Progress toward a working ldpc128_90 simulator. Compiles, but does not yet work.

CMakeLists.txt

@@ -313,12 +313,14 @@ set (wsjtx_CXXSRCS
 set (wsjt_CXXSRCS
   lib/crc10.cpp
   lib/crc12.cpp
+  lib/crc13.cpp
   lib/crc14.cpp
   )
 # deal with a GCC v6 UB error message
 set_source_files_properties (
   lib/crc10.cpp
   lib/crc12.cpp
+  lib/crc13.cpp
   lib/crc14.cpp
   PROPERTIES COMPILE_FLAGS -fpermissive)
 
@@ -371,6 +373,7 @@ set (wsjt_FSRCS
   lib/ft8/baseline.f90
   lib/bpdecode40.f90
   lib/bpdecode144.f90
+  lib/bpdecode128_90.f90
   lib/fsk4hf/bpdecode120.f90
   lib/fsk4hf/bpdecode168.f90
   lib/ft8/bpdecode174.f90
@@ -409,6 +412,7 @@ set (wsjt_FSRCS
   lib/encode4.f90
   lib/encode_msk40.f90
   lib/encode_msk144.f90
+  lib/encode128_90.f90
   lib/fsk4hf/encode120.f90
   lib/fsk4hf/encode168.f90
   lib/ft8/encode174.f90
@@ -420,6 +424,7 @@ set (wsjt_FSRCS
   lib/extract.f90
   lib/extract4.f90
   lib/extractmessage144.f90
+  lib/extractmessage128_90.f90
   lib/fsk4hf/extractmessage168.f90
   lib/ft8/extractmessage174.f90
   lib/ft8/extractmessage174_91.f90
@@ -502,6 +507,7 @@ set (wsjt_FSRCS
   lib/jt9fano.f90
   lib/jtmsg.f90
   lib/ldpcsim144.f90
+  lib/ldpcsim128_90.f90
   lib/fsk4hf/ldpcsim120.f90
   lib/fsk4hf/ldpcsim168.f90
   lib/ft8/ldpcsim174.f90
@@ -1248,6 +1254,9 @@ target_link_libraries (ldpcsim174_91 wsjt_fort wsjt_cxx)
 add_executable (ldpcsim144 lib/ldpcsim144.f90 wsjtx.rc)
 target_link_libraries (ldpcsim144 wsjt_fort wsjt_cxx)
 
+add_executable (ldpcsim128_90 lib/ldpcsim128_90.f90 wsjtx.rc)
+target_link_libraries (ldpcsim128_90 wsjt_fort wsjt_cxx)
+
 add_executable (ldpcsim168 lib/fsk4hf/ldpcsim168.f90 wsjtx.rc)
 target_link_libraries (ldpcsim168 wsjt_fort wsjt_cxx)
 

lib/bpdecode128_90.f90

@@ -94,7 +94,7 @@ do iter=0,maxiterations
 
 ! send messages from check nodes to variable nodes
   do i=1,M
-    tanhtoc(1:7,i)=tanh(-toc(1:7,i)/2)
+    tanhtoc(1:11,i)=tanh(-toc(1:11,i)/2)
   enddo
 
   do j=1,N

lib/crc.f90

@@ -18,6 +18,22 @@ module crc
       integer (c_int), value :: length
     end function crc14_check
 
+    function crc13 (data, length) bind (C, name="crc13")
+      use, intrinsic :: iso_c_binding, only: c_short, c_ptr, c_int
+      implicit none
+      integer (c_short) :: crc13
+      type (c_ptr), value :: data
+      integer (c_int), value :: length
+    end function crc13
+ 
+    function crc13_check (data, length) bind (C, name="crc14_check")
+      use, intrinsic :: iso_c_binding, only: c_bool, c_ptr, c_int
+      implicit none
+      logical (c_bool) :: crc13_check
+      type (c_ptr), value :: data
+      integer (c_int), value :: length
+    end function crc13_check
+
     function crc12 (data, length) bind (C, name="crc12")
       use, intrinsic :: iso_c_binding, only: c_short, c_ptr, c_int
       implicit none

lib/extractmessage128_90.f90

@@ -7,20 +7,25 @@ subroutine extractmessage128_90(decoded,msgreceived,ncrcflag)
   character*90 cbits
   integer*1 decoded(90)
   integer*1, target::  i1Dec8BitBytes(12)
+  integer*2 icrc13
   integer*4 i4Dec6BitWords(12)
 
 ! Write decoded bits into cbits: 77-bit message plus 13-bit CRC
   write(cbits,1000) decoded
 1000 format(90i1)
+write(*,*) cbits
   read(cbits,1001) i1Dec8BitBytes
 1001 format(12b8)
   read(cbits,1002) ncrc13                         !Received CRC12
 1002 format(77x,b13)
 
   i1Dec8BitBytes(10)=iand(i1Dec8BitBytes(10),128+64+32+16+8)
+write(*,*) i1Dec8BitBytes
   i1Dec8BitBytes(11:12)=0
   icrc13=crc13(c_loc(i1Dec8BitBytes),12)          !CRC13 computed from 77 msg bits
 
