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Add routines necessary to support a crc24-aided (174,101) code.
This commit is contained in:
Steven Franke
parent
35eb391e23
commit
fae81b6b67
@ -606,10 +606,14 @@ set (wsjt_FSRCS
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# lib/ft8/decode174_91.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/ldpcsim174_101.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/encode174_101.f90
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lib/fsk4hf/bpdecode174_74.f90
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lib/fsk4hf/bpdecode174_101.f90
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lib/fsk4hf/osd174_74.f90
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lib/fsk4hf/osd174_101.f90
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lib/fsk4hf/wspr4sim.f90
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lib/fsk4hf/genwspr4.f90
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lib/fsk4hf/gen_wspr4wave.f90
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@ -1361,6 +1365,9 @@ target_link_libraries (ldpcsim174_91 wsjt_fort wsjt_cxx)
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add_executable (ldpcsim174_74 lib/fsk4hf/ldpcsim174_74.f90 wsjtx.rc)
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target_link_libraries (ldpcsim174_74 wsjt_fort wsjt_cxx)
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add_executable (ldpcsim174_101 lib/fsk4hf/ldpcsim174_101.f90 wsjtx.rc)
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target_link_libraries (ldpcsim174_101 wsjt_fort wsjt_cxx)
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add_executable (wspr4sim lib/fsk4hf/wspr4sim.f90 wsjtx.rc)
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target_link_libraries (wspr4sim wsjt_fort wsjt_cxx)
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113
lib/fsk4hf/bpdecode174_101.f90
Normal file
113
lib/fsk4hf/bpdecode174_101.f90
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@ -0,0 +1,113 @@
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subroutine bpdecode174_101(llr,apmask,maxiterations,message50,cw,nharderror,iter)
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!
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! A log-domain belief propagation decoder for the (174,101) code.
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!
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integer, parameter:: N=174, K=101, 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 nrw(M),ncw
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integer Nm(8,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(8,M)
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real tanhtoc(8,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_101_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(1:101)
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call get_crc24(decoded,101,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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message77=decoded(1:77)
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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(1:8,i)=tanh(-toc(1:8,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_101
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46
lib/fsk4hf/encode174_101.f90
Normal file
46
lib/fsk4hf/encode174_101.f90
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@ -0,0 +1,46 @@
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subroutine encode174_101(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=101, 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*4 ncrc24
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include "ldpc_174_101_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=1,26
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read(g(i)(j:j),"(Z1)") istr
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ibmax=4
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if(j.eq.26) ibmax=1
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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_101
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@ -54,7 +54,7 @@ subroutine genwspr4(msg0,ichk,msgsent,msgbits,i4tone)
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call unpack77(c77,0,msgsent,unpk77_success) !Unpack to get msgsent
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msgbits=0
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read(c77,'(50i1)') msgbits(1:50)
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call get_crc24(msgbits,ncrc24)
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call get_crc24(msgbits,74,ncrc24)
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write(c24,'(b24.24)') ncrc24
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read(c24,'(24i1)') msgbits(51:74)
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@ -1,19 +1,19 @@
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subroutine get_crc24(mc,ncrc)
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subroutine get_crc24(mc,len,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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! 1. To calculate 24-bit CRC, mc(1:len-24) is the message and mc(len-23: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 c24*24
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integer*1 mc(74),r(25),p(25)
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integer*1 mc(len)
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integer*1 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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do i=0,len-25
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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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140
lib/fsk4hf/ldpcsim174_101.f90
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140
lib/fsk4hf/ldpcsim174_101.f90
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@ -0,0 +1,140 @@
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program ldpcsim174_101
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! End-to-end test of the (174,101)/crc24 encoder and decoders.
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use packjt77
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parameter(N=174, K=101, M=N-K)
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character*8 arg
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character*37 msg0,msg
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character*77 c77
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character*50 cmsg
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character*24 c24
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integer*1 msgbits(101)
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integer*1 apmask(174)
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integer*1 cw(174)
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integer*1 codeword(N),message(77)
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integer ncrc24
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real rxdata(N),llr(N)
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real dllr(174),llrd(174)
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logical first,unpk77_success
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data first/.true./
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nargs=iargc()
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if(nargs.ne.5 .and. nargs.ne.6) then
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print*,'Usage: ldpcsim niter ndeep #trials s K [msg]'
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print*,'e.g. ldpcsim174_101 20 5 1000 0.85 91 "K9AN K1JT FN20"'
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print*,'s : if negative, then value is ignored and sigma is calculated from SNR.'
