subroutine genmsk40(msg,msgsent,ichk,itone,itype) use hashing character*22 msg,msgsent,hashmsg character*32 cwstring character*2 cwstrbit character*4 crpt,rpt(0:63) character*40 pchk_file,gen_file logical first integer itone(144) integer*1 message(16),codeword(32),bitseq(40) integer*1 s8r(8) data s8r/1,0,1,1,0,0,0,1/ data first/.true./ save first,rpt if(first) then do i=0,30 if( i.lt.5 ) then write(rpt(i),'(a1,i2.2,a1)') '-',abs(i-5) write(rpt(i+31),'(a2,i2.2,a1)') 'R-',abs(i-5) else write(rpt(i),'(a1,i2.2,a1)') '+',i-5 write(rpt(i+31),'(a2,i2.2,a1)') 'R+',i-5 endif enddo rpt(62)='RRR ' rpt(63)='73 ' first=.false. endif !####### TEMPORARILY HARDWIRE PCHK AND GEN FILES ################## !These files will need to be installed. pchk_file="peg-32-16-reg3.pchk" gen_file="peg-32-16-reg3.gen" call init_ldpc(trim(pchk_file)//char(0),trim(gen_file)//char(0)) itype=-1 msgsent='*** bad message ***' itone=0 i1=index(msg,'>') if(i1.lt.9) go to 900 call fmtmsg(msg,iz) crpt=msg(i1+2:i1+5) do i=0,63 if(crpt.eq.rpt(i)) go to 10 enddo go to 900 10 irpt=i !Report index, 0-63 if(ichk.lt.10000) then hashmsg=msg(2:i1-1)//' '//crpt call hash(hashmsg,22,ihash) ihash=iand(ihash,1023) !10-bit hash ig=64*ihash + irpt !6-bit report else ig=ichk-10000 endif do i=1,16 message(i)=iand(1,ishft(ig,1-i)) enddo call ldpc_encode(message,codeword) cwstring=" " do i=1,32 write(cwstrbit,'(i2)') codeword(i) cwstring=cwstring//cwstrbit enddo ! write(*,'(a6,i6,2x,a6,i6,2x,a6,i6)') ' msg: ',ig,'rprt: ',irpt,'hash: ',ihash ! write(*,'(a6,32i1)') ' cw: ',codeword bitseq(1:8)=s8r bitseq(9:40)=codeword bitseq=2*bitseq-1 ! Map I and Q to tones. itone=0 do i=1, 20 itone(2*i-1)=(bitseq(2*i)*bitseq(2*i-1)+1)/2; itone(2*i)=-(bitseq(2*i)*bitseq(mod(2*i,40)+1)-1)/2; enddo ! Flip polarity itone=-itone+1 msgsent=msg itype=7 900 return end subroutine genmsk40