program ft4code ! Provides examples of message packing, LDPC(174,91) encoding, bit and ! symbol ordering, and other details of the FT8 protocol. use packjt77 include 'ft4_params.f90' !Set various constants include 'ft4_testmsg.f90' parameter (NWAVE=NN*NSPS) character*37 msg,msgsent character*77 c77 character*9 comment character bad*1,msgtype*18 integer itone(NN) integer*1 msgbits(77),rvec(77),codeword(174) data rvec/0,1,0,0,1,0,1,0,0,1,0,1,1,1,1,0,1,0,0,0,1,0,0,1,1,0,1,1,0, & 1,0,0,1,0,1,1,0,0,0,0,1,0,0,0,1,0,1,0,0,1,1,1,1,0,0,1,0,1, & 0,1,0,1,0,1,1,0,1,1,1,1,1,0,0,0,1,0,1/ ! Get command-line argument(s) nargs=iargc() if(nargs.ne.1 .and. nargs.ne.3) then print* print*,'Program ft4code: Provides examples of message packing, ', & 'LDPC(174,91) encoding,' print*,'bit and symbol ordering, and other details of the FT4 protocol.' print* print*,'Usage: ft4code [-c grid] "message" # Results for specified message' print*,' ft4code -t # Examples of all message types' go to 999 endif call getarg(1,msg) !Message to be transmitted if(len(trim(msg)).eq.2 .and. msg(1:2).eq.'-t') then nmsg=NTEST else call fmtmsg(msg,iz) !To upper case; collapse multiple blanks nmsg=1 endif write(*,1010) 1010 format(4x,'Message',31x,'Decoded',29x,'Err i3.n3'/100('-')) do imsg=1,nmsg if(nmsg.gt.1) msg=testmsg(imsg) ! Generate msgsent, msgbits, and itone i3=-1 n3=-1 call pack77(msg,i3,n3,c77) call genft4(msg,0,msgsent,msgbits,itone) call encode174_91(msgbits,codeword) msgtype="" if(i3.eq.0) then if(n3.eq.0) msgtype="Free text" if(n3.eq.1) msgtype="DXpedition mode" if(n3.eq.2) msgtype="EU VHF Contest" if(n3.eq.3) msgtype="ARRL Field Day" if(n3.eq.4) msgtype="ARRL Field Day" if(n3.eq.5) msgtype="Telemetry" if(n3.ge.6) msgtype="Undefined type" endif if(i3.eq.1) msgtype="Standard msg" if(i3.eq.2) msgtype="EU VHF Contest" if(i3.eq.3) msgtype="ARRL RTTY Roundup" if(i3.eq.4) msgtype="Nonstandard calls" if(i3.ge.5) msgtype="Undefined msg type" if(i3.ge.1) n3=-1 bad=" " comment=' ' if(msg.ne.msgsent) bad="*" if(n3.ge.0) then write(*,1020) imsg,msg,msgsent,bad,i3,n3,msgtype,comment 1020 format(i2,'.',1x,a37,1x,a37,1x,a1,2x,i1,'.',i1,1x,a18,1x,a9) else write(*,1022) imsg,msg,msgsent,bad,i3,msgtype,comment 1022 format(i2,'.',1x,a37,1x,a37,1x,a1,2x,i1,'.',1x,1x,a18,1x,a9) endif enddo if(nmsg.eq.1) then write(*,1030) ieor(msgbits,rvec) 1030 format(/'Source-encoded message before scrambling, 77 bits: ',/77i1) write(*,1032) rvec 1032 format(/'Scrambling vector, 77 bits: ',/77i1) write(*,1034) msgbits 1034 format(/'Source-encoded message after scrambling, 77 bits:'/77i1) write(*,1036) codeword(78:91) 1036 format(/'14-bit CRC: ',/14i1) write(*,1038) codeword(92:174) 1038 format(/'83 Parity bits: ',/83i1) write(*,1040) 0,itone,0 1040 format(/'Channel symbols (105 tones):'/ & 'R Sync',13x,'Data',13x, & ' Sync',13x,'Data',13x, & ' Sync',13x,'Data',13x,' Sync R'/ & i1,1x,4i1,1x,29i1,1x,4i1,1x,29i1,1x,4i1,1x,29i1,1x,4i1,i2) endif 999 end program ft4code