mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-10-31 23:57:10 -04:00
808259b7bf
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7051 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
112 lines
3.1 KiB
Fortran
112 lines
3.1 KiB
Fortran
subroutine encode_msk144(message,codeword)
|
|
! Encode an 80-bit message and return a 128-bit codeword.
|
|
! The generator matrix has dimensions (48,80).
|
|
! The code is a (128,80) regular ldpc code with column weight 3.
|
|
! The code was generated using the PEG algorithm.
|
|
! After creating the codeword, the columns are re-ordered according to
|
|
! "colorder" to make the codeword compatible with the parity-check
|
|
! matrix stored in Radford Neal's "pchk" format.
|
|
!
|
|
character*20 g(48)
|
|
integer*1 codeword(128)
|
|
integer*1 colorder(128)
|
|
integer*1 gen144(48,80)
|
|
integer*1 itmp(128)
|
|
integer*1 message(80)
|
|
integer*1 pchecks(48)
|
|
logical first
|
|
data first/.true./
|
|
data g/ & !parity-check generator matrix for (128,80) code
|
|
"24084000800020008000", &
|
|
"b39678f7ccdb1baf5f4c", &
|
|
"10001000400408012000", &
|
|
"08104000100002010800", &
|
|
"dc9c18f61ea0e4b7f05c", &
|
|
"42c040160909ca002c00", &
|
|
"cc50b52b9a80db0d7f9e", &
|
|
"dde5ace80780bae74740", &
|
|
"00800080020000890080", &
|
|
"01020040010400400040", &
|
|
"20008010020000100030", &
|
|
"80400008004000040050", &
|
|
"a4b397810915126f5604", &
|
|
"04040100001040200008", &
|
|
"00800006000888000800", &
|
|
"00010c00000104040001", &
|
|
"cc7cd7d953cdc204eba0", &
|
|
"0094abe7dd146beb16ce", &
|
|
"5af2aec8c7b051c7544a", &
|
|
"14040508801840200088", &
|
|
"7392f5e720f8f5a62c1e", &
|
|
"503cc2a06bff4e684ec9", &
|
|
"5a2efd46f1efbb513b80", &
|
|
"ac06e9513fd411f1de03", &
|
|
"16a31be3dd3082ca2bd6", &
|
|
"28542e0daf62fe1d9332", &
|
|
"00210c002001540c0401", &
|
|
"0ed90d56f84298706a98", &
|
|
"939670f7ecdf9baf4f4c", &
|
|
"cfe41dec47a433e66240", &
|
|
"16d2179c2d5888222630", &
|
|
"408000160108ca002800", &
|
|
"808000830a00018900a0", &
|
|
"9ae2ed8ef3afbf8c3a52", &
|
|
"5aaafd86f3efbfc83b02", &
|
|
"f39658f68cdb0baf1f4c", &
|
|
"9414bb6495106261366a", &
|
|
"71ba18670c08411bf682", &
|
|
"7298f1a7217cf5c62e5e", &
|
|
"86d7a4864396a981369b", &
|
|
"a8042c01ae22fe191362", &
|
|
"9235ae108b2d60d0e306", &
|
|
"dfe5ade807a03be74640", &
|
|
"d2451588e6e27ccd9bc4", &
|
|
"12b51ae39d20e2ea3bde", &
|
|
"a49387810d95136fd604", &
|
|
"467e7578e51d5b3b8a0e", &
|
|
"f6ad1ac7cc3aaa3fe580"/
|
|
|
|
data colorder/0,1,2,3,4,5,6,7,8,9, &
|
|
10,11,12,13,14,15,24,26,29,30, &
|
|
32,43,44,47,60,77,79,97,101,111, &
|
|
96,38,64,53,93,34,59,94,74,90, &
|
|
108,123,85,57,70,25,69,62,48,49, &
|
|
50,51,52,33,54,55,56,21,58,36, &
|
|
16,61,23,63,20,65,66,67,68,46, &
|
|
22,71,72,73,31,75,76,45,78,17, &
|
|
80,81,82,83,84,42,86,87,88,89, &
|
|
39,91,92,35,37,95,19,27,98,99, &
|
|
100,28,102,103,104,105,106,107,40,109, &
|
|
110,18,112,113,114,115,116,117,118,119, &
|
|
120,121,122,41,124,125,126,127/
|
|
|
|
save first,gen144
|
|
|
|
if( first ) then ! fill the generator matrix
|
|
gen144=0
|
|
do i=1,48
|
|
do j=1,5
|
|
read(g(i)( (j-1)*4+1:(j-1)*4+4 ),"(Z4)") istr
|
|
do jj=1,16
|
|
icol=(j-1)*16+jj
|
|
if( btest(istr,16-jj) ) gen144(i,icol)=1
|
|
enddo
|
|
enddo
|
|
enddo
|
|
first=.false.
|
|
endif
|
|
|
|
do i=1,48
|
|
nsum=0
|
|
do j=1,80
|
|
nsum=nsum+message(j)*gen144(i,j)
|
|
enddo
|
|
pchecks(i)=mod(nsum,2)
|
|
enddo
|
|
itmp(1:48)=pchecks
|
|
itmp(49:128)=message(1:80)
|
|
codeword(colorder+1)=itmp(1:128)
|
|
|
|
return
|
|
end subroutine encode_msk144
|