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print*,'niter: is the number of BP iterations.'
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print*,'ndeep: -1 is BP only, ndeep>=0 is OSD order'
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print*,'K :is the number of message+CRC bits and must be in the range [77,101]'
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print*,'WSPR-format message is optional'
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return
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endif
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call getarg(1,arg)
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read(arg,*) max_iterations
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call getarg(2,arg)
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read(arg,*) ndeep
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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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msg0='K9AN K1JT FN20 '
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if(nargs.eq.6) call getarg(6,msg0)
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call pack77(msg0,i3,n3,c77)
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cmsg=c77(1:77)
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rate=real(Keff)/real(N)
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write(*,*) "code rate: ",rate
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write(*,*) "niter : ",max_iterations
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write(*,*) "ndeep : ",ndeep
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write(*,*) "s : ",s
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write(*,*) "K : ",Keff
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msgbits=0
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read(cmsg,'(77i1)') msgbits(1:77)
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write(*,*) 'message'
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write(*,'(77i1)') msgbits
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call get_crc24(msgbits,101,ncrc24)
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write(c24,'(b24.24)') ncrc24
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read(c24,'(24i1)') msgbits(78:101)
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call encode174_101(msgbits,codeword)
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call init_random_seed()
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call sgran()
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write(*,*) 'codeword'
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write(*,'(50i1,1x,24i1,1x,100i1)') codeword
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write(*,*) "Eb/N0 Es/N0 ngood nundetected sigma symbol error rate"
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do idb = 8,-3,-1
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db=idb/2.0-1.0
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sigma=1/sqrt( 2*rate*(10**(db/10.0)) ) ! to make db represent Eb/No
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! sigma=1/sqrt( 2*(10**(db/10.0)) ) ! db represents Es/No
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ngood=0
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nue=0
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nberr=0
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do itrial=1, ntrials
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! Create a realization of a noisy received word
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do i=1,N
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rxdata(i) = 2.0*codeword(i)-1.0 + sigma*gran()
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enddo
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nerr=0
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do i=1,N
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if( rxdata(i)*(2*codeword(i)-1.0) .lt. 0 ) nerr=nerr+1
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enddo
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nberr=nberr+nerr
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rxav=sum(rxdata)/N
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rx2av=sum(rxdata*rxdata)/N
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rxsig=sqrt(rx2av-rxav*rxav)
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rxdata=rxdata/rxsig
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if( s .lt. 0 ) then
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ss=sigma
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else
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ss=s
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endif
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llr=2.0*rxdata/(ss*ss)
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apmask=0
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! max_iterations is max number of belief propagation iterations
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call bpdecode174_101(llr,apmask,max_iterations,message,cw,nharderror,niterations)
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dmin=0.0
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if( (nharderror .lt. 0) .and. (ndeep .ge. 0) ) then
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call osd174_101(llr, Keff, apmask, ndeep, message, cw, nharderror, dmin)
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endif
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if(nharderror.ge.0) then
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n2err=0
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do i=1,N
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if( cw(i)*(2*codeword(i)-1.0) .lt. 0 ) n2err=n2err+1
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enddo
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if(n2err.eq.0) then
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ngood=ngood+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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enddo
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! snr2500=db+10*log10(200.0/116.0/2500.0)
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esn0=db+10*log10(rate)
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pberr=real(nberr)/(real(ntrials*N))
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write(*,"(f4.1,4x,f5.1,1x,i8,1x,i8,8x,f5.2,8x,e10.3)") db,esn0,ngood,nue,ss,pberr
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if(first) then
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write(c77,'(77i1)') message
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call unpack77(c77,0,msg,unpk77_success)
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if(unpk77_success) then
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write(*,1100) msg(1:37)
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1100 format('Decoded message: ',a37)
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else
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print*,'Error unpacking message'
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endif
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first=.false.
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endif
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enddo
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end program ldpcsim174_101
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@ -64,7 +64,7 @@ program ldpcsim174_74
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write(*,*) 'message'
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write(*,'(74i1)') msgbits
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call get_crc24(msgbits,ncrc24)
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call get_crc24(msgbits,74,ncrc24)
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write(c24,'(b24.24)') ncrc24
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read(c24,'(24i1)') msgbits(51:74)
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call encode174_74(msgbits,codeword)
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403
lib/fsk4hf/osd174_101.f90
Normal file
403
lib/fsk4hf/osd174_101.f90
Normal file
@ -0,0 +1,403 @@
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subroutine osd174_101(llr,k,apmask,ndeep,message101,cw,nhardmin,dmin)
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!
