code rate: ",rate
|
||||||
|
write(*,*) "niter : ",max_iterations
|
||||||
|
write(*,*) "ndeep : ",ndeep
|
||||||
|
write(*,*) "s : ",s
|
||||||
|
write(*,*) "K : ",Keff
|
||||||
|
|
||||||
|
msgbits=0
|
||||||
|
read(cmsg,'(50i1)') msgbits(1:50)
|
||||||
|
write(*,*) 'message'
|
||||||
|
write(*,'(74i1)') msgbits
|
||||||
|
|
||||||
|
call get_crc24(msgbits,ncrc24)
|
||||||
|
write(c24,'(b24.24)') ncrc24
|
||||||
|
read(c24,'(24i1)') msgbits(51:74)
|
||||||
|
call encode174_74(msgbits,codeword)
|
||||||
|
call init_random_seed()
|
||||||
|
call sgran()
|
||||||
|
|
||||||
|
write(*,*) 'codeword'
|
||||||
|
write(*,'(50i1,1x,24i1,1x,100i1)') codeword
|
||||||
|
|
||||||
|
write(*,*) "Eb/N0 Es/N0 ngood nundetected sigma symbol error rate"
|
||||||
|
do idb = 8,-3,-1
|
||||||
|
db=idb/2.0-1.0
|
||||||
|
sigma=1/sqrt( 2*rate*(10**(db/10.0)) ) ! to make db represent Eb/No
|
||||||
|
! sigma=1/sqrt( 2*(10**(db/10.0)) ) ! db represents Es/No
|
||||||
|
ngood=0
|
||||||
|
nue=0
|
||||||
|
nberr=0
|
||||||
|
do itrial=1, ntrials
|
||||||
|
! Create a realization of a noisy received word
|
||||||
|
do i=1,N
|
||||||
|
rxdata(i) = 2.0*codeword(i)-1.0 + sigma*gran()
|
||||||
|
enddo
|
||||||
|
nerr=0
|
||||||
|
do i=1,N
|
||||||
|
if( rxdata(i)*(2*codeword(i)-1.0) .lt. 0 ) nerr=nerr+1
|
||||||
|
enddo
|
||||||
|
if(nerr.ge.1) nerrtot(nerr)=nerrtot(nerr)+1
|
||||||
|
nberr=nberr+nerr
|
||||||
|
|
||||||
|
rxav=sum(rxdata)/N
|
||||||
|
rx2av=sum(rxdata*rxdata)/N
|
||||||
|
rxsig=sqrt(rx2av-rxav*rxav)
|
||||||
|
rxdata=rxdata/rxsig
|
||||||
|
! To match the metric to the channel, s should be set to the noise standard deviation.
|
||||||
|
! For now, set s to the value that optimizes decode probability near threshold.
|
||||||
|
! The s parameter can be tuned to trade a few tenth's dB of threshold for an order of
|
||||||
|
! magnitude in UER
|
||||||
|
if( s .lt. 0 ) then
|
||||||
|
ss=sigma
|
||||||
|
else
|
||||||
|
ss=s
|
||||||
|
endif
|
||||||
|
|
||||||
|
llr=2.0*rxdata/(ss*ss)
|
||||||
|
apmask=0
|
||||||
|
! max_iterations is max number of belief propagation iterations
|
||||||
|
call bpdecode174_74(llr,apmask,max_iterations,message,cw,nharderror,niterations)
|
||||||
|
dmin=0.0
|
||||||
|
if( (nharderror .lt. 0) .and. (ndeep .ge. 0) ) then
|
||||||
|
call osd174_74(llr, Keff, apmask, ndeep, message, cw, nharderror, dmin)
|
||||||
|
endif
|
||||||
|
|
||||||
|
if(nharderror.ge.0) then
|
||||||
|
n2err=0
|
||||||
|
do i=1,N
|
||||||
|
if( cw(i)*(2*codeword(i)-1.0) .lt. 0 ) n2err=n2err+1
|
||||||
|
enddo
|
||||||
|
if(n2err.eq.0) then
|
||||||
|
ngood=ngood+1
|
||||||
|
else
|
||||||
|
nue=nue+1
|
||||||
|
endif
|
||||||
|
endif
|
||||||
|
enddo
|
||||||
|
! snr2500=db+10*log10(200.0/116.0/2500.0)
|
||||||
|
esn0=db+10*log10(rate)
|
||||||
