Add early termination code to the msk144 long-message decoder. Remove references to Radford Neal's ldpc code, which served us well but is no longer needed.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7051 ab8295b8-cf94-4d9e-aec4-7959e3be5d79

CMakeLists.txt

@@ -481,22 +481,6 @@ set (ka9q_CSRCS
   )
 set_source_files_properties (${ka9q_CSRCS} PROPERTIES COMPILE_FLAGS -Wno-sign-compare)
 
-set (ldpc_CSRCS
-  lib/ldpc/alloc.c
-  lib/ldpc/rcode.c
-  lib/ldpc/dec.c
-  lib/ldpc/enc.c
-  lib/ldpc/intio.c
-  lib/ldpc/blockio.c
-  lib/ldpc/check.c
-  lib/ldpc/encode.c
-  lib/ldpc/open.c
-  lib/ldpc/mod2dense.c
-  lib/ldpc/mod2sparse.c
-  lib/ldpc/mod2convert.c
-  lib/ldpc/distrib.c
-  )
-
 set (qra_CSRCS
   lib/qra/qra64/qra64.c
   lib/qra/qra64/qra64_subs.c
@@ -1245,10 +1229,6 @@ install (FILES
 
 install (FILES
   contrib/Ephemeris/JPLEPH
-  contrib/LDPC/peg-128-80-reg3.gen
-  contrib/LDPC/peg-128-80-reg3.pchk
-  contrib/LDPC/peg-32-16-reg3.gen
-  contrib/LDPC/peg-32-16-reg3.pchk
   DESTINATION ${WSJT_SHARE_DESTINATION}/${WSJT_DATA_DESTINATION}
   #COMPONENT runtime
   )

lib/bpdecode144.f90

@@ -276,6 +276,8 @@ do j=1,M
   enddo
 enddo
 
+ncnt=0
+
 do iter=0,maxiterations
 
 ! Update bit log likelihood ratios
@@ -299,6 +301,21 @@ do iter=0,maxiterations
     return
   endif
 
+  if( iter.gt.0 ) then  ! this code block implements an early stopping criterion
+    nd=ncheck-nclast
+    if( nd .lt. 0 ) then ! # of unsatisfied parity checks decreased
+      ncnt=0  ! reset counter
+    else
+      ncnt=ncnt+1
+    endif
+!    write(*,*) iter,ncheck,nd,ncnt
+    if( ncnt .ge. 3 .and. iter .ge. 5 .and. ncheck .gt. 10) then
+      niterations=-1
+      return
+    endif
+  endif
+  nclast=ncheck 
+ 
 ! Send messages from bits to check nodes 
   do j=1,M
     do i=1,nrw

lib/detectmsk144.f90

@@ -1,10 +1,9 @@
-subroutine detectmsk144(cbig,n,pchk_file,lines,nmessages,nutc,ntol,t00)
+subroutine detectmsk144(cbig,n,lines,nmessages,nutc,ntol,t00)
   use timer_module, only: timer
 
   parameter (NSPM=864, NPTS=3*NSPM, MAXSTEPS=1700, NFFT=NSPM, MAXCAND=16)
   character*22 msgreceived,allmessages(20)
   character*80 lines(100)
-  character*512 pchk_file,gen_file
   complex cbig(n)
   complex cdat(NPTS)                    !Analytic signal
   complex cdat2(NPTS)
@@ -48,10 +47,6 @@ subroutine detectmsk144(cbig,n,pchk_file,lines,nmessages,nutc,ntol,t00)
   data s8r/1,0,1,1,0,0,0,1/
   save df,first,cb,fs,pi,twopi,dt,s8,rcw,pp,nmatchedfilter
 