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! An ordered-statistics decoder for the (174,101) code.
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! Message payload is 77 bits. Any or all of a 24-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.24) is the number of CRC24 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 [77,101].
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!
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character*24 c24
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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 message77(77),message101(101)
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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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! Let p2=101-k and p1+p2=24.
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!
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! The last p2 bits of the CRC24 are cascaded with the LDPC code.
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!
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! The first p1=k-77 CRC24 bits will be used for error detection.
|
||||
!
|
||||
allocate( gen(k,N) )
|
||||
gen=0
|
||||
do i=1,k
|
||||
message101=0
|
||||
message101(i)=1
|
||||
if(i.le.77) then
|
||||
call get_crc24(message101,101,ncrc24)
|
||||
write(c24,'(b24.24)') ncrc24
|
||||
read(c24,'(24i1)') message101(78:101)
|
||||
message101(78:k)=0
|
||||
endif
|
||||
call encode174_101(message101,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 mrbencode101(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 mrbencode101(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 mrbencode101(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 nextpat101(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 boxit101(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 mrbencode101(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 fetchit101(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 mrbencode101(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 nextpat101(misub,k,nord,iflag)
|
||||
enddo
|
||||
endif
|
||||
|
||||
998 continue
|
||||
! Re-order the codeword to [message bits][parity bits] format.
|
||||
cw(indices)=cw
|
||||
hdec(indices)=hdec
|
||||
message101=cw(1:101)
|
||||
call get_crc24(message101,101,nbadcrc)
|
||||
if(nbadcrc.ne.0) nhardmin=-nhardmin
|
||||
|
||||
return
|
||||
end subroutine osd174_101
|
||||
|
||||
subroutine mrbencode101(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 mrbencode101
|
||||
|
||||
subroutine nextpat101(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 nextpat101
|
||||
|
||||
subroutine boxit101(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 boxit101
|
||||
|
||||
subroutine fetchit101(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 fetchit101
|
||||
|
||||
@ -52,7 +52,7 @@ subroutine osd174_74(llr,k,apmask,ndeep,message74,cw,nhardmin,dmin)
|
||||
message74=0
|
||||
message74(i)=1
|
||||
if(i.le.50) then
|
||||
call get_crc24(message74,ncrc24)
|
||||
call get_crc24(message74,74,ncrc24)
|
||||
write(c24,'(b24.24)') ncrc24
|
||||
read(c24,'(24i1)') message74(51:74)
|
||||
message74(51:k)=0
|
||||
@ -282,7 +282,7 @@ subroutine osd174_74(llr,k,apmask,ndeep,message74,cw,nhardmin,dmin)
|
||||
cw(indices)=cw
|
||||
hdec(indices)=hdec
|
||||
message74=cw(1:74)
|
||||
call get_crc24(message74,nbadcrc)
|
||||
call get_crc24(message74,74,nbadcrc)
|
||||
if(nbadcrc.ne.0) nhardmin=-nhardmin
|
||||
|
||||
return
|
||||
|
||||
@ -58,9 +58,7 @@ program wspr4d
|
||||
open(13,file=trim(data_dir)//'/ALL_WSPR.TXT',status='unknown', &
|
||||
position='append')
|
||||
|
||||
nav=0
|
||||
ngood=0
|
||||
ngood=0
|
||||
do ifile=iarg,nargs
|
||||
call getarg(ifile,infile)
|
||||
open(10,file=infile,status='old',access='stream')
|
||||
@ -89,14 +87,14 @@ ngood=0
|
||||
call getcandidate4(c2,npts,fs,fa,fb,ncand,candidates) !First approx for freq
|
||||
|
||||
ndecodes=0
|
||||
do icand=1,1
|
||||
do icand=1,ncand
|
||||
fc0=candidates(icand,1)
|
||||
xsnr=candidates(icand,2)
|
||||
xmax=-1e32
|
||||
smax=0.0
|
||||
fc1=fc0-1.50*(fs/416.0)
|
||||
do if=-20,20
|
||||
df=if*0.02
|
||||
df=if*0.04
|
||||
fc=fc1+df
|
||||
do is=300,450,5
|
||||
call coherent_sync(c2,is,fc,1,sync)
|
||||
|
||||
Loading…
Reference in New Issue
Block a user