66 lines
2.3 KiB
Fortran
66 lines
2.3 KiB
Fortran
subroutine gen9(msg0,ichk,msgsent,i4tone,itype)
|
|
|
|
! Encodes a JT9 message and returns msgsent, the message as it will
|
|
! be decoded, and an integer array i4tone(85) of 9-FSK tone values
|
|
! in the range 0-8.
|
|
|
|
use packjt
|
|
character*22 msg0
|
|
character*22 message !Message to be generated
|
|
character*22 msgsent !Message as it will be received
|
|
integer*4 i4Msg6BitWords(13) !72-bit message as 6-bit words
|
|
integer*1 i1Msg8BitBytes(13) !72 bits and zero tail as 8-bit bytes
|
|
integer*1 i1EncodedBits(207) !Encoded information-carrying bits
|
|
integer*1 i1ScrambledBits(207) !Encoded bits after interleaving
|
|
integer*4 i4DataSymbols(69) !Data symbols (values 0-7)
|
|
integer*4 i4GrayCodedSymbols(69) !Gray-coded symbols (values 0-7)
|
|
integer*4 i4tone(85) !Tone #s, data and sync (values 0-8)
|
|
include 'jt9sync.f90'
|
|
save
|
|
|
|
if(msg0(1:1).eq.'@') then
|
|
read(msg0(2:5),*,end=1,err=1) nfreq
|
|
go to 2
|
|
1 nfreq=1000
|
|
2 i4tone(1)=nfreq
|
|
else
|
|
message=msg0
|
|
do i=1,22
|
|
if(ichar(message(i:i)).eq.0) then
|
|
message(i:)=' '
|
|
exit
|
|
endif
|
|
enddo
|
|
|
|
do i=1,22 !Strip leading blanks
|
|
if(message(1:1).ne.' ') exit
|
|
message=message(i+1:)
|
|
enddo
|
|
|
|
call packmsg(message,i4Msg6BitWords,itype,.false.) !Pack into 12 6-bit bytes
|
|
call unpackmsg(i4Msg6BitWords,msgsent,.false.,' ') !Unpack to get msgsent
|
|
if(ichk.ne.0) go to 999
|
|
call entail(i4Msg6BitWords,i1Msg8BitBytes) !Add tail, make 8-bit bytes
|
|
nsym2=206
|
|
call encode232(i1Msg8BitBytes,nsym2,i1EncodedBits) !Encode K=32, r=1/2
|
|
i1EncodedBits(207)=0
|
|
call interleave9(i1EncodedBits,1,i1ScrambledBits) !Interleave bits
|
|
i1ScrambledBits(207)=0
|
|
call packbits(i1ScrambledBits,69,3,i4DataSymbols) !Pk 3-bits into words
|
|
call graycode(i4DataSymbols,69,1,i4GrayCodedSymbols) !Apply Gray code
|
|
|
|
! Insert sync symbols at ntone=0 and add 1 to the data-tone numbers.
|
|
j=0
|
|
do i=1,85
|
|
if(isync(i).eq.1) then
|
|
i4tone(i)=0
|
|
else
|
|
j=j+1
|
|
i4tone(i)=i4GrayCodedSymbols(j)+1
|
|
endif
|
|
enddo
|
|
endif
|
|
|
|
999 return
|
|
end subroutine gen9
|