|
pberr=real(nberr)/(real(ntrials*N))
|
||||||
|
write(*,"(f4.1,4x,f5.1,1x,i8,1x,i8,8x,f5.2,8x,e10.3)") db,esn0,ngood,nue,ss,pberr
|
||||||
|
|
||||||
|
enddo
|
||||||
|
|
||||||
|
open(unit=23,file='nerrhisto.dat',status='unknown')
|
||||||
|
do i=1,120
|
||||||
|
write(23,'(i4,2x,i10,i10,f10.2)') i,nerrdec(i),nerrtot(i),real(nerrdec(i))/real(nerrtot(i)+1e-10)
|
||||||
|
enddo
|
||||||
|
close(23)
|
||||||
|
open(unit=25,file='nmpcbad.dat',status='unknown')
|
||||||
|
do i=1,68
|
||||||
|
write(25,'(i4,2x,i10)') i,nmpcbad(i)
|
||||||
|
enddo
|
||||||
|
close(25)
|
||||||
|
|
||||||
|
end program ldpcsim174_74
|
405
lib/fsk4hf/osd174_74.f90
Normal file
405
lib/fsk4hf/osd174_74.f90
Normal file
@ -0,0 +1,405 @@
|
|||||||
|
subroutine osd174_74(llr,k,apmask,ndeep,message74,cw,nhardmin,dmin)
|
||||||
|
!
|
||||||
|
! An ordered-statistics decoder for the (174,74) code.
|
||||||
|
! Message payload is 50 bits. Any or all of a 24-bit CRC can be
|
||||||
|
! used for detecting incorrect codewords. The remaining CRC bits are
|
||||||
|
! cascaded with the LDPC code for the purpose of improving the
|
||||||
|
! distance spectrum of the code.
|
||||||
|
!
|
||||||
|
! If p1 (0.le.p1.le.24) is the number of CRC24 bits that are
|
||||||
|
! to be used for bad codeword detection, then the argument k should
|
||||||
|
! be set to 50+p1.
|
||||||
|
!
|
||||||
|
! Valid values for k are in the range [50,74].
|
||||||
|
!
|
||||||
|
character*24 c24
|
||||||
|
integer, parameter:: N=174
|
||||||
|
integer*1 apmask(N),apmaskr(N)
|
||||||
|
integer*1, allocatable, save :: gen(:,:)
|
||||||
|
integer*1, allocatable :: genmrb(:,:),g2(:,:)
|
||||||
|
integer*1, allocatable :: temp(:),m0(:),me(:),mi(:),misub(:),e2sub(:),e2(:),ui(:)
|
||||||
|
integer*1, allocatable :: r2pat(:)
|
||||||
|
integer indices(N),nxor(N)
|
||||||
|
integer*1 cw(N),ce(N),c0(N),hdec(N)
|
||||||
|
integer*1, allocatable :: decoded(:)
|
||||||
|
integer*1 message50(50),message74(74)
|
||||||
|
integer indx(N)
|
||||||
|
real llr(N),rx(N),absrx(N)
|
||||||
|
|
||||||
|
!include "ldpc_174_74_generator.f90"
|
||||||
|
|
||||||
|
logical first,reset
|
||||||
|
data first/.true./
|
||||||
|
save first
|
||||||
|
|
||||||
|
allocate( genmrb(k,N), g2(N,k) )
|
||||||
|
allocate( temp(k), m0(k), me(k), mi(k), misub(k), e2sub(N-k), e2(N-k), ui(N-k) )
|
||||||
|
allocate( r2pat(N-k), decoded(k) )
|
||||||
|
|
||||||
|
if( first ) then ! fill the generator matrix
|
||||||
|
!
|
||||||
|
! Create generator matrix for partial CRC cascaded with LDPC code.
|
||||||
|
!
|
||||||
|
! Let p2=74-k and p1+p2=24.
|
||||||
|
!
|
||||||
|
! The last p2 bits of the CRC24 are cascaded with the LDPC code.
|
||||||
|
!
|
||||||
|
! The first p1=k-50 CRC24 bits will be used for error detection.
|
||||||
|
!
