mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-13 15:41:50 -05:00
1022a55665
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@8437 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
148 lines
4.2 KiB
Fortran
148 lines
4.2 KiB
Fortran
subroutine genmsk144(msg0,mygrid,ichk,bcontest,msgsent,i4tone,itype)
|
|
! s8 + 48bits + s8 + 80 bits = 144 bits (72ms message duration)
|
|
!
|
|
! Encode an MSK144 message
|
|
! Input:
|
|
! - msg0 requested message to be transmitted
|
|
! - ichk if ichk=1, return only msgsent
|
|
! if ichk.ge.10000, set imsg=ichk-10000 for short msg
|
|
! - msgsent message as it will be decoded
|
|
! - i4tone array of audio tone values, 0 or 1
|
|
! - itype message type
|
|
! 1 = standard message "Call_1 Call_2 Grid/Rpt"
|
|
! 2 = type 1 prefix
|
|
! 3 = type 1 suffix
|
|
! 4 = type 2 prefix
|
|
! 5 = type 2 suffix
|
|
! 6 = free text (up to 13 characters)
|
|
! 7 = short message "<Call_1 Call2> Rpt"
|
|
|
|
use iso_c_binding, only: c_loc,c_size_t
|
|
use packjt
|
|
use hashing
|
|
character*22 msg0
|
|
character*22 message !Message to be generated
|
|
character*22 msgsent !Message as it will be received
|
|
character*6 mygrid
|
|
integer*4 i4Msg6BitWords(13) !72-bit message as 6-bit words
|
|
integer*4 i4tone(144) !
|
|
integer*1, target:: i1Msg8BitBytes(10) !80 bits represented in 10 bytes
|
|
integer*1 codeword(128) !Encoded bits before re-ordering
|
|
integer*1 msgbits(80) !72-bit message + 8-bit hash
|
|
integer*1 bitseq(144) !Tone #s, data and sync (values 0-1)
|
|
integer*1 i1hash(4)
|
|
integer*1 s8(8)
|
|
logical bcontest
|
|
real*8 pp(12)
|
|
real*8 xi(864),xq(864),pi,twopi
|
|
data s8/0,1,1,1,0,0,1,0/
|
|
equivalence (ihash,i1hash)
|
|
logical first
|
|
data first/.true./
|
|
save
|
|
|
|
if(first) then
|
|
first=.false.
|
|
nsym=128
|
|
pi=4.0*atan(1.0)
|
|
twopi=8.*atan(1.0)
|
|
do i=1,12
|
|
pp(i)=sin((i-1)*pi/12)
|
|
enddo
|
|
endif
|
|
|
|
if(msg0(1:1).eq.'@') then !Generate a fixed tone
|
|
read(msg0(2:5),*,end=1,err=1) nfreq !at specified frequency
|
|
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
|
|
|
|
if(message(1:1).eq.'<') then
|
|
call genmsk40(message,msgsent,ichk,i4tone,itype)
|
|
if(itype.lt.0) go to 999
|
|
i4tone(41)=-40
|
|
go to 999
|
|
endif
|
|
|
|
call packmsg(message,i4Msg6BitWords,itype,bcontest) !Pack into 12 6-bit bytes
|
|
call unpackmsg(i4Msg6BitWords,msgsent,bcontest,mygrid) !Unpack to get msgsent
|
|
|
|
if(ichk.eq.1) go to 999
|
|
i4=0
|
|
ik=0
|
|
im=0
|
|
do i=1,12
|
|
nn=i4Msg6BitWords(i)
|
|
do j=1, 6
|
|
ik=ik+1
|
|
i4=i4+i4+iand(1,ishft(nn,j-6))
|
|
i4=iand(i4,255)
|
|
if(ik.eq.8) then
|
|
im=im+1
|
|
i1Msg8BitBytes(im)=i4
|
|
ik=0
|
|
endif
|
|
enddo
|
|
enddo
|
|
|
|
ihash=nhash(c_loc(i1Msg8BitBytes),int(9,c_size_t),146)
|
|
ihash=2*iand(ihash,32767) !Generate the 8-bit hash
|
|
i1Msg8BitBytes(10)=i1hash(1) !Hash code to byte 10
|
|
|
|
mbit=0
|
|
do i=1, 10
|
|
i1=i1Msg8BitBytes(i)
|
|
do ibit=1,8
|
|
mbit=mbit+1
|
|
msgbits(mbit)=iand(1,ishft(i1,ibit-8))
|
|
enddo
|
|
enddo
|
|
|
|
call encode_msk144(msgbits,codeword)
|
|
|
|
!Create 144-bit channel vector:
|
|
!8-bit sync word + 48 bits + 8-bit sync word + 80 bits
|
|
bitseq=0
|
|
bitseq(1:8)=s8
|
|
bitseq(9:56)=codeword(1:48)
|
|
bitseq(57:64)=s8
|
|
bitseq(65:144)=codeword(49:128)
|
|
bitseq=2*bitseq-1
|
|
|
|
xq(1:6)=bitseq(1)*pp(7:12) !first bit is mapped to 1st half-symbol on q
|
|
do i=1,71
|
|
is=(i-1)*12+7
|
|
xq(is:is+11)=bitseq(2*i+1)*pp
|
|
enddo
|
|
xq(864-5:864)=bitseq(1)*pp(1:6) !last half symbol
|
|
do i=1,72
|
|
is=(i-1)*12+1
|
|
xi(is:is+11)=bitseq(2*i)*pp
|
|
enddo
|
|
! Map I and Q to tones.
|
|
i4tone=0
|
|
do i=1,72
|
|
i4tone(2*i-1)=(bitseq(2*i)*bitseq(2*i-1)+1)/2;
|
|
i4tone(2*i)=-(bitseq(2*i)*bitseq(mod(2*i,144)+1)-1)/2;
|
|
enddo
|
|
endif
|
|
|
|
! Flip polarity
|
|
i4tone=-i4tone+1
|
|
|
|
999 return
|
|
end subroutine genmsk144
|