WSJT-X/lib/ft8/genft8.f90
2019-04-18 14:16:39 -05:00

47 lines
1.1 KiB
Fortran

subroutine genft8(msg,i3,n3,msgsent,msgbits,itone)
! Encode an FT8 message, producing array itone().
use packjt77
include 'ft8_params.f90'
character msg*37,msgsent*37
character*77 c77
integer*1 msgbits(77),codeword(174)
integer itone(79)
integer icos7(0:6)
integer graymap(0:7)
logical unpk77_success
data icos7/3,1,4,0,6,5,2/ !Costas 7x7 tone pattern
data graymap/0,1,3,2,5,6,4,7/
i3=-1
n3=-1
call pack77(msg,i3,n3,c77)
call unpack77(c77,0,msgsent,unpk77_success)
read(c77,'(77i1)',err=1) msgbits
if(unpk77_success) go to 2
1 msgbits=0
itone=0
msgsent='*** bad message *** '
go to 900
entry get_ft8_tones_from_77bits(msgbits,itone)
2 call encode174_91(msgbits,codeword) !Encode the test message
! Message structure: S7 D29 S7 D29 S7
itone(1:7)=icos7
itone(36+1:36+7)=icos7
itone(NN-6:NN)=icos7
k=7
do j=1,ND
i=3*j -2
k=k+1
if(j.eq.30) k=k+7
indx=codeword(i)*4 + codeword(i+1)*2 + codeword(i+2)
itone(k)=graymap(indx)
enddo
900 return
end subroutine genft8