|
||||||
|
allocate( gen(k,N) )
|
||||||
|
gen=0
|
||||||
|
do i=1,k
|
||||||
|
message74=0
|
||||||
|
message74(i)=1
|
||||||
|
if(i.le.50) then
|
||||||
|
call get_crc24(message74,ncrc24)
|
||||||
|
write(c24,'(b24.24)') ncrc24
|
||||||
|
read(c24,'(24i1)') message74(51:74)
|
||||||
|
message74(51:k)=0
|
||||||
|
endif
|
||||||
|
call encode174_74(message74,cw)
|
||||||
|
gen(i,:)=cw
|
||||||
|
enddo
|
||||||
|
|
||||||
|
first=.false.
|
||||||
|
endif
|
||||||
|
|
||||||
|
rx=llr
|
||||||
|
apmaskr=apmask
|
||||||
|
|
||||||
|
! Hard decisions on the received word.
|
||||||
|
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)
|
||||||
|
|
||||||
|
! 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 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
|
||||||
|
enddo
|
||||||
|
exit
|
||||||
|
endif
|
||||||
|
enddo
|
||||||
|
enddo
|
||||||
|
|
||||||
|
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.
|
||||||
|
! 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.
|
||||||
|
|
||||||
|
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 mrbencode74(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.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
|
||||||
|
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=19
|
||||||
|
elseif(ndeep.eq.5) then
|
||||||
|
nord=3
|
||||||
|
npre1=1
|
||||||
|
npre2=1
|
||||||
|
nt=40
|
||||||
|
ntheta=12
|
||||||
|
ntau=19
|
||||||
|
elseif(ndeep.eq.6) then
|
||||||
|
nord=4
|
||||||
|
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 mrbencode74(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
|
||||||
|
e2=ieor(e2sub,g2(k+1:N,n1))
|
||||||
|
nd1kpt=sum(e2(1:nt))+2
|
||||||
|
endif
|
||||||
|
if(nd1kpt .le. ntheta) then
|
||||||
|
call mrbencode74(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
|
||||||
|
enddo
|
||||||
|
! Get the next test error pattern, iflag will go negative
|
||||||
|
! when the last pattern with weight iorder has been generated.
|
||||||
|
call nextpat74(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 boxit74(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 mrbencode74(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 fetchit74(reset,r2pat(1:ntau),ntau,in1,in2)
|
||||||
|
if(in1.gt.0.and.in2.gt.0) then
|
||||||
|
ncount2=ncount2+1
|
||||||
|
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
|
||||||
|
me=ieor(m0,mi)
|
||||||
|
call mrbencode74(me,ce,g2,N,k)
|
||||||
|
nxor=ieor(ce,hdec)
|
||||||
|
dd=sum(nxor*absrx)
|
||||||
|
if( dd .lt. dmin ) then
|
||||||
|
dmin=dd
|
||||||
|
cw=ce
|
||||||
|
nhardmin=sum(nxor)
|
||||||
|
endif
|
||||||
|
goto 778
|
||||||
|
endif
|
||||||
|
enddo
|
||||||
|
call nextpat74(misub,k,nord,iflag)
|
||||||
|
enddo
|
||||||
|
endif
|
||||||
|
|
||||||
|
998 continue
|
||||||
|
! Re-order the codeword to [message bits][parity bits] format.
|
||||||
|
cw(indices)=cw
|
||||||
|
hdec(indices)=hdec
|
||||||
|
message74=cw(1:74)
|
||||||
|
call get_crc24(message74,nbadcrc)
|
||||||
|
if(nbadcrc.ne.0) nhardmin=-nhardmin
|
||||||
|
|
||||||
|
return
|
||||||
|
end subroutine osd174_74
|
||||||
|
|
||||||
|
subroutine mrbencode74(me,codeword,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
|
||||||
|
end subroutine mrbencode74
|
||||||
|
|
||||||
|
subroutine nextpat74(mi,k,iorder,iflag)
|
||||||
|
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
|
||||||
|
end subroutine nextpat74
|
||||||
|
|
||||||
|
subroutine boxit74(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
|
||||||
|
|
||||||
|
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
|
||||||
|
|
||||||
|
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 boxit74
|
||||||
|
|
||||||
|
subroutine fetchit74(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
|
||||||
|
|
||||||
|
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)
|
||||||
|
|
||||||
|
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 fetchit74
|
||||||
|
|
Loading…
Reference in New Issue
Block a user