From 13c9938607aef6978605e255b1914d176c8b7608 Mon Sep 17 00:00:00 2001
From: Joe Taylor <k1jt@arrl.org>
Date: Tue, 24 Nov 2015 19:49:04 +0000
Subject: [PATCH] Implement (still in very basic form) experience-based
 decoding for JT65.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6174 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
---
 CMakeLists.txt       |  1 +
 lib/exp_decode65.f90 | 95 ++++++++++++++++++++++++++++++++++++++++++++
 lib/extract.f90      | 27 ++++++++-----
 3 files changed, 112 insertions(+), 11 deletions(-)
 create mode 100644 lib/exp_decode65.f90

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 79355857e..12c6f8227 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -286,6 +286,7 @@ set (wsjt_FSRCS
   lib/encode4.f90
   lib/entail.f90
   lib/ephem.f90
+  lib/exp_decode65.f90
   lib/extract.f90
   lib/extract4.f90
   lib/fano232.f90
diff --git a/lib/exp_decode65.f90 b/lib/exp_decode65.f90
new file mode 100644
index 000000000..4ceeb109c
--- /dev/null
+++ b/lib/exp_decode65.f90
@@ -0,0 +1,95 @@
+subroutine exp_decode65(mrsym,mrprob,mr2sym,nhard,nsoft,nbest,correct)
+
+  use packjt
+  use prog_args
+  parameter (NMAX=10000)
+  integer*1 sym1(0:62,NMAX)
+  integer mrsym(0:62),mr2sym(0:62),mrprob(0:62)
+  integer dgen(12),sym(0:62),sym_rev(0:62)
+  integer test(0:62)  
+  integer correct(0:62)
+  character*6 mycall,hiscall(NMAX)
+  character*4 hisgrid(NMAX)
+  character callsign*12,grid*4
+  character*180 line
+  character ceme*3,msg*22
+  logical*1 eme(NMAX)
+  logical first
+  data first/.true./
+  save first,sym1,nused
+
+!###
+  mycall='VK7MO'                   !### TEMPORARY ###
+  if(first) then
+     neme=1
+
+     open(23,file=trim(data_dir)//'/CALL3.TXT',status='unknown')
+     icall=0
+     j=0
+     do i=1,NMAX
+        read(23,1002,end=10) line
+1002    format(a80)
+        if(line(1:4).eq.'ZZZZ') cycle
+        if(line(1:2).eq.'//') cycle
+        i1=index(line,',')
+        if(i1.lt.4) cycle
+        i2=index(line(i1+1:),',')
+        if(i2.lt.5) cycle
+        i2=i2+i1
+        i3=index(line(i2+1:),',')
+        if(i3.lt.1) i3=index(line(i2+1:),' ')
+        i3=i2+i3
+        callsign=line(1:i1-1)
+        grid=line(i1+1:i2-1)
+        ceme=line(i2+1:i3-1)
+        eme(i)=ceme.eq.'EME'
+        if(neme.eq.1 .and. (.not.eme(i))) cycle
+        j=j+1
+        hiscall(j)=callsign(1:6)               !### Fix for compound callsigns!
+        hisgrid(j)=grid
+     enddo
+10   ncalls=j
+     close(23)
+
+     j=0
+     do i=1,ncalls
+        if(neme.eq.1 .and. (.not.eme(i))) cycle
+        j=j+1
+        msg=mycall//' '//hiscall(i)//' '//hisgrid(i)
+        call fmtmsg(msg,iz)
+        call packmsg(msg,dgen,itype)            !Pack message into 72 bits
+        call rs_encode(dgen,sym_rev)            !RS encode
+        sym(0:62)=sym_rev(62:0:-1)
+        sym1(0:62,j)=sym
+     enddo
+     nused=j
+     first=.false.
+  endif
+!###
+
+  nbest=999999
+  do j=1,nused
+     test=sym1(0:62,j)
+     nh=0
+     ns=0
+     do i=0,62
+        k=62-i
+        if(mrsym(k).ne.test(i)) then
+           nh=nh+1
+           if(mr2sym(k).ne.test(i)) ns=ns+mrprob(k)
+        endif
+     enddo
+     ns=63*ns/sum(mrprob)
+
+     if(nh+ns.lt.nbest) then
+        nhard=nh
+        nsoft=ns
+        nbest=nhard+nsoft
+        ncandidates=0
+        ntry=0
+        correct=test
+     endif
+  enddo
+
+  return
+end subroutine exp_decode65
diff --git a/lib/extract.f90 b/lib/extract.f90
index a8654134c..0484030b6 100644
--- a/lib/extract.f90
+++ b/lib/extract.f90
@@ -61,10 +61,9 @@ subroutine extract(s3,nadd,nqd,ntrials,naggressive,ndepth,ncount,nhist,   &
   call graycode65(mr2sym,63,-1)      !Remove gray code and interleaving
   call interleave63(mr2sym,-1)       !from second-most-reliable symbols
   call interleave63(mr2prob,-1)
-
-  write(71) mrsym,mrprob,mr2sym,mr2prob
-  nverbose=0
   ntry=0
+
+  nverbose=0
   call timer('sfrsd   ',0)
   call sfrsd2(mrsym,mrprob,mr2sym,mr2prob,ntrials,nverbose,correct,   &
        param,indx,tt,ntry)
@@ -72,20 +71,27 @@ subroutine extract(s3,nadd,nqd,ntrials,naggressive,ndepth,ncount,nhist,   &
   ncandidates=param(0)
   nhard=param(1)
   nsoft=param(2)
-  nera=param(3)
-  ngmd=param(4)
-  ndone=ndone+1
-  do i=1,12
-     dat4(i)=correct(13-i)
-  enddo
 
+  if(nhard.lt.0 .and. ndepth.ge.5) then
+     call timer('exp_deco',0)
+     call exp_decode65(mrsym,mrprob,mr2sym,nhard,nsoft,nbest,correct)
+     if(nbest.gt.72+2*naggressive) then
+        nhard=-1
+     endif
+     call timer('exp_deco',1)
+  endif
+
+  ndone=ndone+1
   ncount=-1
   decoded='                      '
   ltext=.false.
   if(nhard.ge.0) then
     !turn the corrected symbol array into channel symbols for subtraction
     !pass it back to jt65a via common block "chansyms65"
-    do i=1,63
+     do i=1,12
+        dat4(i)=correct(13-i)
+     enddo
+     do i=1,63
        tmp(i)=correct(64-i)
      enddo
      correct(1:63)=tmp(1:63)
@@ -100,4 +106,3 @@ subroutine extract(s3,nadd,nqd,ntrials,naggressive,ndepth,ncount,nhist,   &
 
   return
 end subroutine extract
-