WSJT-X/libm65/genjt9.f90
Joe Taylor 6dcf5787c3 More work on jt9sim.
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@2604 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
2012-09-28 19:42:00 +00:00

70 lines
2.3 KiB
Fortran

subroutine genjt9(message,minutes,msgsent,d6)
! Encodes a "JT9-minutes" message and returns array d6(85) of tone
! values in the range 0-8.
character*22 message !Message to be generated
character*22 msgsent !Message as it will be received
integer*4 d0(13) !72-bit message as 6-bit words
integer*1 d1(13) !72 bits and zero tail as 8-bit bytes
integer*1 d2(206) !Encoded information-carrying bits
integer*1 d3(206) !Bits from d2, after interleaving
integer*4 d4(69) !Symbols from d3, values 0-7
integer*4 d5(69) !Gray-coded symbols, values 0-7
integer*4 d6(85) !Channel symbols including sync, values 0-8
integer*4 t0(13) !72-bit message as 6-bit words
integer*1 t1(13) !72 bits and zero tail as 8-bit bytes
integer*1 t2(206) !Encoded information-carrying bits
integer*1 t3(206) !Bits from d2, after interleaving
integer*4 t4(69) !Symbols from d3, values 0-7
integer*4 t5(69) !Gray-coded symbols, values 0-7
integer*4 t6(85) !Channel symbols including sync, values 0-8
integer isync(85)
data isync/ &
1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1,0,0,0,0, &
1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,1,0, &
0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0, &
0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0, &
1,0,0,0,1/
data twopi/6.283185307179586476d0/
save
call packmsg(message,d0) !Pack message into 12 6-bit bytes
call unpackmsg(d0,msgsent)
call entail(d0,d1)
nsym2=206
call encode232(d1,nsym2,d2) !Convolutional code, K=32, r=1/2
call interleave9(d2,1,d3)
call packbits(d3,nsym2,3,d4)
call graycode(d4,69,1,d5)
! Insert sync symbols (ntone=0) and add 1 to the data-tone numbers.
j=0
do i=1,85
if(isync(i).eq.1) then
d6(i)=0
else
j=j+1
d6(i)=d5(j)+1
endif
enddo
! t6=d6
! j=0
! do i=1,85
! if(isync(i).eq.1) cycle
! j=j+1
! t5(j)=t6(i)-1
! enddo
! call graycode(t5,69,-1,t4)
! call unpackbits(t4,nsym2,3,t3)
! call interleave9(t3,-1,t2)
! print*,'A',d2-t2
return
end subroutine genjt9