mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-08 18:16:02 -05:00
7369062c4a
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@2635 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
34 lines
800 B
Fortran
34 lines
800 B
Fortran
subroutine encode232(dat,nsym,symbol)
|
|
|
|
! Convolutional encoder for a K=32, r=1/2 code.
|
|
|
|
integer*1 dat(13) !User data, packed 8 bits per byte
|
|
integer*1 symbol(500) !Channel symbols, one bit per byte
|
|
integer*1 i1
|
|
include 'conv232.f90'
|
|
|
|
nstate=0
|
|
k=0
|
|
do j=1,nsym
|
|
do i=7,0,-1
|
|
i1=dat(j)
|
|
i4=i1
|
|
if (i4.lt.0) i4=i4+256
|
|
nstate=ior(ishft(nstate,1),iand(ishft(i4,-i),1))
|
|
n=iand(nstate,npoly1)
|
|
n=ieor(n,ishft(n,-16))
|
|
k=k+1
|
|
symbol(k)=partab(iand(ieor(n,ishft(n,-8)),255))
|
|
n=iand(nstate,npoly2)
|
|
n=ieor(n,ishft(n,-16))
|
|
k=k+1
|
|
symbol(k)=partab(iand(ieor(n,ishft(n,-8)),255))
|
|
if(k.ge.nsym) go to 100
|
|
enddo
|
|
enddo
|
|
|
|
100 continue
|
|
|
|
return
|
|
end subroutine encode232
|