-  i=index(pchk_file,".pchk")
-  gen_file=pchk_file(1:i-1)//".gen"
-!  call init_ldpc(trim(pchk_file)//char(0),trim(gen_file)//char(0))
-
   if(first) then
      nmatchedfilter=1
 ! define half-sine pulse and raised-cosine edge window
@@ -382,11 +377,9 @@ subroutine detectmsk144(cbig,n,pchk_file,lines,nmessages,nutc,ntol,t00)
   
               max_iterations=10
               max_dither=1
-              call timer('ldpcdecod',0)
+              call timer('bpdec144 ',0)
-!              call ldpc_decode(lratio, decoded, &
-!                           max_iterations, niterations, max_dither, ndither)
               call bpdecode144(llr,max_iterations,decoded,niterations)
-              call timer('ldpcdecod',1)
+              call timer('bpdec144 ',1)
 
               if( niterations .ge. 0.0 ) then
                 call extractmessage144(decoded,msgreceived,nhashflag)

lib/detectmsk40.f90

@@ -1,4 +1,4 @@
-subroutine detectmsk40(cbig,n,pchk_file,mycall,hiscall,lines,nmessages,   &
+subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,   &
      nutc,ntol,t00)
 
   use timer_module, only: timer
@@ -7,8 +7,6 @@ subroutine detectmsk40(cbig,n,pchk_file,mycall,hiscall,lines,nmessages,   &
   character*6 mycall,hiscall,mycall0,hiscall0
   character*22 hashmsg,msgreceived
   character*80 lines(100)
-  character*512 pchk_file
-  character*512 pchk_file40,gen_file40
   complex cbig(n)
   complex cdat(NPTS)                    !Analytic signal
   complex cdat2(NPTS)
@@ -108,13 +106,6 @@ subroutine detectmsk40(cbig,n,pchk_file,mycall,hiscall,lines,nmessages,   &
      hiscall0=hiscall
   endif
 
-! Temporarily hardwire filenames and init on every call
-  i=index(pchk_file,"128-80")
-  pchk_file40=pchk_file(1:i-1)//"32-16"//pchk_file(i+6:)
-  i=index(pchk_file40,".pchk")
-  gen_file40=pchk_file40(1:i-1)//".gen"
-!  call init_ldpc(trim(pchk_file40)//char(0),trim(gen_file40)//char(0))
- 
 ! Fill the detmet, detferr arrays
   nstepsize=60  ! 5ms steps
   nstep=(n-NPTS)/nstepsize  
@@ -384,7 +375,6 @@ subroutine detectmsk40(cbig,n,pchk_file,mycall,hiscall,lines,nmessages,   &
 
               max_iterations=5
               max_dither=1
-!              call ldpc_decode(lratio,decoded,max_iterations,niterations,max_dither,ndither)
               call bpdecode40(llr,max_iterations, decoded, niterations)
               ncalls=ncalls+1
                

lib/encode_msk144.f90

@@ -8,7 +8,6 @@ subroutine encode_msk144(message,codeword)
 ! matrix stored in Radford Neal's "pchk" format.
 !
 character*20 g(48)
-character*1 tmpstr
 integer*1 codeword(128)
 integer*1 colorder(128)
 integer*1 gen144(48,80)

lib/fast_decode.f90

@@ -1,4 +1,4 @@
-subroutine fast_decode(id2,narg,ntrperiod,bShMsgs,line,pchk_file,     &
+subroutine fast_decode(id2,narg,ntrperiod,bShMsgs,line,     &
      mycall_12,hiscall_12)
 
   parameter (NMAX=30*12000)
@@ -13,7 +13,6 @@ subroutine fast_decode(id2,narg,ntrperiod,bShMsgs,line,pchk_file,     &
   logical pick,first
   character*6 cfile6
   character*80 line(100)
-  character*512 pchk_file
   character*12 mycall_12,hiscall_12
   character*6 mycall,hiscall
   data first/.true./
@@ -63,10 +62,10 @@ subroutine fast_decode(id2,narg,ntrperiod,bShMsgs,line,pchk_file,     &
 !     print*,ia,ib,nz,ndat0,t0,t1
      if(npick.gt.1) go to 900        !### DISABLE PICK FROM LOWER PANEL###
      if(newdat.eq.1 .or. npick.le.1) then
-        call msk144_decode(id2(ia),nz,nutc,0,pchk_file,mycall,hiscall,   &
+        call msk144_decode(id2(ia),nz,nutc,0,mycall,hiscall,   &
              bShMsgs,ntol,t0,line)
      else
-        call msk144_decode(id2b(ia),nz,nutc,0,pchk_file,mycall,hiscall,   &
+        call msk144_decode(id2b(ia),nz,nutc,0,mycall,hiscall,   &
              bShMsgs,ntol,t0,line)
      endif
      go to 900

