mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-29 15:48:38 -05:00
45 lines
959 B
Fortran
45 lines
959 B
Fortran
|
subroutine encode240_74(message,codeword)
|
||
|
|
use, intrinsic :: iso_c_binding
|
||
|
|
use iso_c_binding, only: c_loc,c_size_t
|
||
|
|
use crc
|
||
|
|
|
||
|
|
integer, parameter:: N=240, K=74, M=N-K
|
||
|
|
integer*1 codeword(N)
|
||
|
|
integer*1 gen(M,K)
|
||
|
|
integer*1 message(K)
|
||
|
|
integer*1 pchecks(M)
|
||
|
|
include "ldpc_240_74_generator.f90"
|
||
|
|
logical first
|
||
|
|
data first/.true./
|
||
|
|
save first,gen
|
||
|
|
|
||
|
|
if( first ) then ! fill the generator matrix
|
||
|
|
gen=0
|
||
|
|
do i=1,M
|
||
|
|
do j=1,19
|
||
|
|
read(g(i)(j:j),"(Z1)") istr
|
||
|
|
ibmax=4
|
||
|
|
if(j.eq.19) ibmax=2
|
||
|
|
do jj=1, ibmax
|
||
|
|
icol=(j-1)*4+jj
|
||
|
|
if( btest(istr,4-jj) ) gen(i,icol)=1
|
||
|
|
enddo
|
||
|
|
enddo
|
||
|
|
enddo
|
||
|
|
first=.false.
|
||
|
|
endif
|
||
|
|
|
||
|
|
do i=1,M
|
||
|
|
nsum=0
|
||
|
|
do j=1,K
|
||
|
|
nsum=nsum+message(j)*gen(i,j)
|
||
|
|
enddo
|
||
|
|
pchecks(i)=mod(nsum,2)
|
||
|
|
enddo
|
||
|
|
|
||
|
|
codeword(1:K)=message
|
||
|
|
codeword(K+1:N)=pchecks
|
||
|
|
|
||
|
|
return
|
||
|
|
end subroutine encode240_74
|