diff --git a/CMakeLists.txt b/CMakeLists.txt index 2a17b5e98..265270a62 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -421,6 +421,7 @@ set (wsjt_FSRCS lib/extractmessage144.f90 lib/fsk4hf/extractmessage168.f90 lib/ft8/extractmessage174.f90 + lib/fsk4hf/extractmessage174_91.f90 lib/fano232.f90 lib/fast9.f90 lib/fast_decode.f90 @@ -530,6 +531,7 @@ set (wsjt_FSRCS lib/fsk4hf/msksoftsym.f90 lib/fsk4hf/msksoftsymw.f90 lib/ft8/osd174.f90 + lib/fsk4hf/osd174_91.f90 lib/fsk4hf/osd300.f90 lib/fsk4hf/osd204.f90 lib/pctile.f90 diff --git a/lib/fsk4hf/bpdecode174_91.f90 b/lib/fsk4hf/bpdecode174_91.f90 index 740e3175a..01f5fbe49 100644 --- a/lib/fsk4hf/bpdecode174_91.f90 +++ b/lib/fsk4hf/bpdecode174_91.f90 @@ -374,7 +374,7 @@ do iter=0,maxiterations ! send messages from check nodes to variable nodes do i=1,M - tanhtoc(1:6,i)=tanh(-toc(1:6,i)/2) + tanhtoc(1:7,i)=tanh(-toc(1:7,i)/2) enddo do j=1,N diff --git a/lib/fsk4hf/ldpc_174_91_a_params.f90 b/lib/fsk4hf/ldpc_174_91_a_params.f90 index 4001d5746..dd44be23e 100644 --- a/lib/fsk4hf/ldpc_174_91_a_params.f90 +++ b/lib/fsk4hf/ldpc_174_91_a_params.f90 @@ -1,5 +1,5 @@ integer, parameter:: N=174, K=91, M=N-K -character*22 g(83) +character*23 g(83) integer colorder(N) data g/ & diff --git a/lib/fsk4hf/ldpcsim174_91.f90 b/lib/fsk4hf/ldpcsim174_91.f90 index 5276fd8c3..aecea0bdd 100644 --- a/lib/fsk4hf/ldpcsim174_91.f90 +++ b/lib/fsk4hf/ldpcsim174_91.f90 @@ -1,5 +1,5 @@ program ldpcsim174_91 -! End to end test of the (174,77)/crc14 encoder and decoder. +! End to end test of the (174,91)/crc14 encoder and decoder. use crc use packjt @@ -7,14 +7,14 @@ character*22 msg,msgsent,msgreceived character*8 arg character*6 grid integer*1, allocatable :: codeword(:), decoded(:), message(:) -integer*1, target:: i1Msg8BitBytes(11) +integer*1, target:: i1Msg8BitBytes(12) integer*1 msgbits(91) integer*1 apmask(174), cw(174) integer*2 checksum integer*4 i4Msg6BitWords(13) integer colorder(174) integer nerrtot(174),nerrdec(174),nmpcbad(91) -logical checksumok,fsk,bpsk +logical checksumok real*8, allocatable :: rxdata(:) real, allocatable :: llr(:) @@ -50,9 +50,6 @@ read(arg,*) ntrials call getarg(4,arg) read(arg,*) s -fsk=.false. -bpsk=.true. - ! don't count crc bits as data bits N=174 K=91 @@ -89,18 +86,18 @@ allocate ( rxdata(N), llr(N) ) enddo enddo - i1Msg8BitBytes(10:11)=0 - checksum = crc14 (c_loc (i1Msg8BitBytes), 11) + i1Msg8BitBytes(10:12)=0 + checksum = crc14 (c_loc (i1Msg8BitBytes), 12) ! For reference, the next 3 lines show how to check the CRC - i1Msg8BitBytes(10)=checksum/256 - i1Msg8BitBytes(11)=iand (checksum,255) - checksumok = crc14_check(c_loc (i1Msg8BitBytes), 11) + i1Msg8BitBytes(11)=checksum/256 + i1Msg8BitBytes(12)=iand (checksum,255) + checksumok = crc14_check(c_loc (i1Msg8BitBytes), 12) if( checksumok ) write(*,*) 'Good checksum' -! K=87, For now: +! K=91, For now: ! msgbits(1:72) JT message bits -! msgbits(73:75) 3 free message bits (set to 0) -! msgbits(76:87) CRC12 +! msgbits(73:77) 5 free message bits (set to 0) +! msgbits(78:91) CRC14 mbit=0 do i=1, 9 i1=i1Msg8BitBytes(i) @@ -109,20 +106,20 @@ allocate ( rxdata(N), llr(N) ) msgbits(mbit)=iand(1,ishft(i1,ibit-8)) enddo enddo - msgbits(73:75)=0 ! the three extra message bits go here - i1=i1Msg8BitBytes(10) ! First 4 bits of crc12 are LSB of this byte - do ibit=1,4 - msgbits(75+ibit)=iand(1,ishft(i1,ibit-4)) + msgbits(73:77)=0 ! the five extra message bits go here + i1=i1Msg8BitBytes(11) ! First 6 bits of crc12 are LSB of this byte + do ibit=1,6 + msgbits(77+ibit)=iand(1,ishft(i1,ibit-6)) enddo - i1=i1Msg8BitBytes(11) ! Now shift in last 8 bits of the CRC + i1=i1Msg8BitBytes(12) ! Now shift in last 8 bits of the CRC do ibit=1,8 - msgbits(79+ibit)=iand(1,ishft(i1,ibit-8)) + msgbits(83+ibit)=iand(1,ishft(i1,ibit-8)) enddo write(*,*) 'message' - write(*,'(11(8i1,1x))') msgbits + write(*,'(12(8i1,1x))') msgbits - call encode174(msgbits,codeword) + call encode174_91(msgbits,codeword) call init_random_seed() ! call sgran() @@ -131,7 +128,7 @@ allocate ( rxdata(N), llr(N) ) write(*,*) "Es/N0 SNR2500 ngood nundetected nbadcrc sigma" do idb = 20,-10,-1 -!do idb = -3,-3,-1 +!do idb = 0,0,-1 db=idb/2.0-1.0 sigma=1/sqrt( 2*(10**(db/10.0)) ) ngood=0 @@ -141,20 +138,7 @@ do idb = 20,-10,-1 do itrial=1, ntrials ! Create a realization of a noisy received word do i=1,N - if( bpsk ) then - rxdata(i) = 2.0*codeword(i)-1.0 + sigma*gran() - elseif( fsk ) then - if( codeword(i) .eq. 1 ) then - r1=(1.0 + sigma*gran())**2 + (sigma*gran())**2 - r2=(sigma*gran())**2 + (sigma*gran())**2 - elseif( codeword(i) .eq. 0 ) then - r2=(1.0 + sigma*gran())**2 + (sigma*gran())**2 - r1=(sigma*gran())**2 + (sigma*gran())**2 - endif -! rxdata(i)=0.35*(sqrt(r1)-sqrt(r2)) -! rxdata(i)=0.35*(exp(r1)-exp(r2)) - rxdata(i)=0.12*(log(r1)-log(r2)) - endif + rxdata(i) = 2.0*codeword(i)-1.0 + sigma*gran() enddo nerr=0 do i=1,N @@ -163,15 +147,10 @@ do idb = 20,-10,-1 if(nerr.ge.1) nerrtot(nerr)=nerrtot(nerr)+1 nberr=nberr+nerr -! Correct signal normalization is important for this decoder. 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 @@ -180,16 +159,16 @@ do idb = 20,-10,-1 llr=2.0*rxdata/(ss*ss) nap=0 ! number of AP bits - llr(colorder(174-87+1:174-87+nap)+1)=5*(2.0*msgbits(1:nap)-1.0) + llr(colorder(174-91+1:174-91+nap)+1)=5*(2.0*msgbits(1:nap)-1.0) apmask=0 - apmask(colorder(174-87+1:174-87+nap)+1)=1 + apmask(colorder(174-91+1:174-91+nap)+1)=1 ! max_iterations is max number of belief propagation iterations - call bpdecode174(llr, apmask, max_iterations, decoded, cw, nharderrors,niterations) - if( ndepth .ge. 0 .and. nharderrors .lt. 0 ) call osd174(llr, apmask, ndepth, decoded, cw, nharderrors, dmin) + call bpdecode174_91(llr, apmask, max_iterations, decoded, cw, nharderrors,niterations) + if( ndepth .ge. 0 .and. nharderrors .lt. 0 ) call osd174_91(llr, apmask, ndepth, decoded, cw, nharderrors, dmin) ! If the decoder finds a valid codeword, nharderrors will be .ge. 0. if( nharderrors .ge. 0 ) then - call extractmessage174(decoded,msgreceived,ncrcflag) + call extractmessage174_91(decoded,msgreceived,ncrcflag) if( ncrcflag .ne. 1 ) then nbadcrc=nbadcrc+1 endif diff --git a/lib/fsk4hf/osd174_91.f90 b/lib/fsk4hf/osd174_91.f90 index 091214444..a48fbe412 100644 --- a/lib/fsk4hf/osd174_91.f90 +++ b/lib/fsk4hf/osd174_91.f90 @@ -21,12 +21,14 @@ save first,gen if( first ) then ! fill the generator matrix gen=0 do i=1,M - do j=1,22 + do j=1,23 read(g(i)(j:j),"(Z1)") istr - do jj=1, 4 - irow=(j-1)*4+jj - if( btest(istr,4-jj) ) gen(irow,i)=1 - enddo + ibmax=4 + if(j.eq.23) ibmax=3 + do jj=1, ibmax + irow=(j-1)*4+jj + if( btest(istr,4-jj) ) gen(irow,i)=1 + enddo enddo enddo do irow=1,K @@ -246,7 +248,7 @@ hdec(indices)=hdec decoded=cw(M+1:N) cw(colorder+1)=cw ! put the codeword back into received-word order return -end subroutine osd174 +end subroutine osd174_91 subroutine mrbencode(me,codeword,g2,N,K) integer*1 me(K),codeword(N),g2(N,K) @@ -291,7 +293,7 @@ end subroutine nextpat subroutine boxit(reset,e2,ntau,npindex,i1,i2) integer*1 e2(1:ntau) - integer indexes(4000,2),fp(0:525000),np(4000) + integer indexes(5000,2),fp(0:525000),np(5000) logical reset common/boxes/indexes,fp,np @@ -326,7 +328,7 @@ subroutine boxit(reset,e2,ntau,npindex,i1,i2) end subroutine boxit subroutine fetchit(reset,e2,ntau,i1,i2) - integer indexes(4000,2),fp(0:525000),np(4000) + integer indexes(5000,2),fp(0:525000),np(5000) integer lastpat integer*1 e2(ntau) logical reset