lib/ldpcsim144.f90

@@ -6,7 +6,6 @@ use hashing
 use packjt
 character*22 msg,msgsent,msgreceived
 character*80 prefix
-character*85 pchk_file,gen_file
 character*8 arg
 integer*1, allocatable ::  codeword(:), decoded(:), message(:)
 integer*1, target:: i1Msg8BitBytes(10)
@@ -20,41 +19,31 @@ real, allocatable :: yy(:), llr(:)
 equivalence(ihash,i1hash)
 
 nargs=iargc()
-if(nargs.ne.7) then
+if(nargs.ne.4) then
-   print*,'Usage: ldpcsim  <pchk file prefix      >  N   K  niter ndither #trials  s '
+   print*,'Usage: ldpcsim  niter ndither #trials  s '
-   print*,'eg:    ldpcsim  "/pathto/peg-32-16-reg3"  32  16  10     1     1000    0.75'
+   print*,'eg:    ldpcsim    10     1     1000    0.75'
    return
 endif
-call getarg(1,prefix)
+call getarg(1,arg)
-call getarg(2,arg)
-read(arg,*) N 
-call getarg(3,arg)
-read(arg,*) K 
-call getarg(4,arg)
 read(arg,*) max_iterations 
-call getarg(5,arg)
+call getarg(2,arg)
 read(arg,*) max_dither 
-call getarg(6,arg)
+call getarg(3,arg)
 read(arg,*) ntrials 
-call getarg(7,arg)
+call getarg(4,arg)
 read(arg,*) s
 
-pchk_file=trim(prefix)//".pchk"
-gen_file=trim(prefix)//".gen"
-
 !rate=real(K)/real(N)
 ! don't count hash bits as data bits
 rate=72.0/real(N)
 
 write(*,*) "rate: ",rate
 
-write(*,*) "pchk file: ",pchk_file
 write(*,*) "niter= ",max_iterations," ndither= ",max_dither," s= ",s
 
 allocate ( codeword(N), decoded(K), message(K) )
 allocate ( lratio(N), rxdata(N), yy(N), llr(N) )
 
-call init_ldpc(trim(pchk_file)//char(0),trim(gen_file)//char(0))
 msg="K9AN K1JT EN50"
   call packmsg(msg,i4Msg6BitWords,itype)  !Pack into 12 6-bit bytes
   call unpackmsg(i4Msg6BitWords,msgsent)  !Unpack to get msgsent

lib/ldpcsim40.f90

@@ -5,8 +5,6 @@ use hashing
 use packjt
 
 character*22 msg,msgsent,msgreceived
-character*80 prefix
-character*85 pchk_file,gen_file
 character*8 arg
 integer*1, allocatable ::  codeword(:), decoded(:), message(:)
 real*8, allocatable ::  lratio(:), rxdata(:)
@@ -15,38 +13,28 @@ integer ihash
 integer*1 hardbits(32)
 
 nargs=iargc()
-if(nargs.ne.7) then
+if(nargs.ne.4) then
-   print*,'Usage: ldpcsim  <pchk file prefix      >  N   K  niter ndither #trials  s '
+   print*,'Usage: ldpcsim  niter ndither #trials  s '
-   print*,'eg:    ldpcsim  "/pathto/peg-32-16-reg3"  32  16  10     1     1000    0.75'
+   print*,'eg:    ldpcsim   10     1     1000    0.75'
    return
 endif
-call getarg(1,prefix)
+call getarg(1,arg)
-call getarg(2,arg)
-read(arg,*) N 
-call getarg(3,arg)
-read(arg,*) K 
-call getarg(4,arg)
 read(arg,*) max_iterations 
-call getarg(5,arg)
+call getarg(2,arg)
 read(arg,*) max_dither 
-call getarg(6,arg)
+call getarg(3,arg)
 read(arg,*) ntrials 
-call getarg(7,arg)
+call getarg(4,arg)
 read(arg,*) s
 