+write(*,'(b13,3x,b13)') ncrc13,icrc13
+
   if(ncrc13.eq.icrc13 .or. sum(decoded(57:87)).eq.0) then  !### Kludge ###  ???
 ! CRC13 checks out --- unpack 72-bit message
     read(cbits,'(12b6)') i4Dec6BitWords 

lib/ldpcsim128_90.f90

@@ -11,11 +11,14 @@ character*96 tmpchar
 character*8 arg
 integer*1, allocatable ::  codeword(:), decoded(:), message(:)
 integer*1, target:: i1Msg8BitBytes(12)
+integer*1 apmask(N),cw(N)
 integer*1 i1hash(4)
-integer*1 msgbits(80)
+integer*1 msgbits(90)
+integer*2 checksum
 integer*4 i4Msg6BitWords(13)
 integer ihash
-integer nerrtot(N),nerrdec(N),nmpcbad(K)
+integer nerrtot(0:N),nerrdec(0:N),nmpcbad(0:K)
+logical checksumok
 real*8, allocatable ::  lratio(:), rxdata(:), rxavgd(:)
 real, allocatable :: yy(:), llr(:)
 equivalence(ihash,i1hash)
@@ -41,7 +44,6 @@ read(arg,*) ntrials
 call getarg(4,arg)
 read(arg,*) s
 
-! don't count hash bits as data bits
 rate=real(K)/real(N)
 
 write(*,*) "rate: ",rate
@@ -51,30 +53,30 @@ write(*,*) "niter= ",max_iterations," navg= ",navg," s= ",s
 allocate ( codeword(N), decoded(K), message(K) )
 allocate ( lratio(N), rxdata(N), rxavgd(N), yy(N), llr(N) )
 
-msg="K9AN K1JT EN50"
+!msg="K9AN K1JT EN50"
+msg="G4WJS K1JT FN20"
   call packmsg(msg,i4Msg6BitWords,itype,.false.) !Pack into 12 6-bit bytes
   call unpackmsg(i4Msg6BitWords,msgsent,.false.,'      ') !Unpack to get msgsent
   write(*,*) "message sent ",msgsent
 
   tmpchar=' '
-  write(tmpchar,'(12b6.6)') i4Msg6BitWords
+  write(tmpchar,'(12b6)') i4Msg6BitWords(1:12)
   tmpchar(73:77)="00000"   !i5bit
-  write(*,*) tmpchar
 
   read(tmpchar,'(10b8)') i1Msg8BitBytes(1:10)
   write(*,*) i1Msg8BitBytes
 
   i1Msg8BitBytes(10:12)=0 
-  checksum = crc13 (c_loc (i1Msg8ZBitZBytes), 12)
+  checksum = crc13 (c_loc (i1Msg8BitBytes), 12)
-  i1Msg8BitBytes(11)=checksum/256
+  write(*,'(i6,3x,b13)') checksum,checksum
-  i1Msg8BitBytes(12)=iand (checksum,255)
-  checksumok = crc13_check(c_loc (i1Msg8ZBitBytes), 12)
-  if( checksumok ) write(*,*) 'Good checksum'
 
-  write(tmpchar,'(12b8.8)') i1Msg8BitBytes(1:9)
+  write(tmpchar(78:90),'(b13)') checksum
-  read(tmpchar,'(77b)') msgbits(1:77)
+  read(tmpchar,'(90i1)') msgbits(1:90)
-  read(tmpchar(84:96),'(6b)') msgbits(78:90)
+
-  call encode_128_90(msgbits,codeword)
+  write(*,*) 'msgbits'
+  write(*,'(28i1,1x,28i1,1x,16i1,1x,5i1,1x,13i1)') msgbits
+
+  call encode128_90(msgbits,codeword)
 
   call init_random_seed()
 
@@ -103,13 +105,10 @@ do idb = -6, 14
     enddo
     nerrtot(nerr)=nerrtot(nerr)+1
 
-! 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
@@ -122,13 +121,15 @@ do idb = -6, 14
     lratio=exp(llr)
     yy=rxdata
 
+    apmask=0
 ! max_iterations is max number of belief propagation iterations
     call bpdecode128_90(llr, apmask, max_iterations, decoded, cw, nharderrors, niterations)
 
 ! If the decoder finds a valid codeword, nharderrors will be .ge. 0.
     if( nharderrors .ge. 0 ) then
-      call extractmessage1128_90(decoded,msgreceived,ncrcflag)
+      call extractmessage128_90(decoded,msgreceived,ncrcflag)
-      if( nncrcflag .ne. 1 ) then
+write(*,*) 'crc check flag ',ncrcflag
+      if( ncrcflag .ne. 1 ) then
         nbadcrc=nbadcrc+1
       endif
 
@@ -140,17 +141,17 @@ do idb = -6, 14
           nerrmpc=nerrmpc+1
         endif
       enddo
-      if(nerrmpc.ge.1) nmpcbad(nerrmpc)=nmpcbad(nerrmpc)+1
+      nmpcbad(nerrmpc)=nmpcbad(nerrmpc)+1
       if( ncrcflag .eq. 1) then
         ngood=ngood+1
-        if(nerr.ge.1) nerrdec(nerr)=nerrdec(nerr)+1
+        nerrdec(nerr)=nerrdec(nerr)+1
       else if(nueflag .eq. 1 ) then
         nue=nue+1;
       endif
     endif
   enddo
   snr2500=db-3.5
-  pberr=real(nberr)/real(ntrials*N)
+  pberr=real(nerr)/real(ntrials*N)
   write(*,"(f4.1,4x,f5.1,1x,i8,1x,i8,1x,i8,8x,f5.2,8x,e10.3)") db,snr2500,ngood,nue,nbadcrc,ss,pberr
   
 enddo