-pchk_file=trim(prefix)//".pchk"
-gen_file=trim(prefix)//".gen"
-
 rate=real(K)/real(N)
 ! don't count hash bits as data bits
 !rate=5.0/real(N)
 write(*,*) "rate: ",rate
-write(*,*) "pchk file: ",pchk_file
 write(*,*) "niter= ",max_iterations," ndither= ",max_dither," s= ",s
 
 allocate ( codeword(N), decoded(K), message(K) )
 allocate ( lratio(N), rxdata(N), llr(N) )
-call init_ldpc(trim(pchk_file)//char(0),trim(gen_file)//char(0))
 
 msg="K1JT K9AN RRR         "
 irpt=14
@@ -59,8 +47,6 @@ do i=1,16
   message(i)=iand(1,ishft(ig,1-i))
 enddo
 write(*,'(16i1)') message
-!call ldpc_encode(message,codeword)
-!write(*,'(32i1)') codeword 
 call encode_msk40(message,codeword)
 write(*,'(32i1)') codeword
 call init_random_seed()
@@ -95,7 +81,6 @@ do idb = -6, 14
     llr=2.0*rxdata/(ss*ss)
     lratio=exp(llr)
 
-!    call ldpc_decode(lratio, decoded, max_iterations, niterations, max_dither, ndither)
     call bpdecode40(llr, max_iterations, decoded, niterations)
 ! If the decoder finds a valid codeword, niterations will be .ge. 0.
     if( niterations .ge. 0 ) then

lib/msk144_decode.f90

@@ -1,4 +1,4 @@
-subroutine msk144_decode(id2,npts,nutc,nprint,pchk_file,mycall,hiscall,   &
+subroutine msk144_decode(id2,npts,nutc,nprint,mycall,hiscall,   &
      bShMsgs,ntol,t0,line)
 
 ! Calls the experimental decoder for MSK 72ms/16ms messages
@@ -10,7 +10,6 @@ subroutine msk144_decode(id2,npts,nutc,nprint,pchk_file,mycall,hiscall,   &
   real d(0:NMAX)                       !Raw r*4 data
   complex c(NFFTMAX)                   !Complex (analytic) data
   character*80 line(100)               !Decodes passed back to caller
-  character*512 pchk_file
   character*6 mycall,hiscall
   logical*1 bShMsgs
 
@@ -37,7 +36,7 @@ subroutine msk144_decode(id2,npts,nutc,nprint,pchk_file,mycall,hiscall,   &
   call analytic(d,npts,nfft,c)         !Convert to analytic signal and filter
   call timer('analytic',1)
   call timer('detec144',0)
-  call detectmsk144(c,npts,pchk_file,line,nline,nutc,ntol,t0)
+  call detectmsk144(c,npts,line,nline,nutc,ntol,t0)
   call timer('detec144',1)
   if( nprint .ne. 0 ) then
     do i=1,nline
@@ -48,7 +47,7 @@ subroutine msk144_decode(id2,npts,nutc,nprint,pchk_file,mycall,hiscall,   &
 
   if(nline.eq.0 .and. bShMsgs) then
     call timer('detect40',0)
-    call detectmsk40(c,npts,pchk_file,mycall,hiscall,line,nline,nutc,ntol,t0)
+    call detectmsk40(c,npts,mycall,hiscall,line,nline,nutc,ntol,t0)
     call timer('detect40',1)
     if( nprint .ne. 0 ) then
       do i=1,nline

lib/msk144sim.f90

@@ -5,18 +5,12 @@ program msk144sim
   real pings(0:NMAX-1)
   real waveform(0:NMAX-1)
   character arg*8,msg*22,msgsent*22,fname*40
-  character*512 encode_exe_file
-  character*512 pchk_file
-  character*512 ldpc_msg_file
   real wave(0:NMAX-1)              !Simulated received waveform
   real*8 twopi,freq,phi,dphi0,dphi1,dphi
   type(hdr) h                          !Header for .wav file
   integer*2 iwave(0:NMAX-1)
   integer itone(144)                   !Message bits
 
-  pchk_file='./peg-128-80-reg3.pchk'
-  ldpc_msg_file='./ldpc_msg'
-
   nargs=iargc()
   if(nargs.ne.5) then
      print*,'Usage:    msk144sim        message       freq width snr nfiles'

main.cpp

@@ -42,7 +42,6 @@
 extern "C" {
   // Fortran procedures we need
   void four2a_(_Complex float *, int * nfft, int * ndim, int * isign, int * iform, int len);
-  void fini_ldpc_ ();
 }
 
 namespace
@@ -348,7 +347,6 @@ int main(int argc, char *argv[])
       }
       fftwf_forget_wisdom ();
       fftwf_cleanup ();
-      fini_ldpc_ ();            // free LDPC decoder resources
 
       temp_dir.removeRecursively (); // clean up temp files
       return result;

mainwindow.cpp

@@ -109,7 +109,7 @@ extern "C" {
                 float* width);
 
   void fast_decode_(short id2[], int narg[], int* ntrperiod, bool* bShMsgs,
-                    char msg[], char pchkFile[], char mycall[], char hiscall[],
+                    char msg[], char mycall[], char hiscall[],
                     int len1, int len2, int len3, int len4);
   void hash_calls_(char calls[], int* ih9, int len);
   void degrade_snr_(short d2[], int* n, float* db, float* bandwidth);
@@ -831,27 +831,6 @@ MainWindow::MainWindow(QDir const& temp_directory, bool multiple,
     int ntr[]={5,10,15,30};
     m_TRperiod=ntr[m_TRindex-11];
   }
-  QString pchkFile = m_config.data_dir().absoluteFilePath("peg-128-80-reg3.pchk");
-  QByteArray ba = pchkFile.toLocal8Bit();
-  for(int i=0; i<512; i++) {
-    m_pchkFile[i]=32;
-    if(i<pchkFile.length()) m_pchkFile[i]=ba[i];
-  }
-
-  QString ldpcMsgFile = m_config.temp_dir().absoluteFilePath("ldpc_msg");
-  ba = ldpcMsgFile.toLocal8Bit();
-  for(int i=0; i<512; i++) {
-    m_ldpcMsgFile[i]=32;
-    if(i<ldpcMsgFile.length()) m_ldpcMsgFile[i]=ba[i];
-  }
-
-  QString encodeExeFile = QDir::toNativeSeparators (m_appDir) +
-      QDir::separator () + "encode";
-  ba = encodeExeFile.toLocal8Bit();
-  for(int i=0; i<512; i++) {
-    m_encodeExeFile[i]=32;
-    if(i<encodeExeFile.length()) m_encodeExeFile[i]=ba[i];
-  }
   statusChanged();
 
   m_wideGraph->setMode(m_mode);
@@ -2235,7 +2214,7 @@ void MainWindow::decode()                                       //decode()
     narg[14]=m_config.aggressive();
     memcpy(d2b,dec_data.d2,2*360000);
     watcher3.setFuture (QtConcurrent::run (std::bind (fast_decode_,&d2b[0],
-        &narg[0],&m_TRperiod,&m_bShMsgs,&m_msg[0][0],&m_pchkFile[0],
+        &narg[0],&m_TRperiod,&m_bShMsgs,&m_msg[0][0],
         dec_data.params.mycall,dec_data.params.hiscall,80,512,12,12)));
   } else {
     memcpy(to, from, qMin(mem_jt9->size(), size));

mainwindow.h

@@ -429,9 +429,6 @@ private:
   bool		m_first_error;
 
   char    m_msg[100][80];
-  char    m_pchkFile[512];
-  char    m_ldpcMsgFile[512];
-  char    m_encodeExeFile[512];
 
   // labels in status bar
   QLabel tx_status_label;